Principle of Hydraulic Non-Slam Check Valve
When the water valve supplies water from the inlet end of the valve, the water from the needle valve and one-way valve enters the cover control room and then is discharged downstream through the ball valve. Due to the small opening of the needle valve, the discharge speed of the control room is greater than that of the inlet to replenish water, thus reducing the pressure in the control room. The inlet pressure acting under the main valve disc all the time lifts the main valve disc, thereby opening the main valve disc and supplying water downstream. When the pipeline stops supplying water, the downstream water begins to flow back. Due to the effect of the one-way valve, the backflow water cannot flow out after entering the valve cover control room through the ball valve. As a result, the pressure of the group valve cover control room increases gradually and the main valve disc is closed tightly.