The world of solenoid valves has developed its own abbreviations and terminology to deal with the ever increasing permutations of functionality and layout of the solenoid valve as its range grows to meet the demands of the industries it serves.

For those new to solenoid valves and even those who work with them everyday it is often useful to have a reference to terms commonly used when describing a solenoid valve, its function or specification.

Solenoid Valve Terminology A

ACME Thread : A flat topped screw thread for power transmission. This thread has a 29° included angle between adjacent thread faces compared with the 60° angle of the U.S. standard «V» thread.

Actuator : A device that converts manual, hydraulic, pneumatic or electrical energy into mechanical motion to open or close a valve.

AGA - American Gas Association : The American Gas Association represents companies delivering natural gas to customers to help meet their energy needs. AGA members are committed to delivering natural gas safely, reliably, cost-effectively and in an environmentally responsible way. AGA advocates the interests of its members and their customers, and provides information and services promoting efficient demand and supply growth, and operational excellence, in the safe, reliable and efficient delivery of natural gas.

Aggressive Media : Aggressive media means that the liquid or gas being controlled is very corrosive such as strong Acids and Alkali's. Valves for aggressive media.

Air Operated Valve : An air operated valve is a valve that utilises compressed air typically from 3 to 8 bar pressure to change state or move, either directly or indirectly via solenoid control. Examples of air operated valves would be angle seat piston valves, pneumatic solenoid valves, pneumatic cylinders, air actuators and externally controlled coaxial valves.

Air Vent Valve : A valve installed into a liquid pipeline and an air vent valve at the top open to atmosphere which is controlled by a floating ball lever valve. The valve will automatically let air or gas out of or away from a liquid carrying pipe.

AISI American Iron & Steel Institute : AISI is an association of steel makers which sets standards for the chemical and physical properties of steel and iron in various shapes and forms, such as: pipe, tubing, sheet, strip, wire. AISI’s Mission is to influence public policy, educate and shape public opinion in support of a strong, sustainable U.S. and North American steel industry committed to manufacturing products that meet society’s needs.

All welded Construction Valve : A valve that has been completely welded and cannot be disassembled or repaired on site.

Alloy Steel : Steel consisting mostly of Iron with some other elements such as Chromium, Nickel, Manganese or Vanadium that have been added during the manufacturing process.

Ambient Temperature : The ambient temperature refers to the temperature in °C or °F of the surrounding atmosphere. For example as with common solenoid valves the ambient temperature rating will be +50°C which means the coil can be energised and used in an area up to but not exceeding +50°C.

Amp : Amps (Amperes) is the measurement of electrical current when the solenoid valve is energised. Amps = Watts divided by Volts. Typically the lower the voltage the higher the Amperes, and the higher the voltage the lower the Amperes.

Anchor Pin : A pin welded onto the body of ball valves. This pin aligns the adapter plate and restrains the plate and gear operator from moving while the valve is being operated.

Angle Pattern Valve : Angle pattern valve is a valve whose ends are at right angles to each other for installation at a junction between vertical and horizontal pipelines. Angle pattern valve can also be a valve whose main body or actuator are at an angle greater too or less than 90° to the inlet and outlet ports, such as an angle seat pneumatic piston valve.

ANR (Atmosphere Normale de Reference) is quantity of air at conditions 1.01325 bar absolute, 20oC and 65% RH (Relative Humidity)

API American Petroleum Institute : The principal U.S. oil company trade association. It has some standards and specification writing functions, such as well head components and pipeline valves.

API SPEC 6D : Specification for Pipeline Valves. API Specification 6D is an adoption of ISO 14313: 1999, Petroleum and Natural Gas Industries-Pipeline Transportation Systems-Pipeline Valves. This International Standard specifies requirements and gives recommendations for the design, manufacturing, testing and documentation of ball, check, gate and plug valves for application in pipeline systems.

API 526 : Flanged Steel Pressure Relief Valves. The standard is a purchase specification for flanged steel pressure relief valves. Basic requirements are given for direct spring-loaded pressure relief valves and pilot-operated pressure relief valves as follows: orifice designation and area; valve size and pressure rating, inlet and outlet; materials; pressure temperature limits; and centre to face dimensions, inlet and outlet.

API 527 : Seat Tightness of Pressure Relief Valves R(2002). Describes methods of determining the seat tightness of metal- and soft-seated pressure relief valves, including those of conventional, bellows, and pilot-operated designs.

ANSI/API STD 594 : Check Valves: Flanged, Lug, Wafer and Butt-welding. API Standard 594 covers design, material, face-to-face dimensions, pressure-temperature ratings, and examination, inspection, and test requirements for two types of check valves.

API 598 : Valve Inspection and Testing. The standard covers inspection, supplementary examination, and pressure test requirements for both resilient-seated and metal-to-metal seated gate, globe, plug, ball, check, and butterfly valves. Pertains to inspection by the purchaser and to any supplementary examinations the purchaser may require at the valve manufacturer's plant.

ANSI/API 599 : Metal Plug Valves - Flanged, Threaded and Welding Ends. A purchase specification that covers requirements for metal plug valves with flanged or butt-welding ends, and ductile iron plug valves with flanged ends, in sizes NPS 1 through NPS 24, which correspond to nominal pipe sizes in ASME B36.10M. Valve bodies conforming to ASME B16.34 may have flanged end and one butt-welding end. It also covers both lubricated and non lubricated valves that have two-way coaxial ports, and includes requirements for valves fitted with internal body, plug, or port linings or applied hard facings on the body, body ports, plug, or plug port.

ANSI/API 600 : Bolted Bonnet Steel Gate Valves for Petroleum and Natural Gas Industries - Modified National Adoption of ISO 10434:1998.

API 602 : Compact Steel Gate Valves - Flanged, Threaded, Welding, and Extended-Body Ends. The standard covers threaded-end, socket-welding-end, butt-welding-end, and flanged-end compact carbon steel gate valves in sizes NPS4 and smaller.

ANSI/API 603 : Corrosion-Resistant, Bolted Bonnet Gate Valves - Flanged and Butt-Welding Ends. The standard covers corrosion-resistant bolted bonnet gate valves with flanged or butt-weld ends in sizes NPS 1/2 through 24, corresponding to nominal pipe sizes in ASME B36.10M, and Classes 150, 300, and, 600, as specified in ASME B16.34.

ANSI/API 607 : Fire Test for Soft-Seated Quarter Turn Valves. The standard covers the requirements for testing and evaluating the performance of straightway, soft-seated quarter-turn valves when the valves are exposed to certain fire conditions defined in this standard. The procedures described in this standard apply to all classes and sizes of such valves that are made of materials listed in ASME B16.34.

API 609 : Butterfly Valves: Double Flanged, Lug- and Wafer-Type. The standard covers design, materials, face-to-face dimensions, pressure-temperature ratings, and examination, inspection, and test requirements for gray iron, ductile iron, bronze, steel, nickel-base alloy, or special alloy butterfly valves that provide tight shut off in the closed position and are suitable for flow regulation.

API 6FA : Specification for Fire Test for Valves. The standard covers the requirements for testing and evaluating the performance of API Spec 6A and Spec 6D valves when exposed to specifically defined fire conditions.

API 6FC : Fire Test for Valve with Automatic Backseats. The standard covers the requirements for testing and evaluating the performance of API Spec 6A and Spec 6D valves with automatic backseats when exposed to specifically defined fire conditions.

API 6RS : Referenced Standards for Committee 6, Standardization of Valves and Wellhead Equipment.

API 11V6 : Design of Continuous Flow Gas Lift Installations Using Injection Pressure Operated Valves. The standard sets guidelines for continuous flow gas lift installation designs using injection pressure operated valves.

ANSI/API RP 11V7 : Recommended Practice for Repair, Testing, and Setting Gas Lift Valves. The standard applies to repair, testing, and setting gas lift valves and reverse flow (check) valves.

API 520-1 : Sizing, Selection, and Installation of Pressure-Relieving Devices in Refineries: Part I - Sizing and Selection. The recommended practice applies to the sizing and selection of pressure relief devices used in refineries and related industries for equipment that has a maximum allowable working pressure of 15 psig (1.03 bar g or 103 kPa g) or greater.

API 520-2 : Recommended Practice 520: Sizing, Selection, and Installation of Pressure-Relieving Devices in Refineries-Part II, Installation. The recommended practice covers methods of installation for pressure-relief devices for equipment that has a maximum allowable working pressure of 15 psig (1.03 bar g or 103 kPa g) or greater. It covers gas, vapour, steam, two-phase and incompressible fluid service.

ANSI/API 574 : Inspection Practices for Piping System Components. The standard covers the inspection of piping, tubing, valves (other than control valves) and fittings used in petroleum refineries.

ANSI/API 576 : Inspection of Pressure Relieving Devices. The recommended practice describes the inspection and repair practices for automatic pressure-relieving devices commonly used in the oil and petrochemical industries.

ANSI/API 608 : Metal Ball Valves - Flanged and Butt-Welding Ends. The standard covers Class 150 and Class 300 metal ball valves that have either butt-welding or flanged ends and are for use in on-off service.

ASME American Society of Mechanical Engineers : A professional society that publishes technical books, papers, codes and standards, of principal interest is the ASME Boiler and Pressure Vessel Code, which is referenced for many aspects of valve making, although not for the valves themselves.

Assisted Lift : An assisted lift solenoid valve sometimes known as kick pilot or hung diaphragm have a mechanical connection between the armature and either a diaphragm or piston to "assist" the valve into the open or closed position and thus does not reply or system pressure differentials for operation and control.

ASTM International : ASTM International, formerly known as the American Society for Testing and Materials (ASTM), is a globally recognised leader in the development and delivery of international voluntary consensus standards. Today, some 12,000 ASTM standards are used around the world to improve product quality, enhance safety, facilitate market access and trade, and build consumer confidence.

ATEX - Hazardous Area : ATEX hazardous area is a European initiative to ensure the safety of products such as solenoid valves used in potentially explosive gas and or dust atmospheres. It is an EU law that all products that could provide ignition to a potentially explosive atmosphere to be supplied to specific requirements, under controlled conditions by a manufacturer certified compliant to the directive by an independent notification body.

It is not simply a generated spark by a solenoid coil caused by coil failure or short circuit it also applies to temperature limitations under normal working conditions to avoid flash point ignitions. ATEX solenoid valve have been manufactured to comply with ATEX standards such as EEx m II T4 encapsulated coils with thermal fuses, EEx d II C T4, T5 or T6 coils encased in stainless steel or aluminium flame proof enclosure and finally EEx ia IIC T4 or T6 intrinsically safe low power coils.

Atmospheric Gases : Atmospheric gases are gases that are found in the atmosphere which we breath and are also found in compressed air systems. Atmospheric gases are by volume, 78.09% Nitrogen, 20.95% Oxygen, 0.93% Argon, 0.039% Carbon Dioxide and small trace amounts of other gases such as Argon 0.93%, Carbon Dioxide 0.038%, Krypton 0.001%, Methane 0.0001%, Helium 0.0005% and Neon 0.0018%. There is of course traces of water vapour, dust and sand particles to be included which are suspended in the air, hence the need for filtration and water removal systems for air compressors.

Atmospheric Pressure : See Pressure. Atmospheric pressure is typically measured at 1 bar or 14.71 psi, being the measured atmosphere or ambient air pressure at sea level.

AWS American welding Society : American Welding Society (AWS) was founded in 1919 as a multifaceted, non profit organization with a goal to advance the science, technology and application of welding and related joining disciplines. AWS New World Headquarters render 2012 From factory floor to high-rise construction, from military weaponry to home products, AWS continues to lead the way in supporting welding education and technology development to ensure a strong, competitive and exciting way of life for all Americans.

Austenitic Stainless Steel : The common stainless steel, where the primary micro structure is austenite and the composition primarily iron, but also includes both chromium and nickel. The stainless steel is designated as 300 series such as 302, 303, 304, 316, CF8M, etc.

Solenoid Valve Terminology B

Banjo Fitments : Banjo fitting is also known as an internally inserted bolt, consists of is a spherical union hollow fitting with a hollow male bolt through it that can rotate inside the eye. There is a flow path through the both and eyelet for the transfer of fluid or gas. This allows for a flexible pipe to be connected or screwed into a valve or manifold by only rotating the bolt and not the whole fitting. Typically used in small confined spaces.

BAR : Bar is the measure of pressure, 1 bar equals 14.5psi. See pressure

BBL : An abbreviation for "barrel", used to express liquid volume. One barrel of oil is equal to 42 U.S. gallons.

BDV Blow Down Valve : A manually actuated ball valve installed at the end of an extended drain line to vent, release and drain pressure system away and out to atmosphere or drain.

Belleville Spring : A spring similar to a dished shaped washer, used in some ball valves to push the seats against the gate.

Bending Moment : A mechanical bending load or force applied to a part at right angles to its surface or axis. The product of the force times the perpendicular distance to the point of restraint is usually expressed in pound-feet or torque.

BGO - Bevel gear Operated : Valve actuation by means of a set of bevel gears having pinion axis at right angles to a larger ring gear. The gear ratio determines the mechanical multiplication of the torque achieved. i.e. a bevel gear ratio of 4 to 1 will increase the initial torque and turns by the same factor.

Bi-directional : Bi-directional means that the flow of media though the solenoid valve can be in either direction from inlet to outlet or from outlet to inlet. Bi-directional valves are good for maintaining and controlling back pressure such as a coaxial valve or angle seat piston valve.

Bleed Orifice : A bleed orifice is a small hole or flow path most typically found in the side of a flexible elastomer diaphragm or piston assembly of pilot operated or assisted lift solenoid valves, that allows the media entering the valve to pass through and enter above the diaphragm or piston.

