Description
WRAS Pneumatic Wafer Butterfly Valve – EPDM Lined PN16
Heavy-duty WRAS approved pneumatically actuated wafer butterfly valve designed for potable water, water treatment and industrial wet-media applications requiring reliable automatic isolation or flow control.
The valve combines an epoxy-coated ductile iron wafer body, EPDM liner and 316 stainless steel disc with a robust 90° pneumatic actuator.
Available with either double-acting or spring-return pneumatic actuation, allowing the valve to be configured for standard open/close operation or failsafe applications.
WRAS Approved for Potable Water
WRAS Approval: 2211362
Designed for drinking-water and potable-water installations subject to the conditions of the WRAS approval.
The EPDM liner provides the wetted sealing surface between the valve body and disc, making this configuration particularly suitable for water and compatible wet, non-abrasive fluids.
Valve Design
Pattern: Wafer
Function: Quarter-turn butterfly valve
Pressure range: 0–16 Bar
Flange compatibility: PN6, PN10, PN16 and ANSI/ASA Class 150
Rotation: 90°
Body: Epoxy-coated ductile iron
Liner: EPDM
Disc: ASTM A351 CF8M 316 stainless steel
Disc pin: 316 stainless steel
Shaft: Stainless steel 416
Lower long bushing: FRP
Upper short bushing: FRP
Top O-ring: NBR
Pneumatic Actuation
The valve can be supplied with either a double-acting or spring-return pneumatic actuator depending on the required control and safety function.
Double Acting
Compressed air is used to drive the valve in both directions, providing positive pneumatic opening and closing.
Spring Return
Compressed air operates the actuator in one direction with an internal spring pack providing the return stroke.
Spring-return versions are suitable for applications requiring a predetermined failsafe open or failsafe closed position following loss of compressed-air supply.
Pneumatic Actuator Specification
Operation: Double acting or spring return
Rotation: 90°
Travel adjustment: ±5°
Air connections: 1/4" BSP
Interface: NAMUR
Maximum air supply: 10 Bar
Actuator body: Hard-anodised extruded aluminium alloy
End caps: Epoxy-coated die-cast aluminium
Pinion: Nickel-plated alloy steel
Piston seals: NBR
Pinion guides: Self-lubricating polypropylene with glass-fibre reinforcement
Springs: High-tensile steel
Position indicator: Visual open/closed indication
Lubrication: Pre-lubricated moving components
Design cycle life: Up to 1,000,000 operations
Media & Temperature
Suitable media:
✓ Potable water
✓ Clean water
✓ Process water
✓ Wet non-abrasive fluids
✓ Compatible non-abrasive liquids
Valve media temperature: −10°C to +80°C
Actuator ambient temperature: −20°C to +80°C
Wafer Pattern Installation
The compact wafer-pattern body is designed to install between mating pipeline flanges, providing a considerably shorter face-to-face dimension than many conventional isolation valves.
Compatibility with PN6, PN10, PN16 and ANSI Class 150 flange patterns makes the range suitable for new installations, replacement valves and OEM equipment.
Spring Return Failsafe Option
For safety-critical or automatic isolation duties, a spring-return actuator can be selected to move the butterfly valve automatically to its designated safe position if the compressed-air supply is lost.
Depending on actuator assembly, this can provide:
✓ Air-to-open / spring-to-close
✓ Air-to-close / spring-to-open
✓ Automatic response to air failure
✓ Reduced dependence on external controls
That's a worthwhile section because "failsafe pneumatic butterfly valve" is useful search intent in its own right.
NAMUR Automation Options
The pneumatic actuator's NAMUR interface allows compatible automation accessories to be fitted, including:
✓ NAMUR solenoid valves
✓ ATEX solenoid valves
✓ Position feedback switches
✓ Limit switch boxes
✓ Position indicators
✓ Pneumatic control accessories
This also gives you a nice internal-linking opportunity to your NAMUR and ATEX solenoid valve ranges.
Typical Applications
✓ Potable water systems
✓ Water treatment plants
✓ Building services
✓ Pumping systems
✓ Tank isolation
✓ Process water systems
✓ Industrial water control
✓ Automated pipework systems
✓ OEM machinery
✓ Failsafe water isolation
Robust Industrial Construction
The combination of an epoxy-coated ductile iron body, EPDM liner and CF8M 316 stainless steel disc provides a durable valve assembly for water and compatible wet-media applications.
The pneumatic actuator uses an anodised aluminium body, coated end caps, nickel-plated pinion and pre-lubricated internal components for dependable quarter-turn operation in industrial environments.
Why Choose a Pneumatic Butterfly Valve?
Pneumatically actuated butterfly valves provide rapid and reliable automation of larger pipeline sizes while maintaining a compact installation envelope.
Compared with manual operation, pneumatic actuation enables the valve to be integrated into automated process systems, PLC controls and safety circuits, while spring-return versions can provide a mechanical failsafe response following loss of air supply.
