hydrotesting check valve & gate valves

Hi All,

I like to know during hydrotesting is it normal practice to remove the internals of check valve and non return valves and replace it after testing .
Also is it normal practice to keep globe valves half open during hydrotesting. Do normally the valve data sheet specify this.Thanks
deepu varghese

It is NOT good practice to hydro-test through any valve! Hydro-testing is done to test the welds of the pipe fabrication, not the valve manufactures warranted pressure ratings. A number of times I’ve seen the field crew just string spool pieces together in what ever configuration the flanged ends allow, all with out any valves. The hydro-test is preformed, and then all the spools are disassembled and re-assembled in the design configuration with the valving. Now this is done only on small runs of small diameter pipe, usually tying in equipment packages. On larger runs I’ve seen the field crew use spec & paddle blinds at the valving, all to avoid hydro-testing thru the valves.