Body Material : The body material of a valve refers to the valve main body material of construction for example a solenoid valve with a brass body will have a Brass body, but may have other materials of construction internally or externally.

Bolt : A long externally threaded fastener with a square or hexagonal nut at one end. Used to connect flange connections or valve bonnets (tops) to the valve base.

Bolt Circle : The circle that passes through the centre of all the flange bolt holes.

Bolted Bonnet : A valve bonnet or top body cover that is bolted to or restrained and held in place with bolts.

Bolted Construction : A bolted construction valve or solenoid valve whose valve bonnet and body or pressure shell elements are bolted together. Bolted construction valves can be disassembled and repaired on site.

Bolting Sets : Bolts or threaded studs with nuts used to install a valve between pipe line flanges.

Bonnet : The bonnet of a solenoid valve is the valve top body cover that typically sandwiches the diaphragm between it and the lower valve body, to which the armature assembly and solenoid coil are fitted. The bonnet of other valves will be the same top part of the valve body whish guides the stem and adapts to extensions or operators.

Bore : The inside diameter of the smallest opening for the media passing through the valve. The diameter of the hole in a ball valve will be the diameter of the hole in the ball, the diameter of the bore of a gate valve is the diameter of te opening when the gate is situated. Typically the inside diameter of the valve seat.

BREEAM : BREEAM sets the standard for best practice in sustainable building design, construction and operation and has become one of the used and recognised standards of a buildings environmental performance standards. Breeam motivates design engineers, clients and BMS installers to reduce energy consumption, low carbon foot prints to minimise energy demands before considering energy efficiency and low carbon technologies.

Brinell Hardness Number : A brinell hardness number indicates the metal hardness using the brinell scale. Can be converted to Rockwell B&C hardness scale.

BRV Body Relief Valve : A relief valve installed on ball valves to provide for the relief of excess body pressure caused by thermal expansion.

BSP Thread : BSP is British Standard Pipe thread, which can be BSPP parallel or BSPT tapered thread.

Bubble Tight Solenoid Valve : Is a solenoid valve that when closed will shut and prevent any detectable leakage through the valve. This is typically less than or equal too a measured 0.0001 cc per second of air, which is used for liquids which are much thicker (water is 25 times thicker than air) would be substantially less.

Buried Service : A valve application where the valve is installed below ground level, and could be in a damp or wet environment with potential for flooding.

Burst pressure : The burst pressure of a valve the the extreme pressure required which will cause the valve to leak externally from the one or more pressure containing parts. Typically valve design working pressure is 25% - 33% of the valve burst pressure.

Butt Weld Ends : Butt weld end connections of a valve have been suitably prepared inn readiness for welding into a pipeline.

Butterfly Valve : A short face-to-face valve which has a movable vane, in the centre of the flow stream, which rotates 90 degrees as the butterfly valve opens and closes, much like the old style webber carburettor. By rotation of its disc butterfly valve controls the flow. It may be used for on – off applications as well as flow modulating. Connection types may be wafer, lug, flanged, groove end, threaded and butt welded. For components do not differ for different connection types, valves shown below may be taken as reference for all

  • Concentric butterfly valve : Valve body, stem and obturator are concentric.
  • Double eccentric butterfly valve : First eccentricity is between the valve body, obturator and the second eccentricity is between the stem and operator.
  • Triple eccentric butterfly valve: In addition to the double eccentric type, the third eccentricity is the conical shape of the obturator seating face. Therefore operator only contacts body seating face when closed.

BVR - Ball Valve Regulator : An automatic throttling valve controlling flow or pressure in a pipeline; comprising a package involving a ball valve, actuator, position-er and controlling instrument.

Bypass : A system of pipes and control valves to allow the flow of media to divert around another valve or vessel, so that the valve or vessel can be isolated and then removed or repaired without the need to stop the flow of media.

Solenoid Valve Terminology C

Carbon Steel : Iron containing carbon in the form of carbides, about 0.1 to 0.3 percent carbon with no other alloying elements other than the sulphur, phosphorus, and other elements present in almost all steels.

Cap Screw : Cap Screw is a fastener having a head and whose shank is normally threaded throughout its entire length. Not used with a nut, but rather engagement is made with a female thread in the piece to be joined.

Capacity Factor : See flow factors

Cast : The form of a particular part of a valve, where the basic shape is formed by moulding rather than fabricating.

Cast Iron : The common term for cast Gray iron or iron containing flake carbon in the range of 2% to 4.3%. Cast iron is brittle, exhibiting very little ductility before fracturing.

Casting : A part typically meal that has been produced or formed by pouring hot molten metal into a mould.

Certificate of Conformity : Certificate of conformity or CofC is a company headed letter or certificate supplied with the goods from the valve supplier stating that the goods are in accordance with the customer purchase order.

Chain Wheel Operated Valve (CWOV) : A valve mounted elsewhere either above, below or behind operated by an hand wheel via a chain and sprocket mechanism.

Characterised Ball or Gate Valve : A ball valve or gate valve whose port has been specifically modified to provide a specific flow adjustment or throttling capability.

Charpy Test : Charpy test is a mechanical test conducted on a precisely machined sample of the steel to be tested. The sample is clamped in a special machine and subjected to a lateral hammer blow. This test provides a relative measure of the toughness of steel or its resistance to shock or impact loads. Often required for low temperature applications where testing is done at the expected minimum service temperature.

Check Valve or Non Return Valve : A one-directional valve which prevents reversal of flow by means of the check mechanism, the valve being opened by the flow of fluid and closed by the weight of the check mechanism when the flow ceases, or by back pressure.

Chevron Packing : Chevron packing is a type of packing used in packing boxes consisting of a nest of «V» cross-section rings.

CIF : CIF Cost Insurance and Freight including insurance charges, see latest Intercoms. Similar to F.O.B. Free On Board.

City Gate Gas Station : The metering and pressure reducing station where gas is transferred from a high pressure cross-country transmission line to a low pressure distribution piping system within a city or town.

Clapper : The hinged closure element or door of a swing disc check non return valve.

Clarified Water : Clarified water is process water with posible small fines or fragments of paper stock.

Class : A designation of pressure capability or pressure rating expressed as a dimensionless number. The class rating charts give actual pounds per square inch maximum allowable pressure at a given temperature.

Clevis : A "U" shaped connecting yoke at the end of a valve stem or rod, between the ends of which a gate or other valve part may be pinned or bolted

Closing Time : The closing time of a valve is the time required for the valve to move from the fully open position into the fully closed position.

Closure Element : The moving part of a control valve, positioned within the flow stream, that controls flow through the valve. either Ball, Gate, Plug, Clapper, Disc etc, are the specific names for closure elements.

Coal Gasification : The process of manufacturing natural gas from coal

Coils for solenoid valves : A solenoid coil is basically an electro magnet or copper wire wound around a central bobine that generates a magnetic filed when electrical power is applied. Solenoid coils come is various sizes, control voltages from 6 volt to 415volt, power levels from 1 watt to 150 watts, can be round metal cased with electrical wires or thermal set resin square or rectangular with 2 or 2 +earth electrical spades on one side to accept an electrical connector. Designed to magnetically lift (solenoid) an internal valve armature to open or close a valve.

Coil Class : The class of solenoid coil is the effective insulation temperature rating or stability during constant heating with ambient temperatures up to +35ºC. The temperature rating or heat class of a solenoid valve and not the over temperature, which is typically given for example as a Class..

Coil Power Ratings : Solenoid coils all have assigned power ratings which is the amount of electrical power they are designed to consume, the higher the power level the stronger the magnetic field generated.

  • DC (Direct current) solenoid coils power level is given as Watts, the power of this coil is stable. A 15 watt solenoid coil working at 24vDC will consume 0.625 Amps. Watts = Volts x Amps hence Amps = 15 watts divided by 24 volts = 0.625 Amps.
  • AC (alternating Current) solenoid coils power level is given as VA (Volt Amps), the power of this coil has two stages. Stage 1 INRUSH CURRENT is a higher energy requirement to lift an armature assembly. Stage 2 HOLDING CURRENT is a reduced energy requirement as it is simply holding the armature in position. Or another analogy is a weight lifter - requires a lot of strength to lift a weight but when arms locked in position is much easier to hold.

An example of a 17VA AC coil would be 17VA holding but 23VA Inrush. At 230vAC this would equate to (W=Volts X Amps) Inrush 0.1 Amps, Holding 0.0739 Amps.

Coil Voltage : Solenoid coil Voltage (Volts) is required voltage at which the solenoid coil must be energised, typically with a small tolerance of +/- 10%, so a 230 volt solenoid coil would work correctly between 207 volt and 253 volts.

Compressor : A device which converts mechanical, electrical, hydraulic or pneumatic energy into increased gas or typically air pressure.

Concentric : A valve having the same centres.

Connector : Electrical DIN 43650 connectors provide a reliable interface for connection / disconnection from hydraulic and pneumatic valves, pressure switches, motor drives and other electrically driven equipment and components. Electrical connectors are available in a range of specific sizes such as:

  • Form A EN175301-803 ISO4400 - 28mm square (18mm between electrical contacts)
  • Industrial Form B - 28mm by 21mm (11mm between electrical flat shape contacts)
  • Form B EN175301-803 (ISO6952) - 28mm by 21mm (10mm between electrical ] shape contacts)
  • Form C ISO15217 - 15.9mm by 15.6mm (8mm between electrical contacts)

Contaminant : A particle or unusual material which is foreign to the typical fluid or gas media of the valve, ie.e the valve has been contaminated.

Control Valve : A valve that controls a process variable, such as pressure, flow or temperature by modulating or simply opening in response to a signal from a controller.

Controller : A control device that measures a controlled system variable, compares it with a predetermined system setting and signals the actuator or valve to re-adjust the opening of the valve in order to re-establish the original control system settings.

Core : The core is the soft magnetic 430F stainless steel part of the solenoid valve sometimes referred to as the armature, which is the part that moves within the generated magnetic field.

Core Spring : The core spring or armature return spring typically 302 stainless steel that returns the armature to its default position when the solenoid coil is de-energised.

Core Tube : The core tube or armature tube is a solenoid valve stainless steel or brass tube which is closed at one end, isolates the media in the valve from the external solenoid coil and parts, that holds the armature and core spring. The core tube screws into or if flange mounted onto the valve bonnet or valve top cover.

Corrosion : The deterioration or loss of a material due to chemical action.

Crude Oil : Unrefined "crude" or "Raw" petroleum oil that has come directly from the oil well. Crude oil is classification according to API degree. The API degree indicates if crude oil floats on water or sinks. Light crude oils flow easily and contain more volatile components, while extra heavy crude oils are highly viscous to almost tar like and show a higher density. Intermediate crude oil will be between these levels.

  • Light Crude Oil: API gravity higher than 31.1º API (less than 870Kg/m³)
  • Medium Crude Oil: API gravity from 31.1º API to 22.3º API (870 to 920 Kg/m³)

Crude oil according to sulphur content can be attributed as follows:

  • Sweet crude oil with Sulphur content up to 1%
  • Sour crude oil with Sulphur content above 1%.

Cryogenic : Cryogenic applies to any temperature below -150°C

Cv flow factor : The capacity flow factor for a valve or valve flow coefficient, specifies the number of gallons of water (20°C) per minute that will flow through the valve when fully open with a pressure drop of 1 psi. Cv can also be given as litres a minute of water with 1 bar pressure drop if specified as so.

CWP - cold working pressure : The maximum working pressure in PSI (pounds per square inch), in which a valve may be operated. Sometimes referred to as MWP or Maximum working Pressure.

Cycle : A single complete valve operation from fully closed to fully open and back to fully closed again is called a complete cycle.

Cyclic Timers : Much like timers these are electrical devices installed into electrical circuits that control the electrical power supply to the valve and will offer a pre-set adjustable automated control for valves. As the timer works on a cycle it will constantly repeat the same set cycle until electrical power is removed, when power is reapplied the cycle timer will begin it cycle from the beginning. Cycle timers are typically adjustable between 0.5 to 10 seconds power ON, with an adjustable power off cycle between 0.5 to 60 minutes, other time sequences are available along with single shot and delay shot timers.

Current Drain : The amount of current that flows through a solenoid coil when it is energised / powered

Solenoid Valve Terminology D

Diaphragm : A diaphragm is a round or square sheet of elastomer rubber compound typically sandwiched between the upper and lower valve body made from either NBR, EPDM or FKM that rests across a sealing face inside the valve that either directly or indirectly allows or prevents the flow of media though the valve. Typically reinforced with Nylon and supported by either an external stainless steel disc or internal metal support to give additional strength to withstand the pressure of media trying to pass through the solenoid valve.

De-energised : The de-energised state of a solenoid valve is with no electrical power supplied to the solenoid valve also known as a fail-safe position.

Degreased : Degreased solenoid valves are typically used for oxygen service, these valves are either manufactured in clean grease and oil free environments or have been disassembled and cleaned in a special non flammable water based solvent to remove any traces of grease, oil or lubricant that could ignite within the oxygen.

Delrin (POM) : Delrin is barnd of Dupint it is a strong thermoplastic used for seal and some plastic valve body materials. It is a type of Polyoxymethylene (acetal, polyacetal and polyformaldehyde). Delrin is susceptable to strong acids but offers good heat resistance and low water absorption. Temperature range from -40C to +150C. Delrin or POM is also known as Hostaform, Celecon, Kepital, Duracon, Lupital or Ultraform.

Delta P ΔP : Pressure differential or pressure drop being the pressure difference between the inlet port and outlet port of a valve.

