Disc check valve DN 15-100 - 931 | AWS

AWS 931 – Spring-Loaded Disc Check Valve

The AWS 931 is a wafer-type spring-loaded disc check valve designed for installation between flanges. The disc opens under differential pressure and closes via a spring mechanism when flow decreases or reverses. No actuator is provided. Intended for use with clean liquids and gases free of solids.

Technical Data

• Sizes: DN15–DN100
• Connection: Wafer, for installation between flanges PN6–PN16 and Class 150
• Face-to-face: DIN EN 558, Series 49
• Max pressure: up to 16 bar (pressure derates with temperature)
• Temperature range (metal seat): -10°C to +250°C
• Body: CW617N / 2.0402 brass
• Disc and spring cross: 1.4301
• Spring: 1.4401

Sealing Options

Metal seat suitable for operation up to +250°C, leakage rate ≥G per EN 12266-1. For reduced seat leakage, soft seals are available: NBR (to +90°C), EPDM (to +120°C), FKM (to +200°C), all with leakage rate A. Design 3 variant does not support PTFE seat.

Hydraulic Data

Kv values range from 2 m³/h (DN15) to 115 m³/h (DN100). Typical opening pressure is approx. 21 mbar in horizontal flow; values vary by installation orientation. Springless operation is possible only in vertical upward flow.

Applications

Suitable for HVAC, heating, cooling, general industrial piping, water, air, and compatible gases or liquids. Selection must verify compatibility of brass, stainless steel components, and seat material with the process fluid, temperature, and any chemical additives.

Installation / Maintenance

Correct flow direction, clean piping, centering between flanges, and straight pipe sections 5×DN upstream and downstream are required. Do not install directly on pump flanges. The series is maintenance-free; operational checks are the responsibility of plant personnel.

Standards & Certification

Compliant with PED 2014/68/EU, Annex III, Module A, and DIN EN 16668. For DN≤25, PED exempts CE marking.