Key Features
✓ DN40 2/2 Way Coaxial Valve
✓ Pneumatically Pilot Operated
✓ Normally Closed Operation
✓ Normally Open Version Available
✓ Zero Differential Pressure
✓ 0–100 Bar Operating Pressure
✓ 16 Bar Reverse Pressure
✓ 3–8 Bar Pilot Pressure
✓ Kv 45.7 m³/h Flow Capacity
✓ 1½" BSP Connection
✓ Brass or Stainless Steel Body
✓ FKM & PTFE Seals
✓ Fluids Up To 1000 cSt
✓ -10°C to +100°C Media
✓ NAMUR Pilot Interface
✓ Vacuum Service Option
✓ Oil & Grease-Free Option
✓ Position Indication Option
✓ ATEX Sensor Option
✓ Mounting Brackets Available
✓ Modular Manifold Options
✓ Free UK Delivery Available
Datasheets
Description
DN40 2/2 Way Coaxial Air Pilot Valve – RSG 28140
The RSG 28140 is a DN40 2/2 way externally controlled coaxial air pilot valve designed for reliable shut-off and control of compatible liquids, gases, vacuum and industrial process media at pressures from 0 to 100 Bar.
Independent pneumatic actuation allows reliable operation from zero differential pressure, without relying upon process pressure to generate the switching force. The valve uses a double-acting piston with return spring, controlled by a 3–8 Bar pilot air supply through G1/4 pilot connections with a NAMUR interface.
The DN40 version provides a large 40mm nominal diameter with a Kv flow coefficient of 45.7 m³/h. Standard process connection is 1½" BSP, with NPT, flange and special connection options available.
Valve Function & Operation
The RSG 28140 is an externally controlled 2/2 way coaxial valve available in normally closed or normally open configurations.
281A40 – Normally Closed
The valve remains closed in its normal unactuated position and opens when the pneumatic pilot actuator is operated.
281B40 – Normally Open
The normally open version provides the opposite fail-state, remaining open until the pneumatic actuator is operated.
Because switching force is supplied independently by the pneumatic pilot system, the valve does not require process pressure or a minimum differential pressure to operate.
DN40 Ports & Connections
The standard DN40 RSG 28140 is supplied with:
✓ G1½ BSP
Optional connections include:
✓ NPT Threads
✓ Flanged Connections
✓ Special Connections
Flanged configurations are available for high-pressure process installations where threaded connections are unsuitable.
Pressure & Performance
Operating Pressure: 0 to 100 Bar
Reverse Pressure: Up to 16 Bar
Pilot Pressure: 3 to 8 Bar
Nominal Diameter: DN40
Orifice: 40mm
Kv Flow Coefficient: 45.7 m³/h
Water Flow: Approx. 637 L/min @ 1 Bar ΔP
Weight – Brass Version: 11.7kg
Flow direction:
P → A: Up to 100 Bar
A → P: Up to 16 Bar
The DN40 RSG 28140 combines a large flow path with substantially higher operating pressure than the corresponding 64 Bar RSG 280 Series valve.
Flow Capacity
The DN40 RSG 28140 provides a conventional Kv flow coefficient of 45.7 m³/h.
Practical flow data for this configuration gives approximately 637 litres/minute of water at 1 Bar pressure difference.
This combination of high flow capacity, zero-differential operation and 0–100 Bar operating pressure makes the RSG 28140 particularly suitable for demanding high-pressure process installations where both pressure and flow capacity are important.
Externally Controlled Coaxial Design
The RSG 281 Series combines a coaxial process-valve construction with an externally controlled pneumatic actuator.
The actuator consists of a double-acting piston with return spring, operated by a 3–8 Bar pneumatic pilot supply.
Pilot connections are G1/4 and the NAMUR interface allows a suitable 5/2 way pilot solenoid valve to be mounted directly to the actuator.
This arrangement is particularly useful for:
✓ High-Pressure Applications
✓ High Flow Applications
✓ Frequent Switching
✓ Industrial Process Control
✓ High Viscosity Fluids
✓ Oils & Lubricants
✓ Vacuum Systems
✓ Automated Process Equipment
Switching Performance
Opening and closing times are approximately 50–1000 milliseconds, depending upon operating pressure, pilot pressure, pilot valve selection and optional exhaust-air throttles.