Density : Density of liquid or gas is the mass per unit volume or thickness. The density of water for example is 1 Kg/m³, the thicker the liquid or gas the slower it will move through a solenoid valve. Flow is directly affected by density of media and the flow of liquids can be calculated where:

  • Q = Flow litres a minute
  • ΔP = Pressure drop
  • d = density
  • Kv = flow coefficient of solenoid valve (litres a minute)
  • Q = Kv x √(ΔP/d)²

Devlon : A molecular weight polyamide banded by Devol, designed for high pressure temperature applications. There are various grades of Devlon, the most popular of which is V-API, which is a lightweight,acid, alkai and impart resistant material. Temperature range -40C to +93C.

Dezincification : Dezincification is a form of pitting or corrosion that attacks certain zinc bearing copper-based alloys, often called "yellow brass", when in contact with sea water or fresh water that is high in oxygen and carbon dioxide. ASTM B61 and B62 are "red brass" and are not susceptible to dezincification.

Diaphragm : A round or square thin flexible elastomer seal secured and sealed around the outer edge or occasionally centrally with its unsupported area free to flex and move. Typically controlling the flow of media through a valve by lifting away from a sealing face, or seating back again to prevent flow.

Differential Pressure : A solenoid valve differential pressure is the pressure difference between the valve pressure at the inlet port and the valve pressure at the outlet port. For example a pressure assisted valve that requires a pressure differential of 0.5 bar (7PSI) means that the pressure at the inlet port must be 0.5 bar higher than the back pressure or outlet pressure say 5 bar at inlet and 4.5 bar at outlet would give the same ΔP (delta P = pressure differential).

Dip Tube : A dip tube extending the blow down valve on large gate valves requires a tube which is located inside of the valve. This tube is called the "dip tube" and extends through the bonnet to the bottom of the valve body cavity.

Direct Acting : Direct acting solenoid valves utilise the armature assembly to "directly" open or close the valve by either covering or exposing a flow path to allow or prevent the flow of liquid or gaseous media.

Disc : Disc or valve poppet or plug is the closing element of a globe, gate or regulator valve, moves to and from the valve seat in a direction 90° to the face by means a rotating threaded stem.

Distribution Line : A pipeline which distributes gas or liquid to individual locations, commonly smaller in diameter than the supply line (6" or less) and low pressure under 10 bar

Diverting Valve : A diverting valve is a valve that diverts the flow or liquid or gas media, rather than simple On/Off or open/closed control. Diverting valve examples would be:

  • to divert compressed air to or away from a pneumatic cylinder or actuator
  • to divert from diesel to vegetable oil for a car or lorry.

DOT regulations. Department of Transport : A code of federal regulations setting out the minimum safety requirements for the transportation of hazardous gases or liquids by a pipeline system.

Double Acting : A double acting valve will have two points of control, either two solenoids or two compressed air inlets. There is no fail-safe or automatic full return back as each side will need to be actuated to move the valve fully into the direction of activation.

Double Block and Bleed Valve : The capability of a valve in a pipeline that is under pressure, to have its body cavity pressure bled down or drained to down to atmospheric pressure when the valve is in either the fully closed or fully open position.

DPDT : Double pole double throw electrical switch.

DPST : Double pole single throw electrical switch.

Drain Plug : A fitting located at the bottom or base of a valve, the removal of which allows the draining and flushing the body pressure cavity.

Draw Off Tap : Valves capable of controlling fluids by opening and closing the valve parallel to the seat orifice.

Dry Armature : A dry armature solenoid valve, sometimes called an isolated diaphragm valve is a valve where the media passing through the valve will ONLY come into contact with the valve body material and the sealing material. Dry armature solenoid control valves are used to control very aggressive and corrosive acids and alkali's.

Dry Lube : Dry-film moly disulphide applied as a coating to sliding or rotating parts to reduce frictional drag. Also available is in liquid form that can be mixed with lubricating oils that stick or coats all metal parts to provide fail safe and increased lubrication, will provide continued lubrication for a short time if the oil is removed.

Dynamic Seal : A seal or gasket used to seal between two moving metal parts such as a stem seal, piston seal or shaft 0 ring.

Durometer : A durometer is an instrument for measuring the hardness for synthetic rubber or elastomer seals, measured on a SHORE Hardness scale. For example a WRAS approved EPDM rubber would have a shore hardness of 72, being soft and pliable yet strong enough to withstand mains water pressures.

Duty Ratings : A solenoid duty rating is defined as the electrical power ON time compared to the electrical power OFF time for a solenoid coil. For example a solenoid coil powered ON for 1 minute and then power OFF for 4 minutes would be 1/4 or 25%. If a coil is shown as having a 100% duty cycle rating then the coil can be powered ON 100% of the time but as with all solenoid coils they can only be energised when correctly fitted to the solenoid valve.

Solenoid Valve Terminology E

Eccentric : Eccentric means not having the same centre.

Elastomer ; A natural rubber or synthetic elastic flexible material used for the manufacture of valve O rings, seals, diaphragms and gaskets.

Elbow : An angled pipe fitting typically 45° or 90º that is connected to a pipeline system to change the direction of flow.

Electrical Connection : Solenoid coils are electromagnetic devices that convert electrical energy into a magnetic field. The electrical energy is supplied to the solenoid coil by either lead wires or by means of an electrical connector. The DIN43650 electrical connector is designed to fit directly onto the side of the solenoid coil with the power supply electrical wires entering the connector through a conduit entry point. There are a few sizes such as Form A 28mm square, Form b rectangular and mini Form C 9.8mm square.

Helpful hint: make sure the cable gland is tight fitting to the cable to prevent pulling free and that the cable enters the connector vertically i.e. upwards ↑ to prevent moisture or water ingress.

Electric Valve : An electric valve is a valve that is powered by electrical current such as an electric solenoid valve or an electrically controlled or motorised valve. Electrically actuated valves can be 12vdc, 24vdc, 48vdc or 12vac, 24vac, 48vac, 110vac, 220vac or 380vac and will draw different current (AMPS) according to their valve specification.

Emergency Seat Seal : Emergency seat seal obtains tight shut off in case of an emergency situation, a sealant can be injected into a specially designed groove in the seat rings to seal the valve closed.

EN161 Valves : EN161 is a general safety requirement as described in EN standards in which devices, solenoid valves, automatic gas safety shut off valve, slam shut valves, solenoid valve, automatic safety shut off valves or gas release valves have to guarantee a safe operation for Natural Gas, Mains Gas Burners, Gas Furnaces, Gas Appliances, Gas Heaters and Gas Steam Boilers.

End Bevel : End bevel is a weld end prepared for butt welding, as governed by ANSI B31.4 & B16.25.

End Connection : The type of connection at the connecting ends oor ports of a valve that allows the valve to be installed within a pipeline. Typical end connections would be weld end, flanged end, screwed end.

EPDM seals : EPDM known as (Ethylene Propylene Diene Monomer) is an elastomer seal that is a typical available option for most solenoid valves, and is the preferred choice for WRAS and Wrc solenoid valves for drinking water.

EPDM has good resistance to Heat, Ozone, Oxidising Chemicals, Up to Medium concentration Acids, Alkali's, Fire proof hydraulic fluids, most Ketone's and Alcohols, sunlight, abrasion and tearing.

EPDM has poor resistance to most oils and Fuels, Hydrocarbons, Aromatic and Aliphatic hydrocarbons, halogenated solvents and concentrated acids.

Equivalent : While there is no such thing as an 'exact equivalent' for most valves as any minor difference could be called into question, there are 'replacement or functional equivalents' where one item can be replaced by another to perform the same function. A replacement equivalent valve is one where important factors including form, compliance & key functional factors are equivalent, or in some cases exceed those of the original it replaces.

Erosion : The mechanical wearing away of a metal surface due to corrosion, fluid ingress or contamination which can be accelerated by solid particles.

Explosion Proof : The prevention of explosion by electrical components, through containment in special metal housings, An ATEX requirement for electrical devices, such as solenoids and switches, when exposed to a potentially explosive environments of gases or dusts. See ATEX.

Export Packaging : Strong packaging, cartons or crates required for the safe transportation of goods for export shipping. Includes sealing against a salt atmosphere or sea air freight shipping.

External Coating : External valve coating or painting applied to protect valves against various environments such as sea air, salt water, underground use and normal air exposure.

Solenoid Valve Terminology F

Fabricated Valve : Fabricated valve in which the valve body and valve hub parts are not cast but are formed from sheet plate or pipe and then welded and or bolted together.

Face to Face : The valve length or overall dimension from the inlet face of the valve to the outlet face of the valve (one end to the other end). This dimension is governed by ANSI B16.10 and API—6D to ensure that such valves are mutually interchangeable, regardless of the manufacturer.

Facing : The finish of the front or contact surfaces of flanged fittings, pipework or flanged valves.

Fail-safe Valve : A valve designed to have a fail safe position by means of a return spring so that in the event of power failure the valve will "fail safe" into the desired position. A fail safe closed solenoid valve will automatically return to closed position, a fail-safe open solenoid valve will automatically return to the open position upon power failure.

F.A.S. Free Along Side : FAS or free along side shipping is a term used for sea freight shipping, vendor pays transportation charges to shipping dock alongside the ship.

Female Thread : A female thread is an internal thread ID Internal Diameter of a hole, a male thread will happily screw into a compatible female thread.

Field Serviceable Valve : A field serviceable valve is a valve that can be repaired or serviced whilst installed out in the field or on site, without the need to be returned to the valve supplier or manufacturer.

Fire Gate : A gate or isolation valve that is positioned in a pipeline that can be closed in case of fire and closing the valve prevents the gas in the pipeline from feeding the fire.

Fire Safe : Fire safe is a statement of valve design which indicates the valve is capable of passing certain specified leakage and operational tests after exposure to fire, typically referenced to a particular fire safe classification or specification.

Fittings : Fittings are small adaptors for connecting liquid or gas lines together, such as elbows, tees, nipples, unions, flanges, push in fittings, threaded adaptors and sockets.

FFKM seals : FFKM is an upgraded FKM (see below) elastomer seal with higher working temperature range up to +250°C and offers great chemical resistance to most solvents and chemicals, but being much more difficult to manufacture makes FFKM a very expensive valve seal option.

  • FFKM has good resistance to solvents and chemicals.
  • FFKM has weak resistance to halogenated refrigerants.

FKM seals : FKM known more often by its Brand name Viton® (Dupont Brand) as an Flour-elastomer seal which is a common option available with many solenoid valves.

FKM has excellent heat resistance to 150 degrees centigrade and is commonly used for hot water, acid, alkali, oils, hydrocarbons and salt solutions, Hydrocarbons, many aggressive chemicals, diluted acids, weak alkali's, mineral oils, aliphatic and aromatic hydrocarbons, chlorinated hydrocarbons, sunlight and ozone. FKM has poor resistance to Ketone's and Acetone.

Flange : A flange is a projecting radial collar with bolt holes allowing pipe connection without threads. Flanges are bolted together and provide a means of installing or removing process valves into or out of pipelines without the need to disassemble additional pipework upstream or downstream.

Flanged solenoid valves : Flanges are designated by flange type, pressure rating and size for example PN16 DN50 flange (diameter nominal) 50mm flange type PN with pressure rating 16 bar, alternatively an ANSI150Lb DN100 flange would be a flange type ANSI with internal diameter 100mm or 4" and a pressure rating of 150 psi.

Flat Face : A flange radial surface in which the gasket sealing area or end connecting face is completely flat without any raised point.

Flexible Tube Valve : A special valve using a flexible sleeve or tube which acts as the closure element. Pressure applied to the jacket space surrounding the outside of the tube, controls the opening and closing of the valve.

Float Valves : Pilot operated or float valve is remotely actuated by a small float valve that rises or drops as it floats at a tank water level. The opening or closing of this pilot floating valve directly controls the main tank inlet valve my means of this pilot pressure, without the need for external power supply or control.

Flow : Flow is the movement of liquid or gas media along a pipeline system.

Flow Coefficient : A measure of flow in gallons per minute of water at 20ºC that will flow through a valve with a pressure drop or pressure differential of 1 psi. Other measurements of flow coefficients such as Kv or litres per minute at 1 bar ΔP can also be used, when stipulated.

Flow Factors : Solenoid controlled valves are commonly assigned with a flow coefficient factor, which refers to the amount of media typically water that would be expected to pass though the valve in the open position under certain pressures. As flow rates vary according to system pressures valve users and design engineers can calculate the expected flow for any given valve according to their specific requirements.

Cv flow factor = gallons of water per minute at 60°F which will flow with a 1psig pressure difference. i.e. USGPM flow with 1 psi at inlet and outlet open ended or 10 psi inlet and 9 psi at outlet.

Flow Meters : A flow meter is an instrument designed to measure the flow rate or volume of media travelling along a pipe.

Flow Rate ( K Value) : Kv values or flow coefficients define the flow through a solenoid valve by the metric measurement of water in cubic meters an hour with a pressure differential of 1 bar (difference between inlet and outlet pressure across the solenoid valve) between 5 and 40 degrees Celsius.

Cv values or flow coefficients define the flow through a solenoid valve by the imperial measurement of water in US gallons per minute with a pressure differential of 1 PSI at 60 degree Fahrenheit.

Qn values or flow coefficients define the flow through a pneumatic solenoid valve by the metric measurement of air in litres per minute at 6 bar with 1 bar differential at 20 degree Celsius.

  • 1 CFM = 0.472 litres a second
  • 1 CFM = 0.000472 m³/Second
  • 1 CFM = 28.32 litres a minute

Fluid : A fluid is a liquid or second state of matter, the other states are first state solids which maintain shape and third state gases. Gases can be compressed such as air, oxygen, helium, nitrogen, argon. Liquids or fluids are the second state which are between solid and gas form, which can flow through a pipe or valve and cannot be compressed. Basic fluids would include water and oils etc. Most liquids when cooled sufficiently will condense into solids or when sufficiently heated will turn into a gas form.

