Finding the seat leakage location
Beside a shell test, the seat leakage test is the second element of a comprehensive control or shut-off valve test. For valve sizes up to DN200, the seat tightness as such is all that is of interest. However, the larger a valve the more important it is to know where a fund seat leak is exactly located. To find out the test bench operator needs to be able to inspect the seat from valves’ back side that is free of pressure.
To enable such inspection, CSV test benches starting with model 80/300 offer an optional swivel plate. Located on the B-side beam of the clamping unit it hosts the automatic seal head retainer when in its default position. When visual inspection becomes necessary, the clamping unit needs to be released with the valve hanging on a crane. The swivel plate is moved upwards giving way to an eyehole inside the B-side beam. The valve is now re clamped and the leak test pressure is set again with the operator having the chance to inspect the seats backside through the eye hole.