Product Introduction

This product is a new type of check valve developed by our factory's technicians with reference to advanced domestic and foreign counterparts. It features a novel structure, rational design, excellent sealing performance, low fluid resistance, large flow rate and long service life. Equipped with a duct control system on the main valve, it operates automatically via hydraulic power to achieve optimal opening/closing speeds, thereby preventing water hammer and water impact. It realizes slow-closing and noise reduction, making it an ideal choice for water supply systems in high-rise buildings. Welcome to purchase!

300X Piston Type Slow-Closing Check Valve Product Diagram

Working Principle

When the water pump starts operating, the water flow at the inlet end of the valve passes through the micro filter (16), needle valve (15), and check valve (14) into the control chamber of the valve cover, and then is discharged to the outlet through the ball valve (6). Since the opening of the needle valve (15) is small (usually 1/4 turn open is sufficient) and the diameter of the inlet pipe is smaller than that of the outlet pipe, the discharge speed in the control chamber is greater than the water supply speed at the inlet. As a result, the pressure in the control chamber decreases, and the inlet pressure acting under the main valve disc (5) lifts the main valve disc, thereby opening the main valve to supply water downstream.

When the water supply stops, the water downstream starts to flow back. Due to the self-weight of the valve disc (5) and the pressure in the upper water chamber, the throttle port is quickly closed by 90%. The remaining 10% uses the pipe to transmit the pressure behind the valve to the upper water chamber. Due to the action of the check valve (14), the water in the upper water chamber cannot flow out, so the pressure in the water chamber gradually increases, and the valve stem moves down slowly, finally making the main valve disc close tightly. This prevents the backflow of downstream water and plays the role of slow closing and noise elimination. (This is the working principle of the diaphragm type, and the piston type is the same.)