F.O.B. Free On Board : Transportation charges are paid by the vendor to the F.O.B. point. Typically freight is FOB factory which means case, title and transportation charges pass to the customer or client at the point the shipment or freight leaves the factory.

Force (Newtons) : Force is measured in Newtons. When a solenoid coil is energised it will exert a magnetic pull or force upon the armature or "Pull in Force", as the plunger moves further into the magnetic field the force applied will increase until the maximum force is achieved at the end of the stroke.

Forging : A metal part that has been formed by heating close to melting point and hammered or pounded into a specific shape.

FPC - Federal Power Commission : FPC is the United States government agency that governs and regulates the natural gas and pipeline industry, as well as other energy industries.

Friction : Friction is the resistance to movement between two contacting surfaces, can also apply to liquids or gases passing along a pipe inner wall generating a drop in pressure ΔP.

Full Bore : A valve whose orifice or smallest point of flow is at least equal to or greater than the size of the connecting port, thus offering very high flow rate and greatly reduced pressure drop.

Full Opening : A valve whose orifice or bore is equal in size to the connecting port, allowing for full flow or similar to full bore.

Full Penetration Weld : Full penetration weld describes the type of weld wherein the weld metal extends across the entire wall thickness of the joint.

Function (Solenoid Valve) : The function of a solenoid valve is given as the number of ports, the number of positions and the fail safe positions. For example of 2/2 way normally closed solenoid valve will be 2 ports (inlet and outlet) with 2 positions (open or closed) with fail-safe position closed i.e. shut preventing flow of media without electrical supply, a 3/2 way normally closed solenoid valve will have 3 ports and 2 positions with fail safe inlet port closed, 5/2 way 5 ports 2 positions or 5/3 way 5 ports 3 positions.

Solenoid Valve Terminology G

G Thread : G Thread is the European symbol for BSP British Standard Thread. G threads can be BSPP Parallel or PSPT Tapered.

Galling : Galling is the tearing of metal caused by severe metal to metal friction typically caused by a lack of lubrication.

Gas : Gas is typically referred to as an air like substance which is not a solid or liquid that is compressible such as Argon, Carbon Dioxide, Carbon Monoxide, Freon Gas, Helium, Methane Gas, Natural Gas, Neon, Nitrogen, Nitrous Oxide, Noble Gas, Oxygen, Ozone, Water Vapour, Xenon.

Gasket : A gasket is a seal or packing material placed between to joints to seal and prevent leakage of media passing through. Gaskets are sometimes referred to as diaphragms, O rings or other sealing materials.

Gate : A gate is typically the closing/opening element of a gate valve or non return valve.

Gate Valve : A gate valve controls the flow of media along a pipe by means of a gate which either lifts away allowing flow or drops down preventing flow along a straight line path through the valve. The ports ends are typically in line, the gate is lifted by a rotating threaded stem with is perpendicular to the valve body, usually with a hand wheel or T bar handle for actuation.

General Purpose : A general purpose valve is a valve used for general purpose or non aggressive or corrosive media in the low pressure range, such as air, water, light oils and vacuum. Typically general purpose valves will be Brass bodied, with NBR seals suited to pressures up to 10 bar (150 psi)

Globe Valve : An ON/OFf or open close flow control valve whose closing element is a disc or conical plug which either rests against a horizontal sealing face to allow flow or is raised from a horizontal sealing face to allow flow my means of a perpendicular threaded stem.

GO - Gear Operated : Valve actuation via a gear set or gearbox that can multiply the torque or turning force applied according to the gear ratio through to the valve stem.

Graphite : Graphite is a flexible carbon material used for the manufacture of gaskets, seals and valve packing. Graphite gaskets may be flat sheet and may have metal inserts for added strength or Graphite can be used to impregnate PTFE to improve lubrication for steam solenoid valves.

Gravity Fed : A gravity fed solenoid valve means that the fluid is held in a tank or simply supplied from above without any pump pressure assistance. Typically these pressure from gravity fed systems are very low and require a zero rated solenoid valve. The higher the water or fluid column the higher the hydrostatic pressure, for every 10 meters height will increase the water pressure by 1 bar.

Grease Fitting : An adaptor or threaded fitting through which thick lubricant can be injected into and between moving parts.

Solenoid Valve Terminology H

Hand Wheel : A valve that is actuated by means of a hand operated wheel that is connected to a valve stem. The rotation of the wheel will in turn move or lift internal components within the valve body to allow or prevent the flow of media passing through.

Hard Facing : A process in which an alloy is welded or deposited onto a valve surface to increase wear resistance or corrosion.

Head : A head refers the the height of an open ended column of water or tank, which exerts pressure in direct relation to its height. See gravity fed systems.

Header : A header is typically a tank filled with fluid at a height above a measured point that exerts a pressure due to gravitational force. See gravity fed systems.

Heat Analysis ; Chemical analysis at the point prior to pouring at the foundry that measures the chemical composition of the liquid metal to be poured. will not include physical properties as metal is in liquid state.

Heat Treatment : The process of heating metal typically steel to a high temperature to change the internal structure of the compound to enhance strength or rigidity. Normally followed by a quick and controlled cooling process to set the material properties.

Horizontal Pattern : A horizontal pattern solenoid or process valve in which the connecting ends are in line with each other for installation into a straight horizontal pipe.

Hot Tapping : A process in which a pipe under pressure is cut into to provide a side outlet. Specialist equipment is used to prevent the escape of media under pressure whilst allowing for a hole to be drilled into the pipe and later secured by means of a shut off valve.

HNBR Seals : HNBR (Hydrogenated Nitrile Butadine Rubber) also known as HSN or Highly Saturated Nitrile Rubber has a high saturation of Butadiene carbon polymer giving higher thermal stability up to 150 degrees centigrade and improved chemical, dynamic loading and abrasion resistance over standard NBR. This is a rare seal to be found in a solenoid valve and only specialist solenoid valve suppliers would be able to offer this option.

HNBR has good resistance to motor oils, sour gas, amine oil mixtures, oxidised fuels, lubricating oils, mineral based hydraulic oil, animal and vegetable oil, diesel fuel, ozone, dilute acids and bases, new bio-oils.

HNBR has poor resistance to concentrated alkali's, esters, alkyl phosphate, ethers, halogenated solvents, ketone's, halogenated hydrocarbons, solvents and flames.

Huey Test : A stainless steel corrosion test for predicting inter-granular corrosion.

Hung Diaphragm : A hung diaphragm valve means that the sealing flexible elastomer diaphragm is attached to or hung from and directly controlled by an actuator or solenoid. As the diaphragm is hung or attached any movement from the actuator or control solenoid will direct move the diaphragm an will not rely on pressure differences. Hung diaphragm also known as kick pilot, forced pilot and assisted lift.

HWO - Hand Wheel Operated : A valve that is actuated by means of a hand operated wheel that is connected to a valve stem. The rotation of the wheel will in turn move or lift internal components within the valve body to allow or prevent the flow of media passing through.

Hydrant : A hydrant is an isolation valve mounted to one side of a pipeline to allow for the release of liquid media into a vessel or container for inspection or analysis.

Hydraulic : The use of liquid media such as oil or water under pressure to control a valve or cylinder. Hydraulic compressed fluid is used to transport energy along a pipe to provide mechanical force where needed.

Hydraulic Control Valve : A valve in which the closing disc, plug or diaphragm is moved or assisted by hydraulic force or differential pressure. See differential pressure.

Hydrostatic Test : A testing process in which a valve is completely filled with water (no air bubbles) and then pressure tested without actuation to provide a proof pressure test for the valve shell or pressure chamber.

Solenoid Valve Terminology I

IBBM - Iron Body Bronze Mounted : Typical valve terminology for a cast iron solenoid or process valve with bronze trim such as bronze seating face, bronze stem and or bronze bushings. Bronze is a far stronger structural material than Brass, offers very good heat resistance and reduced thermal expansion coefficients.

ID Inside Diameter : Inside diameter typically the internal diameter of a circular part such as a thread, fitting or valve port size.

Incoterms Trade Terms : INCOTERMS are sets of Three Character standard trade terms most commonly used in international contracts for the sale of goods, which must be clear at quotation.

  • EX Works EXW : The seller delivers the goods by putting them at the buyer's disposal at the sellers own premises or at some other named place. The seller is responsible for all costs and risks as far as the actual place of collection but has no obligation to load the goods on a carrier's vehicle nor to enter them to customs for export although he may agree to provide the buyer with information for customs clearance.
  • Carriage Paid To CPT : The seller delivers the goods to the carrier or another person nominated by the seller (by implication, unloaded from the seller's vehicle) at an agreed place (not the final destination) but bears all costs of transporting the goods to the final destination. The seller and buyer must agree on the place of delivery, where risk passes to the buyer, and the final destination which should both be specified precisely.
  • Delivered at Terminal DAT : The seller is responsible for moving the goods to the named terminal, which may be a quay at a port, a rail or air cargo terminal, a container yard, warehouse, or a precisely-identified place along a road or in a lorry park and for informing the buyer that the goods are available for him. Once the goods are unloaded the seller places them at the buyer's disposal on an agreed date or within an agreed period.
  • Delivered Duty Paid DDP : The seller delivers the goods when they are put at the disposal of the buyer, cleared for import on the arriving means of transport and ready for unloading at the named place of destination at an agreed time or within an agreed period. The seller bears all costs and risks to that point: he must clear goods both for export from country of export and for import and must pay any import charges including VAT and other taxes. Use of this term involves maximum responsibility for the seller. DDP should not be used if, as is often the case, the seller cannot obtain import clearance: if the buyer is to obtain import clearance, DAP should be used. The place of delivery need not be the buyer's premises, but it should be specified as exactly as possible.
  • Free on Board FOB : The seller delivers the goods on a ship nominated by the buyer at the named port of shipment or procures goods already delivered there. Risk of loss or damage passes when the goods are resting on or in the vessel, not when they are hanging from a crane or being handled over the ship's side. If goods are passed to a carrier before being loaded on a ship, as goods in containers are received by a carrier at an inland container terminal, FCA should be used.
  • Cost Insurance and Freight CIF : Cost Insurance and Freight CIF named port of destination Incoterms® 2010 - This term is to be used only when carriage is by sea or inland waterway. Risk of damage or loss passes once goods are on the vessel at the port of shipment or during carriage by sea if the transaction is one of a string. The seller delivers the goods on board the vessel at the port of destination or procures goods already aboard. The seller contracts for and pays costs for carriage to the port of destination and for insurance to cover the buyer's risk of damage or loss in carriage. The seller enters the goods to customs for export if applicable.
  • Free Carrier FCA : This term and not FOB should be used for containerised goods delivered to a carrier at an inland container terminal. The seller delivers goods to the carrier acting for the buyer at the seller's premises or another named place, which should be specified precisely. If delivery is at the seller's premises, goods are delivered when loaded on the vehicle provided by the buyer; elsewhere, goods are delivered on the seller's vehicle and ready for unloading on behalf of the buyer.
  • Carriage and Insurance Paid CIP : The seller delivers goods to a carrier or another person named by the seller, unloaded from the seller's vehicle, at a named place agreed between seller and buyer, and the seller is responsible for carriage, insurance and any other costs involved in conveying the goods to the final destination. The seller must obtain any export licence needed and enter the goods to customs for export and any transit arrangement. Unless by agreement with the buyer, insurance arranged by the seller need only be minimal: if the buyer wants more, the buyer is responsible for the cost of any extra insurance cover and must give the seller any extra information needed to obtain that cover. The place named in this Incoterm is not the final destination.
  • Delivered at Place DAP : The seller has no obligation to the buyer to insure goods either to or from that place, but may insure them to that place in his own interest. The seller bears all costs of carriage, insurance and anything else up to that place. This place should be specified exactly and the seller should ensure that his contract with the carrier includes it. If seller and buyer do not agree on the place, the seller decides it. The seller cannot recover cost of unloading at the named place without the buyer's agreement. If the buyer fails to take on the goods there, he is responsible for all costs resulting from warehousing, loss or damage from the agreed time of delivery.
  • Free Alongside Ship FAS : The seller delivers the goods when they are placed (on a quay or a barge) alongside the vessel nominated by the buyer at the named port of shipment. The place where cost and risk are transferred, and the time, should be identified as exactly as possible. The seller either delivers the goods alongside the ship or, if he is one of a string, procures goods from a previous owner in the string. For goods in containers, the seller often passes goods to a carrier at an inland terminal and then FCA should be used.
  • Cost and Freight CFR : As with CPT, CIP and CIF, the seller delivers goods on board a ship or vessel at the port of shipment or procures goods already so delivered aboard, and risk passes at the named port of destination but without unloading.The seller is responsible for all costs and freight required to bring goods to the named port of destination. He clears goods for export if applicable, but has no responsibility for import procedures or charges. He also pays for pre-shipment inspection if this is required by the country of export.

Incremental Seat Test : A leakage pressure test of a closed solenoid or process valve by incremental pressure increase steps.

Inlet Port : The inlet port of a valve into which media will flow from an upstream source, solenoid and process valves will have an inlet port marked as Inlet, IN, P, the number 1 or signified by a directional flow arrow on the base or side of the valve.

IP Ingress Protection Ratings : Coil IP ratings are the ingress protection rating for the coil, or when used with a correctly fitted electrical connector of similar of better IP rating. Sometimes referred to as Nema rating.

IP numbers explained first number from the IP rating denotes the dust tightness.

