LH45X-16 Flow Check Valve

LH45X-16 Flow Check Valve, also known as silent slow-closing duckbill check valve, is a special ductile iron non-return valve widely installed on pump outlets, municipal water supply pipelines, sewage networks and fire-fighting systems. Model LH45X stands for silent slow-closing structure, while 16 represents its nominal pressure PN16, which can bear a maximum working pressure of 1.6MPa. Unlike swing check valves and lift check valves with loud closing impact, this valve adopts an integrated rubber duckbill sealing structure, featuring silent closing, small water hammer impact, stable flow control and reliable one-way flow blocking performance. It effectively prevents medium reverse flow after pump shutdown and protects water pumps, motors and pipe fittings from damage caused by reverse rotation and pressure shock.

The valve body is cast from high-strength ductile iron, with full fusion bonded epoxy coating on both inner and outer surfaces. The coating layer is uniform, smooth, non-toxic and corrosion-resistant, fully meeting sanitary standards for drinking water delivery. The core sealing component is an integrally molded EPDM rubber duckbill liner fixed inside the valve cavity. When water flows forward, fluid pressure pushes the rubber lip open to form a full straight flow channel with ultra-low flow resistance and little pressure loss. Once the water pump stops running and medium pressure decreases, the elastic rubber lip automatically fits tightly under reverse water pressure to achieve complete one-way shutoff without any leakage. The flexible rubber structure avoids rigid collision between metal parts, eliminating closing noise and greatly weakening destructive water hammer.

This check valve has a compact and streamlined internal structure without complicated swing discs, guide shafts or springs, which significantly reduces failure points and maintenance frequency. There is no dead space inside the valve cavity, so silt, impurities and suspended solids in raw water or reclaimed water will not accumulate and block the valve. The flanged connection design makes installation and disassembly convenient; workers can quickly replace the internal rubber duckbill without cutting pipelines during routine maintenance, greatly saving construction time and maintenance costs. The overall weight is lighter than traditional swing check valves of the same caliber, lowering pipeline bearing load and construction difficulty.

LH45X-16 silent flow check valve covers complete specifications from DN50 to DN1200, suitable for clean tap water, fire-fighting water, industrial circulating water, rainwater and low-concentration sewage with medium temperature between 0℃ and 80℃. It does not need any hydraulic or electric auxiliary control devices and works automatically relying only on fluid pressure difference, with simple matching for all types of centrifugal water pumps. Compared with common slow-closing check valves, it has lower operating torque, quieter operation and stronger anti-clogging capacity, especially suitable for buried valve wells and indoor pump rooms with strict noise control requirements.

Compliant with GB/T13927 and international pipeline valve standards, LH45X-16 flow check valve has outstanding comprehensive performance. It is the preferred supporting valve for waterworks, secondary water supply pump stations, high-rise building fire protection systems, sewage lifting stations and industrial cooling water pipelines. With silent operation, anti-water hammer effect, anti-blocking property and long service life, it solves the two prominent problems of pipeline reverse flow and closing impact, providing stable and safe one-way protection for all kinds of water delivery systems.