The Ductile Iron Silent Check Valve (also called a spring-loaded check valve or nozzle check valve) is specifically designed to eliminate water hammer — the pressure surge that occurs when a traditional swing check valve slams shut. The valve features a disc (or poppet) that is held open by forward flow pressure. As forward flow decreases, a stainless steel spring begins pushing the disc toward the closed position. The disc makes contact with the seat just as forward flow reaches zero — before reverse flow can start. This “pre-closure” action prevents any reverse flow from developing, eliminating water hammer completely. The result is silent operation and protected downstream piping and pumps. The valve can be installed in any orientation (horizontal, vertical up, or vertical down).
Why Choose Us / Advantage
ISO 5208 Rate A Sealing: Zero leakage in reverse direction.
Anti-Water Hammer Guarantee: Eliminates damaging pressure surges (tested per API 622).
Compact Design: Wafer type saves 70% of the weight and length of a swing check valve.
Stainless Steel Internals: Disc guide, stem, and spring are all SS304 or SS316.
Used in High-Rise Buildings: Thousands installed in buildings over 50 floors.
Technical Data
★ Type Spring-Loaded Silent Check
★ Body Ductile Iron QT450
★ Disc Ductile Iron + EPDM / SS304
★ Spring SS302 / SS316
★ Guide SS304 / SS316
★ Pressure PN16 / PN25 / Class 150
★ Size Range DN50 – DN600
★ Connection Wafer (EN 558 Series 46)
Applications
● High-rise building water supply risers
● Boiler feedwater and condensate return
● Hot water circulation systems
● Pharmaceutical and food-grade water lines
● Marine and offshore platforms
