piping hydro testing

[foxy55]

Are you allowed to hydrt test through a 3" plug valve on new piping or do you have to remove it from the system

 

[pennpiper]

Unless it is a really cheap knock-off brand made by someone in a back alley welding shop you can hydrotest with the valve in place.

Determine the proposed test pressure and contact the manufacturer for confirmation.

prognosis: Lead or Lag

 

[zdas04]

You better be able to test through a plug valve or any other accessory--if it can't handle the test pressure then you have the wrong system MAWP.

Testing against a closed plug valve is another issue. Plug valves are less likely to hold against test pressure than ball valves or even gate valves. With any of these you often have to put in skillet blinds to keep from invalidating your test just because the valve leaked through.

David Simpson, PE
MuleShoe Engineering

"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
The plural of anecdote is not "data"

 

[gerhardl]

To add to zdas04: You can if you do not go over the MAWP of the valve. If you do, the valve will have lost the guarantee from the producer, and the responsibillity for performance falls on you. Note: closed valve MAWP is generally lower than body/open valve MAWP.