BESPOKE VALVES

Provide valve solutions for a tidal drainage pump station at a river mouth in the Yangtze River Delta

The pump station is located in a tributary of the Yangtze River estuary, undertaking flood control and drainage tasks for 200000 acres of farmland and three towns along the coast. The tidal drop in the engineering area reaches 4.2 meters, and seawater is prone to backflow through the pump station pipeline during high tide, causing upstream freshwater pollution and pump impeller reversal; At the same time, when the ebb tide drainage alternates with the reverse flow of the flood tide, it frequently causes water hammer effects, which have led to problems such as pipeline interface leakage and pump motor overload.

Selection and Application Scheme of Check Valve
In response to the core requirements of “high drop, strong water hammer, and backflow prevention” in the project, the technical team ultimately selected the DN1200 slow closing butterfly check valve. The key design and application points are as follows:
1、Material adaptation: The valve body is made of duplex stainless steel 2205, and the sealing surface of the valve disc is made of a composite structure of hard alloy and fluororubber, which is resistant to seawater corrosion and sediment wear, solving the problem of erosion of the valve by tidal media;
2、Slow closing mechanism: Equipped with a hydraulic driven slow closing mechanism, the closing time of the valve disc can be adjusted within 3-15 seconds. The water flow direction and pressure changes are monitored in real time through sensors, and the switching rhythm of rising and falling tides is automatically adapted to avoid water hammer caused by rapid impact of the valve disc on the valve seat;
3、Installation layout: Install one check valve on each of the three outlet main pipelines of the pump station, and reserve a 15 meter buffer pipe section between the valve and the pump station to further reduce water flow impact. At the same time, pressure gauges and inspection holes are set up before and after the valve for real-time monitoring and maintenance.