Installation for testing pressure tightness of check valve closing element

Claim 1

Apparatus for testing the pressure tightness of a closing element of a check valve, said apparatus comprising a container for receiving the check valve under test, means for clamping the valve at end faces thereof in the container and including a fixed sealing plug for engaging the valve at one end face, a movable sealing plug for engaging the valve at the other end face, and a pneumatic cylinder including a piston and piston rod, said piston rod being coupled to said movable plug, a source of compressed air, means for selectively connecting the pneumatic cylinder to the source of compressed air to clamp the valve to be tested between said plugs or to unclamp said valve, a source of gaseous test fluid, said fixed sealing plug having a channel connectible to the source of gaseous test fluid to receive the test fluid and pass the same into the valve, said movable plug having a channel connected to the valve to receive any test fluid leaking past the closing element of the valve, a liquid reservoir located under said container, a by-pass pipe connecting the reservoir and the container, said by-pass pipe having an upper end connected to said container and a lower end immersed into the liquid in the reservoir to permit liquid contained in the reservoir to flow to and from said container, means for selectively connecting said reservoir to said source of compressed air to cause liquid in the reservoir to be forced into the container and be maintained at a predetermined level so that testing of the check valve can be effected with the valve submerged in said liquid, the connection of said sources to the pneumatic cylinder, the reservoir and the channel of the fixed sealing plug being selectively controlled for permitting the valve to be clamped in the container without the presence of liquid therein and to introduce liquid into the container after the valve is clamped in place.