Description
DN50 3/2 Way Coaxial Solenoid Valve – RSG 37050
The RSG 37050 is a high-flow DN50 direct acting 3/2 way coaxial solenoid valve designed for reliable directional control of liquids, gases, vacuum and compatible industrial process media from 0 to 16 Bar.
Unlike conventional pilot-operated valves, the RSG 370 Series operates directly from zero pressure without requiring a minimum differential pressure. Its coaxial construction provides positive switching between the P, A and R ports, making it particularly suitable for pressurising, venting, diverting and switching high-flow applications.
The DN50 is the largest valve in the RSG 370 Series, providing a substantial Kv flow coefficient of 42.0 m³/h, equivalent to approximately 700 L/min water flow at a 1 Bar pressure differential, with a standard 2" BSP connection.
Valve Function & Operation
The RSG 37050 is a direct acting 3/2 way coaxial valve available in either normally closed or normally open configurations.
370A50 – Normally Closed
In the de-energised position, pressure supply P is closed while the working port A is connected to return/exhaust R.
When energised, P connects to A and the return connection R is closed.
370B50 – Normally Open
The alternative normally open configuration reverses the switching function.
This 3-port arrangement allows a single coaxial valve to control both pressure supply and exhaust/return functions.
DN50 Ports & Connections
The standard DN50 RSG 37050 is supplied with:
✓ G2 BSP
Special connections can be supplied according to application requirements.
Pressure & Performance
Operating Pressure: 0 to 16 Bar
Reverse Pressure: Up to 16 Bar
Nominal Diameter: DN50
Kv Flow Coefficient: 42.0 m³/h
Water Flow: Approx. 700 L/min @ 1 Bar ΔP
Weight – Brass Version: 18.5kg
Flow pressure capability:
P → A: Up to 16 Bar
A → P: Up to 16 Bar
P → R: Up to 16 Bar
R → P: Up to 16 Bar
The direct acting construction allows reliable operation from 0 Bar without requiring a minimum pressure differential.
Flow Capacity
The DN50 RSG 37050 has a Kv flow coefficient of 42.0 m³/h, equivalent to approximately 700 L/min water flow at a 1 Bar pressure differential.
The RSG 370 range provides:
DN10 – Kv 2.5 m³/h
DN15 – Kv 4.5 m³/h
DN20 – Kv 6.8 m³/h
DN25 – Kv 11.5 m³/h
DN32 – Kv 17.9 m³/h
DN40 – Kv 34.0 m³/h
DN50 – Kv 42.0 m³/h
The DN50 provides the highest flow capacity within the RSG 370 Series and is designed for larger-volume applications operating up to 16 Bar.
3/2 Way Coaxial Valve Design
The RSG 370 Series uses a direct acting coaxial construction with three fluid connections:
✓ P – Pressure / Supply
✓ A – Working / Outlet
✓ R – Return / Exhaust
The actuator operates directly along the fluid flow axis, allowing the valve to switch without relying upon pilot pressure.
This construction provides fast, positive switching and is particularly useful for:
✓ Pressure & Exhaust Control
✓ High-Flow Applications
✓ Industrial Gases
✓ Thick & Glutinous Fluids
✓ Oils & Lubricants
✓ Vacuum Systems
✓ Test & Process Equipment
High Viscosity Fluids
The RSG 37050 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, seat and dynamic sealing materials.
Construction & Materials
Threaded body materials are available in:
✓ Brass
✓ AISI 303 Stainless Steel
✓ AISI 316 Stainless Steel
The choice of body material allows the valve to be configured for a wide range of industrial fluid, gas and process applications.
Standard Seal Construction
Static Seal: FKM
Dynamic Seal: PTFE
Valve Seat: FKM
Optional seal configurations include:
✓ NBR
✓ EPDM
✓ PTFE Seat Option
The appropriate sealing materials can be selected according to media, temperature and application requirements.
