Silent Check Valve (Nozzle Type) – Class 150
Silent check valve with nozzle-type axial flow design and spring-assisted closure for water hammer prevention. Flanged ends per ASME B16.5. Body: ASTM A216 WCB / A351 CF8/CF8M. Sizes 1½" to 12". Zero slam, zero noise, leak-tight sealing. Ideal for pump discharge, water transmission, and HVAC systems.
Quick Summary
Silent Check Valve (Nozzle Type) = Spring-loaded axial flow check valve that closes BEFORE reverse flow occurs. The nozzle-shaped internal body guides the disc inline with spring-assisted rapid closure. Eliminates water hammer, slamming noise, and pressure surges. Also called non-slam check valve or nozzle NRV.
Key Specifications
How Silent Check Valves Prevent Water Hammer
Forward Flow
Flow lifts the disc off the nozzle seat, compressing the spring. Fluid passes through the annular gap between disc and body with minimal pressure drop.
Flow Deceleration
As flow slows down (e.g., pump stopping), the spring immediately begins pushing the disc back toward the seat — BEFORE any reverse flow develops.
Zero-Slam Closure
Disc seats on the precision-lapped nozzle face with zero reverse flow. No slam, no water hammer, no pressure surge, no noise. Leak-tight sealing achieved.
Bill of Materials
Applications
Pump Discharge
Reverse Flow Protection
Water Transmission
Pipelines & Networks
HVAC Systems
Chilled Water Loops
Fire Protection
Sprinkler Systems
Compressor Discharge
Air & Gas Systems
Boiler Feed Water
Steam Systems
Frequently Asked Questions
What is a silent check valve?
A spring-assisted axial flow check valve that closes before reverse flow occurs, preventing water hammer, slamming, and noise. The nozzle-shaped internal design guides the disc inline for rapid, precise closure.
How does it prevent water hammer?
The spring begins closing the disc as soon as forward flow decelerates — completing closure before any reverse flow develops. Zero slam, zero water hammer, zero noise.
Silent check vs swing check valve?
Silent check valves close before reverse flow (no water hammer), are compact/lightweight, and work in any orientation. Swing check valves are cheaper but rely on reverse flow to close (causing water hammer), require horizontal installation, and have longer closing time.
Need Silent Check Valves?
Protect your pumps and pipelines from water hammer. EN 10204 3.1 MTCs. Third-party inspection available.