Heavy Duty Silent Check Valve HC41X-10C DN500 PN10 Flanged Cast Steel Mainline Non-Return Valve

The HC41X-10C silent check valve in nominal size DN500 (20") is a flanged cast steel non-return valve developed specifically to eliminate the loud slamming and water hammer that ordinary swing check valves produce when pumps stop. Instead of a free-hanging disc, this valve uses a spring-assisted single disc that tracks the flow closely and returns to the seat the moment forward velocity drops, so the closure is gradual, quiet and controlled. Every unit supplied by YUXIN is manufactured from high-grade WCB cast steel with a rubber soft seal, making the valve a dependable choice for water supply, drainage, HVAC circulation and industrial process lines where noise control and surge protection are equally important.

Because the disc is spring loaded and closes before reverse flow can develop, the valve protects pumps, flow meters, pressure vessels and pipe fittings from damaging pressure surges. The design is engineered for large-diameter mainline service, with a generously sized body that keeps flow resistance low while protecting the pipeline from surge events. The face-to-face dimension follows the Chinese national standard, and the flanged end connections allow direct installation between standard pipe flanges without additional adaptors. All exposed fasteners are zinc-plated steel, and the valve body is finished with a durable anti-corrosion primer coat suitable for outdoor, underground and plant-room environments.

• Genuine silent closure: spring-assisted disc movement absorbs kinetic energy and stops slamming noise at the moment of pump shutdown.
• Anti water hammer protection: the valve begins closing as flow decelerates, preventing surge pressure from travelling back into pumps and pipelines.
• WCB cast steel body: high mechanical strength, high pressure resistance and stable performance across a long service life.
• Rubber soft sealing: the EPDM sealing ring provides a tight, drip-free seal even when the line is idle or subject to vibration.
• Single disc spring structure: simple construction, fewer moving parts and easy maintenance compared with multi-disc or lever designs.
• Straight-through flow path: low pressure drop and full flow area keep pumping energy costs low in continuous duty systems.
• Corrosion-resistant trim: stainless steel spring and stem materials resist rust in fresh water, treated water and mildly aggressive media.

The DN500 HC41X-10C silent check valve is widely used at the discharge side of centrifugal pumps in municipal water supply stations, booster pump rooms, high-rise building water supply systems, HVAC chilled and hot water loops, fire protection systems, irrigation pumping stations and industrial circulating water systems. It is equally suitable for chemical plants, pharmaceutical and food processing facilities, metallurgical plants, power stations and wastewater treatment works where quiet, reliable one-way flow control is required. In every application the valve prevents return flow when the pump is switched off, protects upstream equipment from surge pressure and keeps the pipeline system operating with minimal noise and vibration.

Each valve is hydrostatically shell tested and seat tested before packing to confirm pressure integrity and sealing performance. Products are protected with foam padding and shipped in a strong plywood case or steel-framed wooden crate suitable for sea freight, with the flange faces covered to prevent transit damage. Standard export documentation, including packing list, commercial invoice and test certificate, is supplied with every order. YUXIN maintains large warehouse stock of popular diameters for fast dispatch, and our engineering team can provide selection advice, custom drilling and special material options. Contact us to confirm the exact specification, quantity and delivery schedule required for your project.