  • IP1 = Protected against objects bigger than Φ50mm i.e. a hand.
  • IP2 = Protected against objects bigger than Φ12.5mm i.e. a finger.
  • IP3 = Protected against objects bigger than Φ2.5mm i.e. a tool or screwdriver.
  • IP4 = Protected against objects bigger than Φ1.0mm i.e. a wire.IP4 = Protected against objects bigger than Φ1.0mm i.e. a wire.
  • IP5 = Protected against Dust.
  • IP6 = Dust tight.

IP numbers explained second digit the water ingress protection

  • IPx1 = Protected against vertically falling water droplets.
  • IPx2 = Protected against vertically falling water droplets up to 15° degrees inclination
  • IPx3 = Protected against vertically falling water droplets up to 60° degrees inclination.
  • IPx4 = Protected against splashing water from any direction.
  • IPx5 = Protected against water jets from any direction.
  • IPx6 = Protected against powerful water jets from any direction.
  • IPx7 = Protected against temporary immersion in water.
  • IPx8 = Protected against water submersion typically 3 meters depth

Typical examples of IP protection are IP54 = dust protection and water splashing from any direction or IP65 dust tight and protected from water jests from any direction. These ratings apply with correctly assembled valve and in instances with electrical connectors that the DIN connector is correctly fitted with gasket, correct cable gland and cable size security and entry position.

ISO9001:2008 UKAS (United Kingdom Accreditation Service) : The United Kingdom Accreditation Service is the national accreditation body for the UK, it is the British Government recognised accreditation body that assess's and certifies suppliers and organisations who provide certification, testing, inspection and or calibration services, that meet set criteria against internationally recognised standards. UKAS is the Accreditation Regulations 2009 (SI No 3155/2009) and the EU Regulation (EC) 765/2008 appointed national accreditation body and operates with the Government understanding through the Secretary of State for Business, Innovation and Skills.

There are many ISO9001 certification bodies in the UK, but if they do not show the UKAS Tick and Crown shown on the right, they are not an assessed and certified supplier against the ISO9001 standards. If a supplier cannot loose their certificate, then logic dictates that there is no guarentee that the supplier conforms to the quality standards required.

Solenoid Terminology K

Kick Pilot : Kick pilot solenoid valves are sometimes known as assisted lift valves. In this instance the diaphragm or piston is attached to the armature as assure valve operation for low pressures "Kick" and also includes an internal pressure "pilot" to give servo pressure assistance for higher system pressures.

Solenoid Valve Terminology L

Laminar Flow : The flow of a viscous fluid in which the fluid moves in parallel layers with a fixed velocity gradient from the centre-line to the containing walls of the pipe.

Latching : Latching sometimes referred to as Bi-stable is a solenoid valve that can stay in either open or closed position by means of a semi permanent magnet. A short DC electrical pulse typically up to 50 Milliseconds is applied to energise the magnet which will lift and hold the armature even when no electrical power is supplied. To release the magnetic field or hold a second similar electrical pulse is applied with reverse polarity to neutralise the magnetic hold and release the armature back to its fail safe position.

Leakage Class : Solenoid Control Valves are designed to open, close and divert the flow of media. In most cases the valve will pass small amounts of fluid or gas media over time depending on the application parameters such as pressure, temperature, media etc. Valves can be have a leakage class rating from Class I, II, III, IV, V and VI.

Leakage Class Designation

Maximum Leakage Allowable

Test Medium

Test Pressure

Testing Procedures Required for Establishing Rating





No test required


0.5% of rated capacity

Air or water at 50 - 125o F (10 - 52oC)

45 to 60 psig or maximum operating differential whichever is lower

45 to 60 psig or maximum operating differential whichever is lower


0.1% of rated capacity

As above

As above

As above


0.01% of rated capacity

As above

As above

As above


0.0005 ml per minute of water per inch of port diameter per psi differential

Water at 10 to 52oC or 50 to125oF

Maximum service pressure drop across valve plug not to exceed ANSI body rating

Maximum service pressure drop across valve plug not to exceed ANSI body rating


Not to exceed amounts shown in the table above

Air or nitrogen at 10 to 52oC or 50 to125oF

50 psig or max rated differential pressure across valve plug whichever is lower

Actuator should be adjusted to operating conditions specified with full normal closing thrust applied to valve plug seat

Length : Length or measurements of physical size and normally used to ensure the valve being used will fit into the application. The most common measurement of either a threaded or flanged valve will be the length to determine if the valve will fit into the existing pipework. Length is typically given in millimetres (mm), centimetres (cm) or inches(").

  • 1" inch = 25.4mm
  • 1/16" inch = 1.5875mm
  • 1 foot = 0.305 meters = 12 inches
  • 1 meter = 100 centimetres = 1000 mm
  • 1 cm = 10 mm
  • 1 mile = 1.609 kilometre = 1609 meters/li>

Lever Operated : An operating lever or mechanical arm for the mechanical operation of a process valve, or as a manual over ride for a solenoid valve to manually open or close the valve, manual reset solenoid valve system for a gas safety shut off solenoid valve to prevent auto rest upon electrical power supply.

Life Expectancy : The life expectancy of a solenoid valve depends more on the application rather than the design parameters of the solenoid control valve. Temperature, duty cycle, moving positions, frequency of operation, media cleanliness, voltage tolerances will affect the valve life. Typical valve expectancy will range from 1,000,000 cycles up to 10,000,000 cycles for pneumatic valves>

Lifting Lugs : Lugs or eyelets built into a heavy solenoid or process valve to allow for lifting, transportation and positioning without damaging to the valve body. Typically found on large bore DN300 to DN1000+ solenoid valves, pressure reducing valves, pressure sustaining valves and pressure relief safety valves.

Limit Switch : A volt free electrical switch fitted to a solenoid or process valve that can provide an electrical signal to a remote control or observation control panel to indicate the valve fully open or fully closed position.

Line : A line pipeline or hose through which media will travel, used for the transportation of gases or fluids.

Lip Seal : A "U" shaped round seal as found in a pressure reducing valve, pressure sustaining valve, pilot float valve, pressure relief valve. Offers improved sealing and service life compared to a standard O Ring.

LPI - Liquid Penetration Inspection : A method of detecting surface cracks or imperfections in valve castings and flange welds by means of a coloured dye.

Locking Device : A mechanical device that typically incorporates a padlock to prevent the manual operation or unauthorised actuation of a valve in a process system.

LNG - Liquefied Natural Gas : Natural Gas held as in liquid form under pressure and a cryogenic low temperature, as a liquid the LNG gas requires substantially less volume and can be transported in liquid volume by pipe, lorry, canister or stored to await re-gasification (liquid back to gas).

LPG - Liquid Petroleum Gas : Butane or Propane gas held in liquid form under low pressure, as a liquid the LPG gas requires substantially less volume and can be transported in liquid volume by pipe, lorry, canister or stored to await re gasification (liquid back to gas).

LPG - Liquid Petroleum Gas : Butane or Propane gas held in liquid form under low pressure, as a liquid the LPG gas requires substantially less volume and can be transported in liquid volume by pipe, lorry, canister or stored to await re gasification (liquid back to gas).

Solenoid Terminology M

Male Thread : A male thread is an external thread OD Outside Diameter, ie. threads on the outside. A male thread (OD) will screw into a female thread (ID)

Manifold : A manifold is a system in which a common inlet pipe or media chamber will have multiple outlets. A manifold mount or sub base mount 2/2 or 3/2 way solenoid valve system will have a common inlet with several solenoid controlled outlets.

Material Test Report : A material certificate (3.1b) produced by the steel or stainless steel material manufacturer providing the chemical and mechanical properties of the material within a specific production batch.

Metal to Metal Seal : A metal to metal seat and sealing face within a valve without elastomer or synthetic seal materials. Typically found in special application solenoid valves, aggressive media and corrosion resistant valves, high temperature valves and thick glutinous media valves.

MAOP - Max Allowed Operating Pressure : MAOP or maximum allowed operating pressure or maximum working pressure or actuation pressure of a valve.

Manifold Valve : A manifold or sub base valve is a single shared block with either single inlet with two or more solenoid valves sharing the common inlet and having a solenoid controlled outlet at every station / solenoid.

Manual Over Ride : A manual over ride is a mechanical component attached to a valve such as a lever, Knob, screw or button that allows an engineer or machine operator to "manually" actuate or mechanically "over ride" a valve from its fail safe position. For example a 2/2 way normally closed valve can be manually opened without the need for any electrical supply. This is very helpful for valve commissioning or during power failure situations.

Maximum Operating Voltage : The Max operating voltage that can be applied to the solenoid coil, typically +10% from the stated voltage. For example 24vDC MOV would be 24+10% = 26.4 volts.

Maximum Operating Pressure Differential. (MOPD) : The maximum operating pressure differential is the maximum allowable or design pressure difference ΔP between the inlet and outlet ports when the valve can still function correctly. For example if the MOPD is 10 bar with an inlet pressure of 10 bar and outlet to atmosphere (0 bar) then the pressure difference is 10 bar.

Media : Media refers the the liquid or gas to be controlled such as air, water, steam, oil, acid, alkali, natural gas, ozone, vacuum, sea water, glycol, petrol, diesel, aviation fuel etc.

Media Temperature : Solenoid valve media temperature refers typically to the maximum temperature °C or °F of the liquid or gaseous media being controlled by the solenoid valve. For example a general purpose solenoid valve with an NBR seal may have a maximum design media temperature of+80°C, where as a steam rated solenoid valve would have a maximum media temperature design limit of +185°C.

MGA Controls Operator. : MGA controlled operator is a manually operated gear system for valve actuation, typically by means of a hand wheel.

MGO - Manual Gear Operator : MGO Manual Gear Operator is a manually operated gear system for valve actuation, typically by means of a hand wheel.

Mill Certificate : Certification of chemical analysis and physical properties of a manufactured batch of steel or stainless steel supplied by the steel mill. Mills certifications typically required for the valve shell or pressure containing parts. Mill certs are available from most mills during production offering full traceability but cannot be back dated or supplied at a later date.

Mill Tests : Mill test certification provided from a steel or stainless steel mill or foundry that offer heat, chemical and physical analysis. May on occasion include or be available with impact test reports for the same mill test report.

Minimum Operating Voltage. (MOV) : The Min operating voltage that can be applied to the solenoid coil so that the solenoid valve will still function correctly within is MOPD (Maximum Operating Pressure Differential), typically -10% from the stated voltage. For example 240vAC MOV would be 240-10% = 216 volts.

Minimum Operating Pressure Differential. (MOPD) : Minimum operating pressure differential MOPD is the minimum pressure difference between inlet and outlet ports ΔP required for the valve to function correctly. A valve with a Minimum ΔP of 0.5 bar means that the inlet pressure MUST BE higher than the outlet pressure by at least 0.5 bar or 7 psi for the valve to fully open or close correctly.

MO - Motor Operated : MO or motor operated valve is a ball, gate, globe or butterfly valve who's method of actuation is by means of an electric motor, typically via a reducing gear box.

MOE - Modulus Of Elasticity : Modulus of elasticity is a coefficient of elasticity being the ratio of force (stress) applied against structural deformation (strain).

Mounting Position : The mounting position of a valve relates to the horizontal or vertical position of the controlling mechanism. For example most solenoid valves required mounting vertically, which means that the solenoid coil must be upright or vertical.

MPI - Magnetic Particle Inspection : A test procedure utilising iron filings and a magnetic field to detect imperfections within a metal casting. Imperfections will generate inconsistent or abnormal magnetic fields which are visibility highlighted by the iron filings or particles.

MSS - Manufacturers Standardisation Society : Manufacturers standardisation society is a technical association for the valve and fittings industry who publish written standards and advisory best practices.

MWP - Maximum working Pressure : MWP is the maximum working pressure for a valve typically measured in PSI or BAR. Maximum working pressure can also be given as a Classes, within temperature limits -20ºF to +100ºF.

Solenoid Valve Terminology N

NACE - National Association of Corrosion Engineers. : NACE are an association of technical engineers that write and publish papers relating to all aspects of corrosion and have written specific valve standards for valve corrosion in particular for valves for sour gas service.

NBR seals : NBR is an elastomer seal material (Nitrile Buna Rubber) or referred to as Butadiene Acrylonitrile which is found in most valves as a standard or general purpose sealing material. NBR will work up to +80°C possibly +100°C for a short time. NBR withstands ageing well with good abrasion resistance but poor resistance to sunlight (UV rays). NBR has good resistance to Aliphatic Hydrocarbons, Petroleum, Fuels, Mineral Oil, Vegetable and Hydraulic Oil, Alcohol and many Acids. NBR has poor resistance to Ozone, Acetone, Methyl ethyl Ketone, Chlorinated Hydrocarbons, Ethers and Esters.

Needle Valve : A needle valve is typically a small compact valve with an internal needle or tapered point that can move into or away from a small sealing orifice offering variable flow control for metering applications.

NEMA - National electrical Manufacturers Association : NEMA classification which is a set of guidelines for electrical equipment, such as degrees of ingress and ATEX protection as used for solenoid valves. Can be converted to IP65 see IP protection.

