Check valve test state: lift check valve disc axis is in a position perpendicular to the horizontal; swing check valve channel axis and disc axis are in a position approximately parallel to the horizontal line.
During the strength test, the test medium is introduced from the inlet end to the specified value, and the other end is closed. It is qualified if there is no leakage in the valve body and bonnet. In the sealing test, the test medium is introduced from the outlet end, and the sealing surface is checked at the inlet end. No leakage at the packing and gasket is qualified.
