Description
3/8" Normally Open Stainless Solenoid Valve – SHAKO SPU220AN-03
The SHAKO SPU220AN-03 is a high-performance 3/8" 2/2 way normally open zero-rated assisted-lift solenoid valve manufactured from corrosion-resistant 316 stainless steel.
Designed for applications requiring fail-open operation, the valve remains open without electrical power and closes when the solenoid operator is energised.
Its zero-rated assisted-lift design allows operation from zero positive pressure and is suitable for vacuum service, making it particularly useful for compressed air, water, vacuum, light oils and compatible aggressive or high-purity process fluids.
A large 13mm orifice provides approximately 35 L/min water flow at 1 Bar pressure differential. FKM (Viton) seals are fitted as standard, with NBR, EPDM and HNBR alternatives available. For AdBlue / DEF applications, select the EPDM seal configuration.
Valve Function & Operation
Function: 2/2 way normally open
Operation: Zero-rated assisted lift
Failsafe position: Open
Energised position: Closed
Construction: Diaphragm
Port size: 3/8" BSP
Optional threads: NPT or Rc
Orifice: 13mm
The SPU220AN-03 is normally open when electrically de-energised. Applying electrical power energises the solenoid operator and closes the valve.
If electrical power is removed or lost, the valve automatically returns to its normally open position.
This fail-open operating principle makes the SPU220AN-03 particularly suitable for processes where fluid or gas flow must continue in the event of electrical power loss.
Its assisted-lift construction combines direct mechanical actuation with diaphragm assistance, allowing operation from zero positive pressure without requiring the minimum differential pressure associated with conventional pilot-operated valves.
Pressure & Performance
15W AC pressure range: 0 to 7 Bar
18.5W AC pressure range: 0 to 12 Bar
18.5W DC pressure range: 0 to 12 Bar
Vacuum service: Suitable
Orifice size: 13mm
Flow rate: 35 L/min water @ 1 Bar ΔP
Media viscosity: Maximum 50 cSt
Opening / closing time: ≤50ms
For DC operation we supply the higher-power 18.5W operator, providing operation from zero positive pressure through to 12 Bar.
For AC applications, the standard 15W configuration can be used up to 7 Bar, while the 18.5W high-power configuration extends the operating pressure to 12 Bar.
Construction & Materials
Body: 316 stainless steel
Tube: Stainless steel
Internal components: Stainless steel
Construction: Assisted-lift diaphragm
Orifice: 13mm
Standard seal: FKM (Viton)
Optional seals:
✓ NBR
✓ EPDM
✓ HNBR
Installation: Coil upright
Net weight: Approximately 0.74kg
Seal & Media Selection
Correct seal selection is essential when using the SPU220AN-03 with different fluids and temperatures.
FKM (Viton) – Standard:
✓ -10°C to +180°C
✓ Oils and fuels
✓ Many process fluids
✓ Higher temperatures
NBR:
✓ -15°C to +80°C
✓ Air
✓ Water
✓ Neutral gases
✓ Mineral oils
HNBR:
✓ -40°C to +150°C
✓ Air
✓ Water
✓ Oils
✓ Low-temperature service
EPDM:
✓ -5°C to +130°C
✓ Water
✓ Hot water
✓ AdBlue / DEF / AUS 32
✓ Suitable aqueous fluids
For AdBlue / DEF applications, select the EPDM seal configuration rather than the standard FKM version.
Always confirm chemical compatibility before using the valve with aggressive chemicals, fuels, oxygen or unusual process fluids.
Media Temperature
The maximum media temperature is determined by the selected seal material and suitable solenoid operator.
FKM (Viton): -10°C to +180°C
NBR: -15°C to +80°C
EPDM: -5°C to +130°C
HNBR: -40°C to +150°C
Overall available range: -40°C to +180°C
Flow Performance
Orifice size: 13mm
Flow rate: 35 L/min water @ 1 Bar ΔP
The 13mm assisted-lift diaphragm provides high flow capacity while retaining normally-open, zero-rated operation.
Unlike conventional pilot-operated diaphragm valves, the SPU220AN-03 does not require positive inlet-to-outlet differential pressure to initiate operation.
This allows the valve to combine high flow, zero-pressure starting and fail-open operation within a compact 3/8" stainless steel valve.