  • Nema 1 Enclosures constructed for indoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment and to provide a degree of protection against falling dirt. Can be converted to IP10.
  • Nema 2 Enclosures constructed for indoor used to provide a degree of protection to personnel against incidental contact with the enclosed equipment, to provide a degree of protection against falling dirt, and to provide a degree of protection against dripping and light splashing of liquids. Can be converted to IP11
  • Nema 3 Enclosures constructed for either indoor or outdoor used to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to proved a degree of protection against falling dirt, rain, sleet, snow, and windblown dust; and that will undamaged by external formation of ice on the enclosure. Can be converted to IP54.
  • Nema 3R Enclosures constructed for either indoor or outdoor used to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt, rain, sleet, and snow; and that will be undamaged by external formation of ice on the enclosure. Can be converted to IP14.
  • Nema 3S Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt, rain, sleet, snow, and windblown dust; and in which the external mechanism(s) remain operable when ice laden. Can be converted to IP54.
  • Nema 4 Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt, rain, sleet, snow, windblown dust, splashing water, and hose-directed water; and that will be undamaged by the external formation of ice on the enclosure. Can be converted to IP56.
  • Nema 4X Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt, rain, sleet, snow, windblown dust, splashing water, hose-directed water, and corrosion; and that will be undamaged by thee external formation of ice on the enclosure. Can be converted to IP56.
  • Nema 5 Enclosures constructed for indoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt; against settling airborne dust, lint, fibres, and flyings; and to provide a degree of protection against dripping and light splashing of liquids. Can be converted to IP52.
  • Nema 6 Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt; against hose-directed water and the entry of water during occasional temporary submersion at a limited depth; and that will be undamaged by the external formation of ice on the enclosure. Can be converted to IP67.
  • Nema 6P Enclosures constructed for either indoor or outdoor use to provide a degree of protection to the personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt; against hose-directed water and the entry of water during prolonged submersion at a limited depth; and that will be undamaged by the external formation of ice on the enclosure. Can be converted to IP67.
  • Nema 12 Enclosures constructed (without knock-outs) for indoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt; against circulating dust, lint, fibres, and flying; and against dripping and light splashing of liquids. Can be converted to IP52.
  • Nema 12K Enclosures constructed (without knock-outs) for indoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt; against circulating dust, lint, fibres, and flying; and against dripping and light splashing of liquids. Can be converted to IP52.
  • Nema 13 Enclosures constructed for indoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt; against circulating dust, lint, fibres, and flying's; and against the spraying, splashing, and seepage of water, oil, and non-corrosive coolants. Can be converted to IP54.

Non Destructive Testing : A valve pressure, function or flow test that does not damage or destroy the valve being tested.

Normally Closed Solenoid Valve : Normally closed refers to the normal state of the solenoid valve in the fail safe (electrical power off) position of the valve as Closed. So without power the valve is "normally closed" preventing the flow of media through the valve.

Normally Open Solenoid Valve : Normally open refers to the normal state of the solenoid valve in the fail-safe (electrical power off) position of the valve as Open. So without power the valve is "normally open " allowing the flow of media through the valve.

Norsok Standard : NORSOK standards are used by the Norwegian Petroleum Industry to unsure a cost effective yet prudent safety levels for all offshore and onshore petroleum industries and processes.

NPS - Nominal Pipe Size : Indicates the port size of a valve which can be used for matching valves sizes connection onto other pipelines or valves.

NPT - National Pipe Tapered Thread : NPT thread is an American standard tapered thread standard.

NRS - Non Rising Stem : A typically multi turn valve those stem is threaded into the valve gate, the stem will turn but not rise from the valve body. Non rising stem threads are exposed to the media inside the valve body.

Solenoid Valve Terminology O

OCMA - Oil Companies Materials Association : Association of British Oil Companies that have written standards for fire safe testing of valves.

OD - Outside Diameter : OD or outside diameter is the measured external diameter of a circular pipe or tube.

Opening Time : The opening time of a valve is the time required typically from 20 milliseconds to 5 seconds for a valve to move from the fully closed position to the fully open position. Note that solenoid valves open much faster than actuated valves.

Operation : Solenoid valve operation is the way the solenoid valve is designed to operate. This can be direct acting, assisted lift or servo assisted.

Operating Time : The measured time required for a valve to move from the fully closed position into the fully open position, or the time for an actuated valve to move from one extreme position into the fully opposite position.

Operator : A mechanical device that converts electrical energy into mechanical motion, sometimes referred to as a solenoid armature. An operator can also be a device that converts pneumatic, hydraulic or electrical energy into mechanical force or motion.

Orifice size : The orifice of a solenoid valve is given as the internal diameter in mm or inches of the valve sealing face where the media passes through and is controlled by a piston or diaphragm sealing against it. A valve with a 25mm orifice will typically offer high flow of media than a valve with a smaller orifice of say 20mm.>

O Ring : An O ring is a circular round sealing ring typically an NBR, FKM or EPDM elastomer seal that has a circular cross section.

Oxygen cleaned : See degreased

Solenoid Valve terminology P

Parallel Thread : A parallel thread is a straight thread sealing is by O ring or bonded washer between the two flat surfaces of the male threaded fitting being screwed in and the female threaded flat face.

Pilot Assisted : See pressure assisted

Pin Hole : A small hole typically though the thickest part of the valve body casting or just below the surface caused by gases trapped in the molten metal during cooling.

Pinion Shaft : An external gear drive shaft typically with a hand wheel or actuator connected to it, that will drive an internal reduction gear for valve actuation.

Plastic : A generic term for a non metallic material such as PVC, PP, PVDF, Nylon, Delrin or PTFE used in the construction of water and aggressive media solenoid valves and sometimes used as a protective coating for other valve types.

Plug : An electrical connector that allows for an electric cable or power supply to be easily connected to or removed from an electrically actuated valve or controller. Sometimes referred to as DIN 43650 electrical connectors.

Plunger : The solenoid plunger sometimes referred to as the armature is the magnetic stainless steel part that moves when the solenoid coil is activated, which in turn either directly or indirectly changes the sate of the solenoid valve.

PMI - Positive Material Identification : Positive material identification is a system for checking the identity of a valve material.

Pneumatic : Pneumatic means an air or gas media that is compressed and piped to an air operated system or valve. Pneumatic typically means air.

Pneumatic Test : A pneumatic test is typically a valve tested with compressed clean dry air. Typically valves are tested in the closed position to ensure leak tightness and can be tested in both open and closed positions to test the valve is functioning and working correctly.

Porosity : Porosity is a defect in valve body castings caused by gas bubbles or open spaces (voids) in the metal, main the valve body porous.

Port : A port is the connecting point of a valve, a valve with two ports will have one inlet and one outlet, a valve with three ports will be a diverting valve diverting flow to one of two pipelines. A port can be threaded, flanged or weld end.

Port Size : Solenoid valve port or connection size are most commonly measured by thread or flange connection.

Position Indicator : A position indicator is typically a visual position flag or grommet within a clear protective window that gives visual indication of the mechanical open or closed position of a valve.

Position Switches : Position switches are used to provide a volt free mechanical or proximity electrical switch that is triggered when the valve is in the open or closed position, for remote confirmation of valve position. An open position or signal feedback switch will confirm by switch contact the valve open position, a closed position switch will confirm by switch contact the valve closed position. Either one or both can be used with various solenoid or coaxial valves.

Power Ratings : Power rating typically refers to the electrical supply power rating or Watts (watts = volts multiplied by amperes). A transformer or power supply may have a Amperes rating. For example a power rating of 1 Amp would be sufficient to power 1 220vAC solenoid valve with a 17 Watt coil, as the current consumption would be Amps = 17watt/ 220volt = 0.077 Amps, but when used with 12vDC 15 watts would give a valve power consumption of 17watt / 12vdc = 1.1466 Amps being more than the available power (current) supply. See coil power ratings.

Pressure : Pressure is measured in terms of units of force against area, for example 15 PSI or 15 pounds force on every every square inch. Another measurement of pressure commonly used is Bar, 1 bar = 1 atmosphere or 14.71 PSI so 10 bar would equate to 147.1 psi, another term kg/cm2 or kilograms force per square centimetre 1 Kg/cm²=1.0197 Bar but safe enough to assume bar = kg/cm² . Pressures and vacuum can be easily converted from Torr, mmHGa, PSI, Hgv, Atm, H2o, Kg/cm2, kPa, Bar and mBar.

Pressure Assisted : Pressure assisted also known as pilot operated means that the pressure difference across the valve is being used to open or close the valve. Pressure difference is the difference between the inlet pressure to the valve and the outlet pressure from the valve, known as ΔP.

Pressure Differential : Pressure differential is required for some types of solenoid valves, such as pilot operated valves servo assisted valves, floating diaphragm valves and pressure assisted valves. Pressure differential is the pressure difference between the inlet and outlet ports of the valve. For example a valve with 2 bar inlet and open ended to atmosphere would have a pressure differential (difference) of 2 bar but small gravity fed solenoid operated or solenoid actuated valves piped into closed loop systems would have a low pressure differential.

  • 1 bar = 14.71 PSI
  • 1 bar = 100 kPa (kilo-pascal)
  • 1 PSI = 6.9 KPa
  • 1 Kg/cm² = 0.98 bar
  • 1 atmosphere = 1.013 bar
  • 1mm Mercury = 1.33 mbar
  • 1 Ton /in² = 154 bar

Pressure Drop : Pressure drop is the difference in pressure between two points. A pressure drop of a valve is the pressure difference between inlet and outlet ports. Pressure drop will occur along any pipe or through any valve as is caused by friction, restrictions and change in flow direction.

Pressure Gauge : A pressure gauge is a pressure measurement device that indicates the pressure at the point at which it is connected to the pipeline system. Pressure gauges are typically threaded at the base or rear and can be glycerine filled to prevent the pressure indicator needle vibration.

Pressure Rating : Pressure rating is the maximum allowable working pressure the equipment is designed to operate. This can be a minimum or maximum pressure rating.

Pressure Switch : An electrical volt free switch connected into a pipeline that will open or close according to its setting and the pipeline pressure. Used for simple ON/OFF control and monitoring of pipeline pressures.

Proof Pressure : a liquid or water hydrostatic pressure test typically 150% of rated maximum working pressure applied to a valve in the closed position to test the structural integrity of the pressure bearing shell or valve body.

Proximity Switch : A proximity switch is a volt free valve position indication switch that utilises magnetic field disruption or something metallic close to its "Proximity"to switch. For example an open proximity switch in an angle seat piston valve will react (switch and make circuit) when the valve piston lifts open and the metal stem is close to or within the proximity of the switch. A control panel will know by break or make electrical circuit if a valve is mechanically fully OPEN or CLOSED.

PRV - Pressure Reducing Valve : Pressure reducing valves are designed to reduce and maintain a pre-set outlet pressure regardless up inlet or upstream pressure variations caused by other process demands, valve or pump changes. Pressure reducing valves are available in direct acting and pilot operated operation.

PSI - Pounds per Square Inch Pressure : PSI is a measurement of applied pressure measured in pound force per square inch. For example one atmosphere is 14.71 psi being 14.71 pounds force applied to each square inch so a pressure vessel with 10 square inches of surface area would have an applied force measured at 10 x 14.71 = 147.1 pounds of force or 66.86 Kg.

PTFE seal : PTFE or Polytetrafluoroethylene) is also known as Teflon®, Teflon is a trade mark of Dupont. PTFE offers excellent chemical resistance to most liquids and temperatures up to +230°C and down to -200°C for cryogenic applications. PTFE has good resistance to most liquids and gases. PTFE has poor sealing characteristics as it is a hard material without the elasticity of NBR, EPDM, FKM, which will cause leakage or sealing difficulties if the media being controlled is not clean.

PU220â„¢ : PU220® is a zero rated 2/2 way brass solenoid valve and is also a registered class 9 trade mark number 2456842 for Connexion Developments Ltd.

PU225â„¢ : PU225® is a pressure assisted 2/2 way brass solenoid valve and is a registered class 9 trade mark number 2456841 for Connexion Developments Ltd.

Pump Control Valve : A specialised check valve to control flow and prevent cavitation and water hammer in or from pumps and liquid flow lines.

Solenoid Valve Terminology R

Radiographic Inspection : Radiographic inspection is the X ray analysis for checking welds, metal castings and metallic fabricated parts for flaws, cracks and potential weaknesses.

Rectified : A rectified coil or connector will typically include a bridge rectified or full bridge rectified circuit that will convert AC 50/60Hz alternating current input into DC direct current output.

Rectified Coil : A rectified coil converts the AC (alternating current) 50/60Hz into DC (direct current) typically by an internal full bridge rectified circuit to allow for a DC coil to be used. DC coils generally offer quieter operation without the 50/60Hz Buzz normally associated with AC applications, but typically can offer a reduced pressure range in accordance with DC valve pressure range if used for direct acting or assisted lift zero rated solenoid valves.

Reduced Bore : A solenoid valve or gate, ball or globe valve those port or connecting point is smaller than the pipeline internal or bore diameter, hence reduced bore.

Regulator : A pressure control valve that automatically regulates, reduces and controls a pre-set sometimes manually adjustable outlet pressure, regardless of upstream or inlet pressure increases or changes.

Relief Valve : A safety pressure release valve designed to automatically release fluid pressure to protect pressure bearing equipment from over pressure damage. Regulations ensure that pressure relief valves are fitted to all pressure vessels to ensure that their maximum design pressure is not exceeded.

Relieving : A relieving valve or pressure regulator will vent excess downstream system pressure if the pressure exceeds the set pressure or the pressure setting is reduced. A relieving air pressure regulator will vent excess downstream air pressure externally.

Response Time : The response time is the time required by a solenoid valve to completely change its state from Open position to Closed position or visa versa. Typical response times are around 20 to 50 milliseconds (0.05 seconds) for miniature solenoid valves up to 1/2" and from 100 - 5000 milliseconds (0.1 to 5 seconds) for larger valves. Larger valves operate more slowly to avoid the effects of water hammer and internal damage.

RF - Raised Face : A raised area on the face of a flange where the sealing gasket will fit. The reduced sealing face means that a higher applied pressure is applied to a smaller surface area and any minor damage to the flange face edges due to transportation or installation will not inhibit sealing.

