Disc check valve DN 125-300 - 932 | AWS

AWS 932 DN125–DN300 – Disc-Spring Check Valve

The AWS 932 DN125–DN300 is a wafer-type check valve with a spring-loaded disc, designed for installation between flanges. It is suitable for liquid and gas media without solids, where short face-to-face dimensions and automatic closure on reverse flow or pump shutdown are required. No actuator is provided or required.

Technical Data

• Sizes: DN125–DN300 / 5"–12"
• Connections: DIN EN 1092-1 B1 PN10–PN40, ASME B16.5 Class 150
• Options: ANSI 300, special flange dimensions, lug type body
• Face-to-face: DIN EN 558 Series 49; DN250 and DN300 per AWS company standard
• Temperature range: -196°C to +400°C, depending on body and seat materials
• Pressure: up to 50 bar, pressure-temperature rating per DN
• Kv: 201 to 867 m³/h
• Opening pressure: approx. 9–68 mbar, depending on DN, installation orientation, and spring selection

Materials and Sealing

Available with body in 1.4408 / A351 CF8M, 1.0619 galvanized / A216 WCB, 1.4469 superduplex / A890 Grade 5A, or superduplex body with 1.4408 internals. Springs are 1.4571 or Hastelloy C4 for superduplex versions.

Seats: metal, NBR, EPDM, FKM, PTFE. Metal seat: leakage rate G per EN 12266-1. Soft seats: leakage rate A, minimum backpressure 0.3 bar required for rated tightness.

Applications

Suitable for industrial water, cooling, seawater, desalination, utilities, air, and compatible gases or liquids. For seawater or brine, superduplex or aluminium bronze variants are recommended, with chloride, temperature, and flow velocity assessment.

Installation

Requires clean piping, correct flow direction, and centering between flanges. Manufacturer recommends straight pipe section 5×DN upstream and downstream of the valve. Avoid direct mounting on pump flange. Springless operation is only permitted in vertical lines with upward flow.

FAQ

Is maintenance required? Specified as maintenance-free; operational and leakage checks are determined by plant operator.

When is a smaller DN required? If noise or low flow prevents the disc from remaining fully open, consider downsizing.