Description
DN20 Coaxial Solenoid Valve 0-40 Bar – RSG 27020
The RSG 27020 is a high-performance DN20 direct acting coaxial solenoid valve designed for reliable control of liquids, oils, gases, vacuum and compatible industrial process media from 0 to 40 Bar. Its pressure-balanced coaxial construction requires no minimum differential pressure, providing dependable switching from zero pressure through to high-pressure applications.
Unlike conventional pilot-operated diaphragm valves, the RSG 270 Series uses a coaxial plunger arrangement with the actuator positioned around the fluid flow path. This design is particularly suited to demanding industrial applications involving high pressures, frequent switching and thick or glutinous fluids with viscosities up to 1000 cSt.
The DN20 version provides a Kv flow coefficient of 7.0 m³/h with standard 1/2", 3/4" or 1" BSP connections. The manufacturer specifies 0–40 Bar operating pressure with back-pressure sealing up to 16 Bar in the reverse A→P direction.
Valve Function & Operation
The RSG 27020 is a 2/2 way direct acting coaxial valve available in either normally closed or normally open configurations.
270A20 – Normally Closed
The valve remains closed without electrical power and opens when the solenoid is energised.
270B20 – Normally Open
The valve remains open without electrical power and closes when energised.
Because the valve is direct acting, operation does not depend upon inlet pressure or a minimum pressure differential across the valve. This provides reliable switching from 0 Bar through to 40 Bar.
DN20 Ports & Connections
The standard DN20 RSG 27020 is available with:
✓ G1/2 BSP
✓ G3/4 BSP
✓ G1 BSP
Optional connection configurations include:
✓ NPT Threads
✓ Special Connections
✓ PN16 Flanges
✓ PN40 Flanges
✓ PN100 Flanges
This allows the same coaxial valve technology to be incorporated into threaded or flanged industrial pipework.
Pressure & Performance
Operating Pressure: 0 to 40 Bar
Forward Flow P→A: Maximum 40 Bar
Reverse Flow A→P: Maximum 16 Bar
Nominal Diameter: DN20
Kv Flow Coefficient: 7.0 m³/h
Water Flow: Approx. 117 L/min @ 1 Bar ΔP
Weight – Brass Version: 5.4kg
The coaxial design therefore combines true zero-pressure operation with substantially higher pressure capability than the 20 Bar RSG 269 Series.
Flow Capacity
The DN20 valve has a Kv flow coefficient of 7.0 m³/h.
The RSG 270 range provides:
DN10 – Kv 2.5 m³/h
DN15 – Kv 5.2 m³/h
DN20 – Kv 7.0 m³/h
DN25 – Kv 12.3 m³/h
DN32 – Kv 20.0 m³/h
Coaxial Valve Design
The RSG 270 Series uses a characteristic coaxial construction, with the solenoid surrounding the central plunger and fluid path.
The principal internal components comprise the adapter fittings, valve seat, plunger, solenoid, spring and twin PTFE rod seals. The actuator force acts directly along the same axis as the fluid flow, allowing operation independently of minimum differential pressure.
This design is particularly useful for:
✓ Zero-Pressure Applications
✓ High-Pressure Applications
✓ Thick & Glutinous Fluids
✓ Oils & Lubricants
✓ Compact Machinery Installations
✓ Bidirectional Pressure Duties
✓ Frequent Switching Applications
High Viscosity Fluids
The RSG 27020 is suitable for thick and glutinous fluids with viscosities up to 1000 cSt.
This makes the coaxial design particularly useful for applications involving:
✓ Thick Oils
✓ Hydraulic Oils
✓ Lubricating Oils
✓ Viscous Process Fluids
✓ Glutinous Industrial Liquids
The direct acting coaxial construction avoids reliance on the small pilot passages used by conventional servo-operated diaphragm valves, making it particularly useful where thicker media can create operational problems for conventional valve designs.
Construction & Materials
Threaded body materials are available in:
✓ Brass
✓ AISI 303 Stainless Steel
✓ AISI 316 Stainless Steel
Flanged versions can also be manufactured using galvanised steel, nickel-plated steel or AISI 316 stainless steel.
Standard Seal Construction
Static Seal: FKM
Dynamic Seals: PTFE
Valve Seat: FKM or PTFE
Optional seal configurations include:
✓ NBR
✓ EPDM
The choice of body and seal materials allows the RSG 270 Series to be configured for a broad range of industrial media.
Media Compatibility
Typical applications include:
✓ Water
✓ Hydraulic Oils
✓ Lubricating Oils
✓ Thick Process Fluids
✓ Compressed Air
✓ Industrial Gases
✓ Process Liquids
✓ Cooling Fluids
✓ Compatible Chemicals
For aggressive chemicals or unusual process fluids, compatibility should be confirmed against all wetted materials before ordering.
Special Service Options
The RSG 270 Series can be configured for specialist media and process requirements in addition to standard industrial fluid applications.
