The Pressure Testing Methods for Check Valve
Check valve is a kind of valve that relies on the flow of the medium to automatically open and close the valve flap to prevent the backflow of the medium. It is also known as single direction valve, counterflow valve, and back pressure valve.
This type of valve works automatically. Under the fluid pressure flowing in one direction, the valve flap opens. When the fluid flows in the opposite direction, the valve seat is affected by the fluid pressure and self-overlaying valve flap, so that the flow is cut off.
The use of check valve:
Sanitary check valve is a kind of automatic valve. It’s mainly used to prevent the backflow of the medium, and prevent pump and actuating motor from reverse-rotating, and prevent the discharge of container medium.
Check valve can also be used in pipelines supplying the auxiliary system where the pressure may rise above the system pressure. Check valve can be divided into swing-type check valve (which rotates around the center of gravity) and lift-type check valve (which moves along the axis).
Pressure testing method:
The valve flap axis of lift-type check valve is in a position vertical to the horizontal surface. The channel axis and valve flap axis of swing-type check valve are in a position nearly parallel to the horizontal line.
For strength test, introduce test medium from the inlet to the specified value, the other end is closed. If there is no leakage from the valve body and cover, then it’s considered qualified.
For sealing test, introduce test medium from the outlet. At the inlet, check the sealing surface, stuffing and gasket. If there is no leakage from those places, then it’s considered qualified.