Coil & Electrical
Standard AC coil: 15W
High-power AC coil: 18.5W
DC coil: 18.5W high-power
Insulation: Class H 180°C
Duty cycle: 100% continuous
Electrical connection: DIN43650A
Protection: IP65 with connector fitted
Coil construction: Thermoset resin
For DC applications, the 18.5W high-power operator is used as standard to provide useful pressure capability through to 12 Bar.
For AC applications, select the operator according to required pressure:
✓ 15W AC → up to 7 Bar
✓ 18.5W AC → up to 12 Bar
✓ 18.5W DC → up to 12 Bar
The electrical data specifies continuous duty, Class H insulation, IP65 protection with connector and DIN43650A electrical connection.
Voltage Options
18.5W DC options:
✓ 12V DC
✓ 24V DC
✓ 48V DC
✓ 110V DC
✓ 220V DC
15W AC options:
✓ 24V AC
✓ 48V AC
✓ 110V AC
✓ 240V AC
✓ 380V AC 50/60Hz
18.5W AC options:
✓ 24V AC
✓ 48V AC
✓ 110V AC
✓ 230V AC 50/60Hz
RO & Pure Water Options
The 316 stainless steel construction makes the SPU220AN-03 suitable for many RO water, demineralised water and high-purity water applications.
Where the process fluid has specific purity or material-compatibility requirements, the exact wetted materials and selected operator configuration should be confirmed before ordering.
For high-purity applications, degreased versions are also available.
ATEX / IECEx Option
An explosion-protected solenoid operator option is available for suitable hazardous-area applications.
Optional nass magnet operator:
✓ Ex mb IIC T4 Gb
✓ Ex mb tb IIIC T130°C Db
✓ ATEX Category 2G / 2D
✓ Zone 1 Gas / Zone 21 Dust
✓ Gas Group IIC
✓ Dust Group IIIC
✓ IP65 protection
✓ 100% duty
ATEX Certificate: PTB 03 ATEX 2086 X
IECEx Certificate: IECEx PTB 05.0005X
Maximum media temperature: +80°C
The optional explosion-protected coil with a maximum differential pressure of 3 Bar.
Special Options
✓ NPT or Rc thread options
✓ NBR seal option
✓ EPDM seal option
✓ HNBR seal option
✓ AdBlue EPDM configuration
✓ High-power 18.5W operator
✓ Alternative coil voltages
✓ High-temperature configuration
✓ Degreased configuration
✓ Flanged versions available
Typical Applications
✓ Normally-open process control
✓ Fail-open safety systems
✓ Chemical process systems
✓ Corrosive fluid control
✓ RO water systems
✓ Demineralised water systems
✓ Pure water systems
✓ AdBlue / DEF with EPDM seals
✓ Vacuum applications
✓ Water treatment equipment
✓ Air and inert gas control
✓ Light oil systems
✓ OEM machinery
✓ Industrial automation
High Flow Normally Open Design
The SHAKO SPU220AN-03 combines corrosion-resistant 316 stainless steel construction with a 13mm zero-rated assisted-lift diaphragm and normally-open fail-safe operation.
Its 13mm orifice provides approximately 35 L/min water flow at 1 Bar pressure differential while allowing operation from zero positive pressure.
The valve remains open without electrical power and energises to close, making it fundamentally different from the normally-closed SPU220A series.
For AC applications, the standard 15W operator provides operation up to 7 Bar. Where higher pressure is required, the 18.5W operator increases maximum pressure to 12 Bar.
For DC applications, we use the 18.5W high-power operator, providing the full 0–12 Bar pressure range rather than using the lower-power coil configuration.
Ordering Information
Select the required seal material, thread, voltage and pressure range before adding the valve to your basket.
Available configurations include:
✓ 3/8" BSP thread
✓ Optional NPT or Rc threads
✓ FKM seals as standard
✓ NBR, EPDM or HNBR options
✓ EPDM configuration for AdBlue
✓ 15W AC up to 7 Bar
✓ 18.5W AC up to 12 Bar
✓ 18.5W DC up to 12 Bar
✓ Normally-open fail-safe operation
✓ High-temperature configuration
✓ Degreased configuration
✓ ATEX operator option
For DC voltage, the 18.5W high-power coil is supplied.
For AdBlue / DEF / AUS 32, select the EPDM seal configuration.
For oxygen service, specify the appropriate degreased configuration and confirm the complete application requirements before ordering.
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