Axial Check Valves – Nozzle Check Valves in Cast Iron

What is an axial check valve?

An axial check valve (nozzle check valve) is a spring-loaded non-return valve whose disc is guided axially inside a nozzle-shaped body. It allows flow in one direction and prevents backflow in the opposite direction. The working principle follows the classic spring-loaded non-return valve design to DIN/EN standards.

Nozzle check valve vs. swing check valve: avoiding water hammer

The key advantage is the short stroke. Because the disc travels only a small axial distance, the valve closes before the flow reverses – unlike the long swinging arc of a conventional flap. This early, non-slam closure reduces pressure surges during pump trip.

Technical data & materials

Fergo supplies axial check valves in different nominal sizes, pressure ratings and materials for fast technical selection:

• Nominal size: DN50–DN300 (2''–12'')
• Connection: flange PN10/16 to EN 1092
• Body: grey cast iron EN-GJL-250 (GG25)
• Disc / guide: EN-GJS-400-15 (GGG40)
• Shaft: AISI 304L / 1.4307
• Spring: 1.4310 / AISI 302
• Seal: EPDM
• Temperature: –10 °C to +80 °C, max. pressure 16 bar (DN200 and above: 10 bar)

Check suitability for your medium in advance with our chemical resistance tool.

Applications

Axial check valves are used mainly on the discharge side of pumps, where they prevent backflow and water hammer. Typical fields are water and wastewater pumping, booster sets, cooling water circuits and building services. Their streamlined design keeps pressure loss low – a benefit also described for axial check valves on pump discharge lines. For larger sizes, wafer check valves are an alternative.

Selection & installation

The valve is installed in the flow direction (arrow on the body); spring-loaded versions can be mounted in any position. Match DN and PN to the EN 1092 flange standard and protect the valve against dirty media with an upstream Y-strainer. For an overview of all designs, see our industrial check valves category.

Axial check valves in GG25 reliably stop backflow and water hammer, close without slamming, and are available in DN50–DN300, PN10/16 from stock. Configure your valve by DN, PN and seal in the industrial check valves range, or request the matching certification with your order.