Plate thickness for end of pipe Hydrostatic Test 1

[carlomaderazo]

Kindly give me a calculation of plate thickness to be used for hydrostatic test..

 

[BigInch]

http://www.smflanges.com/blind-flanges.html

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"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[Ron]

carlo....I would generally suggest that it would be helpful when you ask a question if you would give a bit of information along with it; however, you seem very unfamiliar with hydrostatic testing, which can be very dangerous if not done properly. I would suggest that you get someone locally, who is familiar with hydrostatic testing, to assist you.

As BigH suggests, if you have a flanged connection, a blind flange will already be sized for your pressure application according to the flange class and the pipe class. If you are just using a blocking plate, get someone local to help you as it will entail thickness design and weld design.

 

[C2it]

Don't even think of welding a flat plate to the end of your pipe to hydrotest.

 

[brandonb73]

You can also use a weld cap, then cut it off after the test.

 

[racookpe1978]

Well, yes, a welded-on cap could be used, but then you get into the circular logic of having to cut off a perfectly good, temporary tested joint, and then re-welding that same joint into the permanent configuration, then having to re-test the final joint you just welded.

it would be valid only for a shop test - but then the final hydro reqmt is still not met.

A operational pressure test with the operating fluid is OK to accept a bolted (flanged) joint if the piping system welds have been hydro'ed, but the higher hydro test is required for your butt-welded joints at some point in time. Or a 100 percent X-ray. Or both - depending on your insurance/pressure/temperature. HP/HT Steam, LT/HP main feed water, LT/LP/flammable turbine lube oil, and low temperature low pressure condensate water will have different requirements when new pipes are added.

 

[carlomaderazo]

Ron, i appreciate your concern. I am familiar in hydrostatic testing but of course I am not familiar in special case like this. If I will ask some local consultant, I think I don't need to raise this question in this forum.
The reason I need the calculation is because we need to fabricate blind flange from the steel plate.

 

[carlomaderazo]

Well folks, I found the answer from the previous thread..see the link below:

http://www.eng-tips.com/viewthread.cfm?qid=43256