300X Slow Closing Check Valve

300X Slow Closing Check Valve is a hydraulically driven one-way protection valve specially matched for water pump outlet pipelines. It is widely adopted in municipal water supply, building water supply, fire pump rooms, water treatment stations and industrial circulating water systems. The main purpose is to prevent medium backflow after pump shutdown. By adopting two-stage slow closing mode, it effectively reduces water hammer shock, lowers pipeline vibration and noise, and protects water pumps and pipe fittings from impact damage.

The valve body is cast from high-strength ductile iron with reliable pressure resistance and structural rigidity. Standard pressure ratings include PN10 and PN16 with flanged connection for convenient field installation and overhaul. The valve runs completely relying on fluid pressure without external power. Supporting pilot control pipelines and adjustable needle valves allow technicians to set closing speed on site according to actual working conditions to achieve optimal anti-water hammer effect.

Working principle: When the pump starts, forward fluid pressure pushes the valve disc to fully open to maintain normal water supply. When the pump stops, medium tends to flow backward. Under the control of the pilot system, the valve disc performs two-stage closing action. It quickly closes most of the flow channel to limit backflow volume, then slowly completes the remaining closing stroke. This buffer design avoids fierce impact between disc and valve seat, significantly cutting instantaneous surge pressure inside pipelines.

Compared with common swing check valves, this product has obvious advantages in suppressing water hammer. It can reduce the configuration of auxiliary water hammer elimination equipment and simplify pump room pipeline layout. Complete specifications cover DN50 ~ DN800. Applicable media are clean water such as tap water, fire service water and cooling circulating water, suitable working temperature ranging from 0℃ to 80℃. Horizontal installation at pump outlet is recommended.

Installation & operation reminders: Install strictly in accordance with the flow arrow marked on the valve body. A Y-type strainer must be equipped upstream to avoid impurities blocking small-bore pilot pipelines. Improper adjustment of the needle valve will affect performance: excessively fast closing still creates water hammer, while too slow closing causes heavy backflow and may lead to pump reverse rotation. This valve only provides one-way protection and cannot act as a shut-off valve for long-term pipeline isolation.

All finished valves pass strict shell hydrostatic test, sealing test and closing action test before delivery. Each unit is inspected to ensure flexible disc movement and stable pilot control performance. Regular inspection of control pipelines can avoid blockage and guarantee long-term stable operation.

Featuring hydraulic self-operation, adjustable slow closing, outstanding anti-water hammer performance and reliable one-way sealing, 300X Slow Closing Check Valve is highly recognized by engineering contractors all over the world. Our factory can supply different flange standards and customized anti-corrosion coatings to meet various procurement requirements of water supply and fire engineering projects.