Description
1" Normally Open Stainless Steel Solenoid Valve – Pro-Uni-D CNS SUW25NO
The Pro-Uni-D CNS SUW25NO is a high-flow 1" 2/2 way normally open stainless steel solenoid valve designed for reliable control of air, water, light oils, vacuum and compatible industrial fluids and gases.
Featuring zero-rated assisted-lift operation, the SUW25NO operates from 0 Bar without requiring a minimum pressure differential. The normally open design provides fail-open operation, with the valve remaining open when de-energised and closing when electrical power is applied.
Manufactured from 316 stainless steel with stainless steel internal components, the SUW25NO features a large 25mm orifice providing up to 200 L/min water flow at 1 Bar pressure difference, making it particularly suitable for applications requiring high flow combined with zero-pressure and vacuum capability.
Valve Function & Operation
Function: 2/2 way normally open
Operation: Assisted lift / zero rated
Fail-safe position: Open
Electrical operation: Power to close
The SUW25NO remains open when electrically de-energised and closes when power is applied to the solenoid.
Power OFF → Valve OPEN
Power ON → Valve CLOSED
Power failure → Valve returns OPEN
The assisted-lift design allows the valve to operate from zero differential pressure, providing reliable switching where a conventional pressure-assisted diaphragm valve may not operate.
Ports & Connections
Port size: 1" BSP
Optional connection: NPT
Orifice: 25mm
Water flow: 200 L/min at 1 Bar pressure difference
The large 25mm orifice provides excellent flow capacity for water, compressed air, light oils, vacuum and compatible process applications.
Pressure & Performance
AC operating pressure: 0 to 10 Bar
DC operating pressure: 0 to 7 Bar
Minimum pressure differential: 0 Bar
Orifice: 25mm
Water flow: 200 L/min at 1 Bar pressure difference
Maximum media viscosity: 20 cSt
The zero-rated assisted-lift design combines high flow capacity with reliable operation at low and zero pressure differential.
Construction & Materials
Body: 316 stainless steel
Internal components: Stainless steel
Standard seals: NBR
Optional seals:
FKM / Viton®
EPDM
Silicone
The 316 stainless steel construction provides excellent corrosion resistance for demanding industrial, water, vacuum and process-control applications.
Seal & Media Compatibility
NBR seals are supplied as standard, with alternative seal materials available according to media and temperature requirements.
NBR: Air, water, light oils and compatible neutral media
FKM / Viton®: Oils and compatible process fluids
EPDM: Water and compatible aqueous media
Silicone: Specialist temperature and compatible fluid applications
Media compatibility should always be confirmed against the 316 stainless steel construction and selected seal material.
Suitable Media
Suitable applications include:
✓ Compressed Air
✓ Water
✓ Light Oils
✓ Vacuum
✓ Compatible Gases
✓ Compatible Process Fluids
Maximum media viscosity: 20 cSt
Other slightly aggressive fluids and gases may be suitable where compatible with the stainless steel construction and selected sealing material.
Vacuum Service
The SUW25NO is suitable for vacuum applications down to 10⁻³.
Its zero-rated assisted-lift construction allows operation without the minimum differential pressure normally required by conventional servo-operated diaphragm valves.
This makes the SUW25NO particularly useful where the system may operate between vacuum, atmospheric and positive pressure conditions.
Coil & Electrical
Coil: WPC2 Type S
Power: 29W
Insulation: Class F
Duty cycle: 90%
Protection: IP65 with connector fitted
Electrical connection: DIN 43650A
Approvals: UL and CE
The valve is supplied complete with the DIN electrical connector for straightforward installation.
Voltage Options
DC:
✓ 24VDC
AC:
✓ 24VAC with rectified connector
✓ 110VAC
✓ 230VAC
Alternative electrical configurations may be available according to application requirements.
Normally Open Fail-Safe Operation
The SUW25NO provides normally open fail-safe operation.
With no electrical power applied, the valve remains open and permits flow through the system.
When the solenoid is energised, the valve closes.
If electrical power is lost, the valve automatically returns to its open position.
This makes the SUW25NO suitable for systems where maintaining flow following electrical power failure is the required operating condition.
Typical Applications
✓ Industrial Water Systems
✓ Compressed Air Systems
✓ Vacuum Systems
✓ Cooling Water Systems
✓ Light Oil Control
✓ Inert Gas Systems
✓ Industrial Process Control
✓ Water Treatment Equipment
✓ Process Equipment
✓ OEM Machinery
✓ Laboratory Equipment
✓ Fail-Open Control Systems
High-Flow Zero-Rated Design
The SUW25NO combines a large 25mm flow orifice with zero-pressure differential operation, providing significantly greater flow capacity than conventional direct-acting solenoid valves.
The assisted-lift mechanism allows the solenoid to mechanically assist movement of the main valve element, enabling reliable operation from 0 Bar while retaining the flow advantages of a larger diaphragm valve.
With water flow up to 200 L/min at 1 Bar pressure difference, the SUW25NO is particularly suitable for larger pipework and high-flow systems where zero-rated or vacuum operation is required.
Why Choose the Pro-Uni-D SUW25NO?
The Pro-Uni-D CNS SUW25NO provides an effective solution for applications requiring normally open operation, high flow and zero-pressure capability in the same valve.
Its combination of a 25mm orifice, 200 L/min water flow, 316 stainless steel construction and assisted-lift operation makes it suitable for demanding industrial water, air, vacuum and process applications.
Multiple seal options, AC and DC voltages and optional NPT threads provide additional flexibility for OEM and industrial installations.
Ordering Information
Select the required:
Port – 1" BSP or optional NPT
Seal – NBR, FKM, EPDM or Silicone
Voltage – AC or DC
Media and operating pressure
Please contact us for quantity discounts or assistance selecting the correct valve configuration.
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