Rising Stem : A gate or globe valve whose stem will rise out of the valve body when the valve is opened. Typically the stem is not in contact with the media passing through the valve.

RO Water : RO or reverse osmosis water is a water purification process where water is forced through semi permeable membranes which remove between 90% to 99% of tap water impurities, producing water that is free from minerals and other impurities.

Rockwell Hardness Number : A measurement of metal hardness by a Rockwell Hardness Tester. Rockwell scale B for soft metals, Rockwell scale C for hard metals.

Rohs Compliance Definition : ROHS definition and aim is to restrict certain dangerous substances commonly used in electronic and electronic equipment. An RoHS compliant component or product is tested for the presence of Lead (Pb), Cadmium (Cd), Mercury (Hg), Hexavalent Chromium (Hex-Cr), Polybrominated Biphenyls (PBB), and Polybrominated Diphenyl Ethers (PBDE). For Cadmium and Hexavalent chromium, there must be less than 0.01% of the substance by weight, for Lead, PBB, and PBDE there must be no more than 0.1% of the material, when calculated by weight. Any RoHS compliant component must have 100 parts per million or less of mercury and the mercury must not have been intentionally added to the product or component. In the EU, some military and medical equipment are exempt from RoHS compliance.

RPM - Revolutions Per Minute : RPM or revolutions per minute is a measure of rotating speed of a shaft or wheel given as complete turns over a one minute measured time interval.

RTJ - Ring Type Joint : A ring type joint or flange connection with metal metal sealing that are used on high pressure applications such as the gas and oil exploration and production. R.T.J joints excel in sealing for high pressure pipelines and fittings.

Rupture Disc : A thin metal disc on a pressurised system designed to break or rupture at a specific pressure, much like a pressure relief valve but in this case will vent all pressure and will need to be replaced if ruptured.

Solenoid Valve Terminology S

Safety Valve : A mechanical valve designed to quickly release system over pressure to prevent pressurised systems from exceeding their maximum design pressure. Safety pressure valves or pressure relief valves typically stay closed and will only open when system pressures reach or get close too the maximum pressure setting, at which point the pressure release valve will quickly open. When pressure return back below the safe pressure the safety valve will slowly close.

Schedule : Schedule is a measurement of pipe thickness. The higher the schedule number the thicker the pipe material.

Screw Down Stop Valve : A valve those piston or gate is either lifted from an sealing orifice to allow flow pressed against a sealing orifice to prevent flow through a valve where the gate or piston is attached to a threaded stem. The stem is rotated by an external hand wheel or lever to operate the stop valve.

Screwed Ends : A solenoid valve, gate valve, globe valve or piston control valve whose connecting ends are threaded. Threaded valves are typically female thread (internal thread) and are commonly either BSP or NPT thread. See threads for more information and guidance.

Seals : Seals relates to the sealing materials used through the valve, including the diaphragm, body O Ring. baseplate O ring, stem seals and armature seals used. Typical seals used are NBR, FKM (Viton®), EPDM or PTFE (Teflon®).

Seat : A valve seat is the sealing face inside the valve where the sealing diaphragm, piston or gate will rest and seal against when the valve is closed preventing flow.

Self Relieving : A self relieving valve will vent excess pressure into the downstream or upstream pipeline.

Separator : A separator is a tank or vessel used to separate fluids from gases, sometimes used in crude oil separating systems and air filtration equipment.

Servo Assisted : See pressure assisted. Servo assisted valve means pressure assisted also known as pilot assisted. The pressure difference between the inlet port and outlet port of the valve or pressure differential (Δp), is controlled by a solenoid via an internal servo circuit to move the main sealing piston or diaphragm. In this instance the main sealing piston or diaphragm is not connected to anything and is simply "floating" according to the pressure differences across it.

Shading Ring : A shading ring is either situated on top of the solenoid armature or inside the top of the core tube. Typically shading rings are copper, but can be silver for pure water applications or even Aluminium or Ammonia applications. The function of the shading ring is to act as a stop area of an AC (alternating current) and to act as a mini rectifier.

Shako â„¢ : Solenoid and pneumatic valve and component manufacturing company in Taiwan. Shako® is also a class 9 registered trade mark number 2456840 for Connexion Developments Ltd.

Shut Off Valve : A shut off valve is an fully Open or fully Closed isolation valve that only has these two positions and cannot be used as a midway or part open or part closed throttling valve. An ideal example of a shut off valve is a solenoid valve with two positions.

Short Pattern Valve : A short pattern valve is a solenoid or other control valve whose length port to port is less than the typical standard.

Silicone Free : Silicone free means that the valve has no trace of silicone either internally or externally. Silicone free valves are used in Paint spraying environments where the presence of any silicone would serious hinder the painting processes.

Silicone Seals : Silicone seals are available with some leading solenoid valve suppliers, it is a soft rubber withstands high temperatures beyond 150 degrees centigrade and low temperatures down to -60 degrees centigrade, but can harden and become brittle when heated with air. Silicone has good resistance to Oil but not diesel, solvents, aniline alcohol, dilute acids or bases, benzene, toluene, gasoline. Silicone has poor resistance to Hot air, steam over 150 C, strong acids and bases and of course Diesel fuel.

Slurry Service : A thick media with solid particles suspended within a fluid. Typical examples would be ceramic slurry, effluent treatment works slurry and coal water slurry.

SNG - Synthetic Natural Gas : Synthetic Natural Gas SNG is a substitute natural gas or synthetic fuel gas that is produced from lignite coal and oil shale fossil fuels or biofuels (bio-SNG) or from renewable electrical energy.

Socket Weld End : A valve or fitting whose end connections have been suitably prepared for socket welding to a pipeline or control valve with the same correctly prepared end fittings.

Sour Gas : Sour gas is a natural gas with a high content of Hydrogen Sulphide (Hâ‚‚S). Natural gas is considered to be sour if there are more than 5.7 milligrams of Hâ‚‚S per cubic meter or 4 parts per million by volume.

Solenoid Valve : An electrically actuated electromagnetic control valve for the On/Off open/closed control of liquid or gas media. Solenoid valves offer fast reliable on/off and diverting control for any clean media and are available in brass, bronze, 304 and 316 stainless steel, cast steel, cast iron, ductile iron and various types of synthetic plastic materials to cope with most air, water, gas, liquid, fluid, oil, vacuum, steam, acid or alkali media from cryogenic applications at -200°C to +250°C for pressure ranging from full vacuum up to +500 bar or more, in sizes ranging from M5 up to DN1400 flange.

Specification : Specification of a valve can mean the technical and or physical characteristics of a valve including its function, operation, dimensions, materials of construction, pressure and temperature range, port connection size and type. Alternatively a valve that has been specified will mean the valve make and model has been designed into the system and thus is "specified" and is the only valve that can be installed.

Specific Gravity : Specific gravity the ratio of the weight of fluid compared to the weight of an equal volume of water, or the weight of gas compared to the same volume weight and pressure of air.

Spring Return : Spring return means that there is a mechanical spring within the valve structure that will push the valve back to its default position. For example a spring return normally closed solenoid valve will automatically return to the closed position at rest.

SPU225â„¢ : SPU225® is a pressure assisted 2/2 way stainless steel solenoid valve and is a class 9 registered trade mark number 2456839 for Connexion Developments Ltd.

Stainless Steel : Stainless steel is an iron alloy with a minimum 10.5% of added Chromium and 8% Nickel depending on the grade of stainless steel which prevent the metal from oxidisation in air.

  • 18-8: 300 range of stainless steel with about 18% Chromium and 8% Nickel. 18-8 typically includes 302, 302HQ, 303, 304, 384 and XM7 and other similar grades of similar composition.
  • 304: Type 304 stainless is an austentic steel with a minimum 18% Chromium and 8% Nickel combined with 0.08% Carbon. A non magnetic steel which cannot be heat treated but must be cold worked to gain higher tensile strength. 304 will resist most oxidising acids and ordinary rusting but may tarnish. It is immune to food stuffs, sterilising solutions, most organic chemicals, dyestuffs, and inorganic chemicals. Typical stainless 304 analysis Carbon 0.08% max, Manganese 2% max, Phosphorus 0.045% max, Sulphur 0.03% max, Silicone 1% max, Chromium 18% to 20% and Nickel 8 to 10.5%.
  • 316: Type 316 stainless is an austentic steel with minimum 16-18% Chromium, 10-14% Nickel, 0.08% Carbon and 3% max Molybdenum. A non magnetic steel which cannot be heat treated but must be cold worked to gain higher tensile strength. The Molybdenum increases corrosion resistance and can withstand attack from most industrial chemicals and solvents and inhibits pitting caused by Chlorides, Sodium and calcium brines, hypochorite solutions, phosphoric acids, sulphite liquors and sulphuric acids. Typical stainless 316 analysis Carbon 0.08% max, Manganese 2% max, Phosphorus 0.045% max, Sulphur 0.03% max, Silicon 1% max, Chromium 16 to 18% and Nickel 10 to 14%, Molybdenum 2 to 3%.
  • Type 301 contains less chromium and nickel than 302 for more work hardening.
  • Type 302 is the basic type of the 300 series, 18% chromium, 8% nickel group. It is the renowned 18-8 Stainless and is the most widely used of the chromium nickel stainless and heat resisting steels.
  • Type 303 contains added phosphorus and sulphur for better machining characteristics.Corrosion resistance is slightly less than 302 or 304.
  • Type 303Se contains Se and P added to improve machine-ability.
  • Type 305 has increased nickel to lower work hardening properties.
  • Type 309 and 309S have added chromium and nickel for more corrosion resistance and high temperature scaling resistance. 309S contains less carbon to minimize carbide precipitation.
  • Type 310 and 310S have higher nickel content than 309 and 309S to further increase scaling resistance. 310S contains less carbon than 310 to minimize carbide precipitation.
  • Type 321 contains titanium to tie up the carbon and avoid chromium carbide precipitation in welding.
  • Type 330 ultra high nickel content provides best corrosion resistance to most furnace atmospheres. This grade has low coefficient of expansion, excellent ductility and high strength.
  • Type 347 and 348 have columbium tantalum added to tie up the carbon and avoid chromium carbide precipitation in welding. Use for temperatures from 800°F to 1650 degrees F.
  • Type 630SS or 630 stainless steel is a derivative of 304 stainless steel, typically used for drinking water applications as this grade of stainless is unlike to alter the water taste. Chemical composition: Max 0.07% C, 1% Max Si, 1% Max Mn, 0.04% Max P, 0.03% Max S, 15 to 17.5% Cr, 3% min N, 3 to 5% Cu and Nb + Ta 0.15 to 0.45%.
  • Type 405 contains 12% chromium with aluminium added to prevent hardening.
  • Type 430 is the basic type in the ferritic group, possessing good ductility and excellent resistance to atmospheric corrosion. Its scaling resistance is higher than 302 in intermittent service, somewhat lower in continuous use.
  • Type 430F and 430Se have sulphur and selenium (respectively) added for increased machine-ability.
  • Type 442 has added chromium for improved resistance to scaling.
  • Type 446 has still higher chromium content (27%) for added scaling resistance and is highest of the standard straight chromium types. Alloys with over 30% chromium become too brittle to process.
  • Type 410 is the basic Martensitic type. It is the general purpose corrosion and heat resisting chromium stainless steel. It can be hardened by thermal treatment to a wide range of mechanical properties. It can be annealed soft for cold drawing and forming. This grade is always magnetic.
  • Type 403 is a special high quality steel made for blades and buckets for steam turbine and jetengine compressors. This grade is eminently suited for very highly stressed parts. This material is magnetic in all conditions.
  • Type 416 and 416Se are modifications of Type 410, being the free machining, non seizing, non galling alloys. These properties are obtained by the addition of sulphur or selenium to Type 410. This is a heat treatable grade with corrosion resistance and other characteristics closely approaching those of Type 410.
  • Type 420 is a chromium stainless steel capable of heat treatment to a maximum hardness of approximately 500 Brinell. It has a maximum corrosion resistance only in the fully hardened condition. Type 420 is magnetic in all conditions.
  • Type 431 is a nickel bearing (1.252%) chromium stainless steel which may be heat treated to high mechanical properties. It is magnetic in all conditions of use. It has superior corrosion resistance to Types 410, 416, 420, 430 and 440 stainless steels.
  • Type 440C is the stainless steel that can be heat treated to the highest hardness of any of the stainless steels.

State : The state of a solenoid valve refers to the position of the valve, hence a solenoid valve in the open state is open allowing the flow of media, or closed state preventing the flow of media passing through the valve.

Static Seal : A seal or diaphragm used between two fixed parts that do not move, such as a seal between a valve bonnet and body or solenoid core tube seal. The seal is static and does not move.

Steam : Steam is vaporised hot water which occurs typically at +100°C at normally atmospheric pressure. The higher the pressure the higher the temperature required to boil water to generate steam, adversely the lower the pressure the lower the boiling point of water. The pressure and temperature of steam can be reasonably estimated from the table below. Steam applications require more specialised high temperature rated solenoid control valves typically with PTFE seals and Class H or Class N solenoid coils.

Stem : A stem is a connecting shaft or rod that transmits a mechanical force from a hand wheel, lever or valve actuator into the valve gate or piston to control the valve open and closed positioning.

Stop Off : A procedure to isolate a pipeline in the absence of a shut off valve whereby a collar is temporarily welded onto the pipe and an expandable plug hot tapped (whilst under line pressure) and inserted to shut off the pipeline.

Submersible : A valve or equipment that will be used underwater or sub-sea installation, typically requiring special treatment to resist seawater corrosion and external water pressure. For electrical enclosures and IP ingress protection rating equal or exceeding IP68 is required. See IP ratings.