Media Compatibility
Typical applications include:
✓ Water
✓ Hydraulic Oils
✓ Lubricating Oils
✓ Thick Process Fluids
✓ Compressed Air
✓ Industrial Gases
✓ Process Liquids
✓ Cooling Fluids
✓ Compatible Chemicals
✓ Viscous Fluids Up To 1000 cSt
For aggressive chemicals or unusual process fluids, compatibility should be confirmed against all wetted materials before ordering.
Special Service Options
The RSG 370 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 for the RSG 370 Series.
Combined with its direct acting zero-differential design, this makes the RSG 37050 suitable for high-flow 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
Water Seal Option: Up to +80°C
Gas Seal Option: Up to +80°C
Coil & Electrical Specification
Electrical Duty: 100% ED
Protection: IP65 with connector fitted
Connection: DIN 43650A
Mounting Position: Any Position
DN50 power consumption:
24VDC – 73 Watts
230VAC 50Hz – 90 Watts
Voltage Options
Available voltage configurations include:
✓ 12VDC
✓ 24VDC
✓ 24VAC
✓ 110VAC
✓ 230VAC
✓ Other Voltages On Request
AC versions use an appropriate rectified electrical configuration.
Energy Saving PWM Connector Option
An optional PWM power-reduction connector is available to reduce holding power after the valve has switched.
The connector initially provides the power required for reliable actuation before automatically reducing the electrical holding power.
Potential benefits include:
✓ Up To 80% Lower Holding Power
✓ Lower Coil Temperature
✓ Reduced Energy Consumption
✓ Lower Heat Emission
✓ Improved Thermal Stability
✓ Extended Solenoid Service Life
✓ Ideal For Continuous Duty
Other voltage configurations can also be supported.
Optional Features & Accessories
The RSG 370 Series can be configured with:
✓ Manual Override
✓ Open Position Feedback
✓ Closed Position Feedback
✓ Volt-Free Feedback Switches
✓ LED DIN Connector
✓ Aluminium Terminal Box
✓ Mounting Brackets
✓ PWM Power Reduction Connector
✓ Vacuum Configuration
✓ Oil & Grease-Free Construction
✓ Special Connections
Position Indication
Optional volt-free position feedback switches can provide electrical confirmation of the valve's open and/or closed position.
This allows valve status to be incorporated into PLC systems, industrial automation, safety monitoring and process-control equipment.
Typical Applications
✓ Pressure & Exhaust Control
✓ High-Flow Liquid Systems
✓ High-Flow Pneumatic Systems
✓ Compressed Air Systems
✓ Industrial Gas Systems
✓ Vacuum Systems
✓ Hydraulic Systems
✓ Lubrication Systems
✓ Thick & Glutinous Fluids
✓ Viscous Process Fluids
✓ Process Engineering
✓ Chemical Processing Equipment
✓ Water Treatment Equipment
✓ Pressure Testing Equipment
✓ Test Rigs & Process Skids
✓ Industrial Automation
✓ OEM Machinery
✓ Large Manifold Systems
✓ Oxygen-Compatible Systems
Why Choose a 3/2 Way Coaxial Valve?
A 3/2 way valve combines pressure supply, working and return/exhaust functions within a single valve.
The RSG 37050 combines this functionality with direct acting coaxial technology, allowing reliable switching from 0 Bar without relying upon pilot pressure or minimum differential pressure.
With the largest nominal diameter in the RSG 370 range, a Kv 42.0 m³/h flow capacity, approximately 700 L/min water flow at 1 Bar ΔP, and compatibility with suitable fluids up to 1000 cSt, the DN50 is particularly suited to large industrial fluid, pneumatic, gas and process-control systems requiring high flow with positive 3/2 way switching.
Available Versions
370A50 – Normally Closed
370B50 – Normally Open
Standard DN50 connection:
✓ 2" BSP
Standard and optional voltages:
✓ 12VDC
✓ 24VDC
✓ 24VAC
✓ 110VAC
✓ 230VAC
RSG 3/2 Way Coaxial Valve Ranges
RSG 370 Series – DN10-DN32 up to 40 Bar
RSG 370 Series – DN40-DN50 up to 16 Bar
RSG 371 Series – DN10-DN32 up to 64 Bar
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