Swing Check Valve - ZRK / ZRKF | AWS

AWS ZRK / ZRKF – Wafer Type Swing Check Valve

The AWS ZRK and ZRKF are wafer-type swing check valves designed for installation directly between flanges. The ZRK operates via disc weight, while the ZRKF incorporates a return spring for controlled closure in non-horizontal or dynamic flow conditions. No actuator is used.

Technical Data

• ZRK: DN32–DN1000.
• ZRKF: DN32–DN400 (see datasheet), with return spring.
• Connections: EN flanges PN6–PN40, ASME Class 150/300, JIS 10K.
• Max pressure: 16–50 bar, depending on DN, material, and temperature.
• Temperature: ZRK -273°C to +500°C, ZRKF -200°C to +450°C, material dependent.

Materials and Sealing

Available in carbon steel, stainless steel 1.4408 or 1.4571, aluminium bronze CC333G, and superduplex 1.4469. Seat options: metal, NBR, EPDM, FKM/Viton, PTFE. Soft seats achieve leakage rate A per EN 12266-1; metal seat achieves leakage rate G.

Applications

Suitable for industrial liquid and gas networks, HVAC, water, wastewater, chemical plants, shipbuilding, and refineries. Not recommended for media with solid particles, as seat and disc movement may be affected.

ZRK vs ZRKF Selection

ZRK is selected for horizontal lines with stable flow and low opening pressure requirements. ZRKF is used where spring-assisted closure is needed, e.g., vertical installations, low flow rates, or where closure delay must be minimized.

FAQ

Can it be used in vacuum? Yes, with special configuration; for absolute pressure below 0.1 bar, bonded seat is recommended.
What should be specified before ordering? DN, flange standard, body/disc material, seat material, temperature, pressure, and minimum opening flow.