Surge : A surge pressure is a sudden extreme or excessive rise in pressure within a pipeline caused by emergency pump shut-down or sudden valve closures. Surge pressures can exceed the maximum working and burst pressures of a valve or pipeline which can result in catastrophic failure.

Sweet Gas : Sweet gas is a natural gas with very low or insignificant amounts of Hydrogen Sulphide (Hâ‚‚S), unlike sour gas that has a high content of Hydrogen Sulphide (Hâ‚‚S) exceeding 4 PPM volume Hâ‚‚S.

Swing Check Valve : A swing check valve is a non return or one way valve that allows the flow of media in only one direction. The gate or shut off element is a flap or gate suspended or hung from an over head hinge allowing the gate to swing against or away from a sealing face.

Solenoid Valve Terminology T

Tapered Thread : A tapered thread is narrow at the front and becomes slightly wider at each thread pitch. Tapered threads are designed to seal at the thread itself and typically no O ring or bonded washer is used

TEE : A tee is a pipeline outlet at 90 degrees to the pipeline shaped like a "T" to fluid or gas media to be taken from the pipeline. Commonly used to replace large expensive 3 way solenoid valves by installing a T piece and two low cost 2/2 way solenoid valves on each leg or outlet, giving the advantage of total control of flow, both ports open or both ports closed, unlike a three way valve which is typically open to one or the other outlet.

Temperature : Temperature is a measurement of heat intensity, a very important factory when using valves to control a fluid or gas. The minimum and maximum media and ambient temperatures are normally required to assist in selecting the correct valve for the application. Temperature is typically measured in degrees Centigrade or degrees Fahrenheit.

  • You can convert from ºF to ºC by adding 40 then multiply by 5 then divide by 9 then subtract 40.
  • You can convert from ºC to ºF by multiply by 9, then minus 40, divide by 5 then add 40.

Temperature Rating : The maximum or minimum working or operating temperature range of equipment typically given as degrees Centigrade or degrees Fahrenheit.

Tensile Strength : Tensile strength (TS) sometimes referred to as (UTS) Ultimate Tensile Strength is the maximum amount of tensile stretching or pulling "tension" force that a valve, pipework or material can withstand before rupturing, cracking or breaking.

Test Certificate : A test certificate, letter or document supplied by the valve manufacturer to document and certify that the equipment has been tested. Testing may involve pressure, function, sealing and or operation depending on the test certification requested. Test certificates should always be requested during the quotation stage so that the valve supplier or manufacturer may perform the test and the customer aware of the additional charges commonly applied.

Threaded Solenoid Valves : Typically an internal thread measured by size and thread type, for example 1/4" BSP thread would be 1/4" British standard pipe thread as found in most of Europe and sometimes referred to a "G" or in this case G1/4", in most parts of America NPT (National Pipe Taper) is the common thread and in most parts of Asia PT is the common thread.

Throttling Valve : A throttling valve is designed to restrict, reduce, regulate or control the flow of media rather than simple open or closed operation.

Thru Conduit : Through conduit is the terminology associated to a valve typically a ball valve where the passage or flow path through the valve is smooth or clear without any obstacle, obstruction, cavities or gaps to either restrict media flow or trap debris.

Thrust : Thrust is a force or push applied in one direction, such as the force exerted on a valve piston or solenoid valve armature assembly.

Tight Shut Off. (TSO) : A tight shut off valve is a valve that can close virtually leak free. Typically found on single seat valves (one sealing face) as double seat valves (two sealing faces) can leak between 1 to 3%. See bubble tight valves for better sealing.

Timer : Timers are electrical or sometimes mechanical devices installed into electrical circuits that control the electrical power supply to the valve and will offer a pre-set adjustable automated control for valves.

Torque : Torque is the measure of force or turning power typically measured in Kg/Cm Kilograms per centimetre or Ft/Lb foot / pounds, being the load or weight applied at a distance from the shaft axis. For example 50 foot pounds equates to 50 lbs applied to the end of a 12" or 1 foot long wrench or lever.

Torque Switch : A torque switch is a safety switch commonly found on electric motors in electric actuators that is designed to cut electrical power to the electric motor if the applied torque or turning forces of the motor are exceeded.

Torsional Spring : A torsional spring is a spring that is wound around a shaft or twisted to exert a rotational force or torque. Torsional springs are found in non return swing check valves and spring return actuators where the spring will automatically mechanically return the valve back to its default position.

Trim : Valve trim refers to the working parts of a valve, a solenoid valve trim would be the solenoid armature, core tube, seals and gaskets.

Trunnion : A trunnion are the ball valve parts that hold the internal rotating ball in a stable vertical axis, i.e. the same axis as the stem.

Turns to Operate : The number of turns to operate a rotating valve hand wheel, T bar, stem or shaft to move the valve from the ully open to the fully closed position, or visa versa. Most actuated valves will utilise a gear box to reduce the require torque but in doing so will increase the number of turns to operate according to the gear ratio.

Solenoid Valve Terminology U

U- CUP or Ring Packing : A "U" shaped ring found in some valves where grease can be pumped to seal the valve during an emergency, known as Emergency Seat Sealing.

UL Approval : UL is an American independent safety (Underwriters Laboratories) certification. A UL listing means that UL have tested samples of the product and determined that it meets UL's requirements. These requirements are based primarily on UL's published and nationally recognised American Standards of Safety. UL approved solenoid actuated valves can be verified by their UL number at the UL database on-line.

Ultimate Strength : The ultimate strength of a valve or material is the maximum applied stress at which the valve or material will break.

Ultrasonic Inspection : An ultrasonic inspection procedure using ultrasonic or high frequency sound waves to view the internal structure of metal castings and welds to locate imperfections, voids and cracks.

Underground Storage : Underground storage tanks (UST) have at least 10% of their structure under ground level or surface of surrounding soil and are connected to pipelines as an underground storage facility for liquids or gases.

Unions : A union is a pipeline pressure tight metal to metal faced two piece joint or union with a threaded connecting sleeve that applies sealing force between the two connecting metal faces. This allows a pipe to be disconnected without the need to rotate or remove any of the existing connecting pipework.

Union Bonnet : A valve bonnet or top cover that in screwed onto the valve body rather than bolted. Typically found on gate valves where the valve bonnet can be unscrewed for maintenance.

Universal : A universal solenoid valve is a function typically associated to a 3/2 way universal solenoid valve, whereby the inlet port can be any of the three ports with flow in any direction.

Solenoid Valve Terminology V

Vacuum : Vacuum is negative pressure or suction, typically measures as Torr or mmHG, Micron, psia, inches mercury gauge, inches mercury absolute and kPa. The maximum possible achievable vacuum is -1 bar or - 1 atmosphere such as outer space.

Valve : A valve is a mechanical device designed to control, prevent or restrict the flow of gas or liquid media along a pipeline.

Valve Body : The valve body is the main part of the solenoid valve in which the connecting ports, seals and seats are located

Valve Specifications : Valve specifications include valve type, size, materials of construction, minimum and maximum operating pressures and temperatures, function, connection type and minimum and maximum operating and working pressures. Some valve specifications and dictated by globally recognised standards such as:

  • ASTM A126-04 Standard Specification for Gray Iron Castings for Valves, Flanges and Pipe Fittings.
  • ASTM A182/A182M-04 Standard Specification for Forged or Rolled Alloy-Steel Pipe Flanges, Forged Fittings and Valves and Parts for High-Temperature Service.
  • ASTM A338 Standard Specification for Malleable Iron Flanges, Pipe Fittings and Valve Parts for Rail road, Marine and Other Heavy Duty Service at Temperatures Up to 650°F (345ºC).
  • ASTM A522/A522M-01 Standard Specification for Forged or Rolled 8 and 9% Nickel Alloy Steel Flanges, Fittings, Valves and Parts for Low Temperature Service
  • ASTM A694/A694M-03 Standard Specification for Carbon and Alloy Steel Forgings for Pipe Flanges, Fittings, Valves and Parts for High Pressure Transmission Service.
  • ASTM A961-04 Standard Specification for Common Requirements for Steel Flanges, Forged Fittings, Valves and Parts for Piping Applications.
  • ASTM A988/A988M Standard Specification for Hot Isostatic-ally-Pressed Stainless Steel Flanges, Fittings, Valves and Parts for High Temperature Service.
  • ASTM A989/A989M Standard Specification for Hot Isostatic ally-Pressed Alloy Steel Flanges, Fittings, Valves and Parts for High Temperature Service.
  • ASTM B61-2 Standard Specification for Steam or Valve Bronze Castings
  • ASTM B763 Standard Specification for Copper Alloy Sand Castings for Valve Application.
  • ASTM B834 Standard Specification for Pressure Consolidated Powder Metallurgy Iron Nickel Chromium Molybdenum (UNS N08367) and Nickel Chromium Molybdenum Columbium (Nb) (UNS N06625) Alloy Pipe Flanges, Fittings, Valves and Parts
  • ASTM C1129 Standard Practice for Estimation of Heat Savings by Adding Thermal Insulation to Bare Valves and Flanges.
  • ASTM F885 Standard Specification for Envelope Dimensions for Bronze Globe Valves NPS 1/4 to 2.
  • ASTM F992 Standard Specification for Valve Label Plates.
  • ASTM F993 Standard Specification for Valve Locking Devices.
  • ASTM F1020 Standard Specification for Line-Blind Valves for Marine Applications.
  • ASTM F1030 Standard Practice for Selection of Valve Operators.
  • ASTM F1098 Standard Specification for Envelope Dimensions for Butterfly Valves NPS 2 to 24.
  • ASTM F1271 Standard Specification for Spill Valves for Use in Marine Tank Liquid Overpressure Protections Applications.
  • ASTM F1370 Standard Specification for Pressure-Reducing Valves for Water Systems Shipboard.
  • ASTM F1394 Standard Test Method for Determination of Particle Contribution from Gas Distribution System Valves.
  • ASTM F1565 Standard Specification for Pressure-Reducing Valves for Steam Service.
  • ASTM F1792 Standard Specification for Special Requirements for Valves Used in Gaseous Oxygen Service.
  • ASTM F1793 Standard Specification for Automatic Shut-Off Valves (also Known as Excess Flow Valves, EFV) for Air Or Nitrogen Service.
  • ASTM F1794 Standard Specification for Hand Operated, Globe-Style Valves for Gas (Except Oxygen Gas) and Hydraulic Systems.
  • ASTM F1795 Standard Specification for Pressure Reducing Valves for Air or Nitrogen Systems.
  • ASTM F1802 Standard Test Method for Performance Testing of Excess Flow Valves.
  • ASTM F1970 Standard Specification for Special Engineered Fittings or Valves for use in Polyvinyl chloride (PVC) or Chlorinated PolyVinyl Chloride (CPVC) Systems.
  • ASTM F1985 Standard Specification for Pneumatic Operated, Globe-Style, Control Valves.
  • ASTM F2138 Standard Specification for Excess Flow Valves for Natural Gas Service.
  • ASTM F2215 Standard Specification for Balls, Bearings, Ferrous and Nonferrous for Use in Bearings, Valves and Bearing Applications.
  • ASTM F2324 Standard Test Method for Prerinse Spray Valves.

Velocity : Velocity is speed of an object, gas or liquid measured as distance over time. The velocity of a gas or liquid along a pipeline is commonly given as Ft/Sec or feet per second.

Vent Plug : A vent plug a threaded nipple or plug that is screwed into a pipeline or valve body, which when removed will allow the contents of the pipeline or valve cavity to vent out to atmosphere, so that the pipe or valve can be inspected or maintained.

Vertical Pattern : A vertical pattern valve is a valve whose ports (inlet and outlet) share a common axis (in line with each other) and are suited for mounting in a vertical position.

Viscosity : Viscosity of fluids can be measured in different ways, Say-bolt Universal Seconds, Engler degrees, Kinematic centistokes. See table below that show

Visual Position Indicator (VPI) : A visible mechanical indicator or arrow that shows the position of a valve, normally protected by a transparent plastic cover or shield.

Voltage : Voltage or volts is an electrical measurement or electromotive force, the difference of potential that would carry one ampere of current against one ohm resistance. Voltage (Volts) is a measure of force. Amperes typically a measure of electric current.

Volume : Volume is a capacity measurement usually measured in litres, gallons, pint or fluid ounces. Typically used to show how much fluid can pass through a valve over a given period.

  • 1 gallon (UK) = 4.54 litres
  • 1 gallon (USA) = 3.79 litres
  • 1 Pint (UK) = 0.57 litres
  • 1 Pint (USA) = 0.47 litres
  • 1 fluid once (UK) = 28.4 cm³
  • 1 fluid once (USA) = 29.6 cm³

Solenoid Valve Terminology W

Wall Thickness : The wall thickness of the material of a pressure bearing pipe, tube or pressure vessel. For example a pipe with an outside diameter (OD) of 25mm with a wall thickness of 2.5mm will have an internal diameter of 20mm. (25mm - 2x 2.5mm of pipe thickness each side).

Water : Water (Hâ‚‚O) is typically a clear, transparent odourless liquid with density or specific gravity of 1, turns into a solid (ice) at 0°C or steam at 100°C at atmospheric pressure. water forms the sea, lakes, rivers and rain and is the foundation of life on earth. Water is the most common fluid controlled in process systems and there is a wide range of valves designed to control water. Water is available in many forms, such as sea water, clean process water and even pure or de-mineralised water. We drink water, wash with water, process food and drinks with water, even cool, wash and flush process systems with water.

Water Hammer : The audible effects of pressure waves generated by rapid changes in fluid velocity or speed