Optional exhaust throttles allow the pneumatic switching characteristics to be adjusted where controlled opening or closing is required.
High Viscosity Fluids
The RSG 28140 is suitable for compatible thick and glutinous fluids with viscosities up to 1000 cSt.
Typical applications can include:
✓ Thick Oils
✓ Hydraulic Oils
✓ Lubricating Oils
✓ Viscous Process Fluids
✓ Glutinous Industrial Liquids
Media compatibility should always be confirmed against the selected body and sealing materials.
Construction & Materials
Body materials are available in:
✓ Brass
✓ AISI 303 Stainless Steel
✓ AISI 316 Stainless Steel
Internal Components: Stainless Steel
Stainless steel versions provide an alternative for applications requiring greater corrosion resistance or compatibility with more demanding process media.
Standard Seal Construction
Standard sealing materials include:
✓ FKM Static Seals
✓ FKM & PTFE Dynamic Seals
✓ PTFE Seat Seal
Optional seal configurations include:
✓ NBR
✓ EPDM
The appropriate sealing configuration can be selected according to the process medium, temperature and application requirements.
Media Compatibility
Typical applications include:
✓ Hydraulic Oils
✓ Lubricating Oils
✓ Thick Process Fluids
✓ Process Liquids
✓ Cooling Fluids
✓ Compatible Chemicals
✓ Viscous Fluids Up To 1000 cSt
Air, water and gas applications require the appropriate custom-made configuration. Please contact us with the media and operating conditions so the correct valve and sealing arrangement can be specified.
For aggressive chemicals, specialist gases or unusual process fluids, compatibility should be confirmed against all wetted materials before ordering.
Special Service Options
The RSG 281 Series can be configured for specialist media and process requirements in addition to standard industrial fluid applications.
Available configurations include:
✓ Water Service Seal Options
✓ Air Service Configurations
✓ Gas Service Seal Options
✓ Vacuum Service Option
✓ Oil & Grease-Free Construction
✓ Special Connections
Different body materials and sealing arrangements can be selected according to the application and required media compatibility.
Water Service Seal Option
For demanding water applications, UHMW Polyethylene seals are available with a maximum service temperature of +80°C.
UHMW Polyethylene provides excellent wear and abrasion resistance together with very good lubricity in water-based media.
The sharp-edged dynamic seal creates a stripping action against the moving valve component, helping remove limescale and debris during operation.
This makes the configuration particularly useful where deposits or contamination could otherwise affect conventional sealing arrangements.
Gas Service Seal Option
For demanding gaseous applications, Fluoroloy® A21 seals are available with a maximum service temperature of +80°C.
Fluoroloy A21 provides excellent wear resistance, low friction and broad chemical compatibility, together with high sealing performance for appropriately specified gaseous media.
Vacuum Service
A dedicated vacuum configuration is available for the RSG 281 Series.
Because actuation is provided independently by the pneumatic pilot circuit, operation does not depend upon pressure within the process line. This makes the RSG 28140 particularly useful for vacuum and zero-pressure applications.
Temperature
Media Temperature: -10°C to +100°C
Ambient Temperature: -10°C to +50°C
Water Seal Option: Up to +80°C
Gas Seal Option: Up to +80°C
The appropriate sealing arrangement should be selected according to the process medium and required operating temperature.
Pneumatic Pilot Specification
Actuation: External Pneumatic Pilot
Actuator: Double-Acting Piston
Return: Spring Return
Pilot Pressure: 3–8 Bar
Pilot Connections: G1/4
Interface: NAMUR
Mounting Position: Any Position
An upstream air preparation unit is recommended to provide a clean pilot-air supply and help maximise pneumatic actuator service life.
NAMUR Pilot Valve Option
Optional 5/2 way NAMUR pilot solenoid valves can be mounted directly to the actuator, providing electrical control of the pneumatic pilot system.