Available configurations include:
✓ Water Service Seal Options
✓ Gas Service Seal Options
✓ Oxygen Service Options
✓ Vacuum Service Option
✓ High Leak-Tightness Version
✓ Oil & Grease-Free Construction
Different body materials, seat seals and valve configurations can be selected according to the application and required media compatibility.
For oxygen, vacuum, gas or applications requiring particularly low leakage rates, the required service should be specified when ordering to ensure the correct valve configuration is supplied.
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 resistance and low friction. The dynamic sealing arrangement helps strip limescale and debris from the sealing surface during operation.
This makes the configuration particularly useful where water quality or deposits could reduce the service life of 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 low friction, excellent wear characteristics and broad chemical compatibility, making it suitable for appropriately specified industrial gas applications.
Increased Leak-Tightness Version
An increased leak-tightness configuration to 10⁻⁵ mbar·L/sec is available for demanding gas and vacuum applications.
This specialist configuration includes:
✓ Oil & Grease-Free Cleaning
✓ Special Valve Seat Treatment
✓ Special Seal Components
✓ Helium Leak-Tightness Testing
Vacuum Service
A dedicated vacuum configuration is available.
Combined with its direct acting zero-differential design suitable for vacuum equipment requiring controlled switching between pressure, working and return connections.
Oxygen & Clean Service
Oil and grease-free construction is available for specialist clean-service applications, including appropriately specified oxygen-service configurations.
Valves for oxygen service can be supplied degreased and prepared for the application. The required oxygen service, pressure, materials and cleaning specification should be confirmed when ordering.
Temperature
Media Temperature: -10°C to +100°C
Ambient Temperature: -10°C to +50°C
Coil & Electrical Specification
Electrical Duty: 100% ED
Protection: IP65 with plug fitted
Connection: DIN EN 175301-803 Form A
Voltage Tolerance: ±10%
Mounting Position: Any Position
The valve may be installed in any mounting position, providing considerable flexibility when integrating the 27020 into machinery and process equipment.
Voltage Options
Standard manufacturer voltage options are:
✓ 24VDC
✓ 230VAC 50Hz
✓ Special Voltages On Request
For AC operation, the electrical connector incorporates a rectifier.
DN20 power consumption:
24VDC – 45 Watts
230VAC 50Hz – 53 Watts
Energy Saving PWM Connector Option
The 24VDC version can be fitted with an optional DIN Form A PWM power-reduction connector.
This initially supplies the power required for reliable valve actuation before reducing the electrical holding power after the valve has switched.
Potential benefits include:
✓ Reduced Holding Power
✓ Lower Coil Temperature
✓ Reduced Energy Consumption
✓ Lower Enclosure Temperature
✓ Extended Solenoid Service Life
✓ Ideal For Continuous Duty
Optional Features & Accessories
The RSG 270 Series can be configured with:
✓ Manual Override
✓ E1 Position Indication
✓ E2 Position Indication
✓ Mounting Brackets
✓ LED DIN Connector
✓ PWM Power Reduction Connector
✓ IP65 Terminal Box
✓ M12x1 Electrical Connector
✓ Vacuum Configuration
✓ Oil & Grease-Free Construction
✓ Special Connections
Position Indication
Optional electrical position indication is available for applications requiring confirmation of valve position.
E1 – Single Position Indication
E2 – Double Position Indication
This can be particularly useful for automated machinery, process control systems and installations where valve status feedback is required.
Typical Applications
✓ High Pressure Liquids
✓ Thick & Glutinous Fluids
✓ Hydraulic Systems
✓ Lubrication Systems
✓ Compressed Air Systems
✓ Industrial Gas Systems
✓ Vacuum Systems
✓ Process Engineering
✓ Industrial Automation
✓ Cooling Systems
✓ Water Treatment Equipment
✓ Chemical Processing Equipment
✓ Laboratory Equipment
✓ Machine Tool Systems
✓ OEM Machinery
✓ Zero Pressure Applications
Why Choose a Coaxial Valve?
A conventional pilot-operated solenoid valve requires sufficient pressure differential to lift its diaphragm or piston. This can make it unsuitable for zero-pressure systems, closed-loop circuits and applications where pressure can equalise across the valve.
The RSG 27020 is direct acting from 0 Bar, so switching does not depend upon pressure differential.
Its DN20 coaxial construction combines increased flow capacity with zero-pressure operation, high-pressure capability and suitability for thick process fluids, providing a robust valve solution for demanding industrial applications.
Available Versions
270A20 – Normally Closed
270B20 – Normally Open
Standard DN20 connections:
✓ 1/2" BSP
✓ 3/4" BSP
✓ 1" BSP
Standard voltages:
✓ 24VDC
✓ 230VAC 50Hz Rectified
RSG Coaxial Valve Pressure Ranges
RSG 269 Series – up to 20 Bar
RSG 270 Series – up to 40 Bar
RSG 271 Series – up to 64 Bar
RSG 272 Series – up to 100 Bar
The RSG 270 Series provides a high-pressure option for applications requiring greater pressure capability than the standard 269 Series while retaining direct acting operation from zero pressure.
Related Products & Categories