Available pilot solenoid voltages include:
✓ 24VDC
✓ 230VAC 50Hz
Pilot valves can be supplied with lateral or top-facing connections according to installation requirements.
Optional Features & Accessories
The RSG 281 Series can be configured with:
✓ Mounting Brackets
✓ Exhaust Air Throttles
✓ Sintered Bronze Silencers
✓ NAMUR Pilot Solenoid Valves
✓ Open Position Indication
✓ Closed Position Indication
✓ M12 Position Sensors
✓ ATEX Position Sensors
✓ Vacuum Configuration
✓ Oil & Grease-Free Construction
✓ Modular Manifold Systems
✓ Special Connections
✓ Flanged Connections
Position Indication
Optional inductive or magnetic position sensors can provide electrical confirmation of the valve's open and/or closed position.
These can provide valve-position feedback to PLCs, machinery controls and automated process systems.
Open and/or closed position indication can be specified according to the control-system requirements.
ATEX Options
The RSG 281 Series can be configured with explosion-protected electrical accessories for hazardous-area applications.
Available options include an explosion-protected pilot solenoid and intrinsically safe position sensing.
Where the Ex pilot-solenoid configuration is selected, permissible valve operating pressure is reduced by approximately 20%, so the required pressure should be confirmed when specifying an ATEX version.
Typical Applications
✓ High-Pressure Fluid Control
✓ High Flow Process Systems
✓ Hydraulic Systems
✓ Lubrication Systems
✓ Thick & Glutinous Fluids
✓ Viscous Process Fluids
✓ Chemical Processing Equipment
✓ Pressure Testing Equipment
✓ Test Rigs & Process Skids
✓ Vacuum Systems
✓ Industrial Automation
✓ OEM Machinery
✓ Automated Process Systems
✓ Modular Manifold Systems
Why Choose the RSG 281 Series?
The RSG 281 Series provides the same robust externally controlled coaxial design as the RSG 280 Series but increases operating pressure for more demanding industrial applications.
Because switching force comes from the 3–8 Bar external pilot supply, operation remains independent of process pressure. This provides reliable switching from zero differential pressure and makes the design particularly useful for vacuum, viscous fluids and high-pressure applications.
The RSG 28140 combines this operating principle with 0–100 Bar pressure capability, a large DN40 flow path and substantial Kv 45.7 m³/h flow capacity.
Available Versions
281A40 – Normally Closed
281B40 – Normally Open
Standard DN40 connection:
✓ 1½" BSP
Optional:
✓ NPT
✓ Flanged Connections
✓ Special Connections
RSG Air Pilot Coaxial Valve Ranges
RSG 280 Series – DN10-DN50 up to 64 Bar
RSG 281 Series – DN10-DN25 up to 120 Bar
RSG 281 DN32-DN50 – Up to 100 Bar
RSG 282 Series – DN10-DN25 up to 160 Bar
The DN40 RSG 28140 provides the large-bore 100 Bar option within the RSG 281 range, combining substantially increased flow capacity with the externally controlled coaxial valve design.
Related Products & Categories
Technical Specification
Brand: RSG regel-und steuergeräte gmbh
Model: 28140
Width: 110.00 mm
Height: 110.00 mm
Depth: 304.00 mm
Weight: 11.70 kg
Valve / Product Type: Air Actuated Valve, Coaxial Valve
Body Material: Brass, Stainless Steel
Port Size: 11/2 thread
Function: 2/2 Failsafe Closed, 2/2 Failsafe Open
Operation: Direct Acting
Pressure: 70 Bar, 80 Bar, 90 Bar, 100 Bar
Seals: EPDM, NBR, PTFE (Teflon), FKM (Viton)
Media: Air, Fluid (Non Aggressive), Fluid (Slight Acid/Alkali), Gases (Non Aggressive), Oils + Fuels 50cSt Max, Fluid Thick 51>500cSt, Water, Water (RO/Pure/Demin)
Orifice: 40mm
Options required: Bi-Directional Flow, Manifold, Manual Override, Mounting Bracket, Mounting Holes, Position Feedback Closed, Position Feedback Open+Closed
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