How do I test a pressure vessel containing Hydrogen
How do I test a pressure vessel containing Hydrogen
(OP)
I,
one of our subcontractor has tested a pressure vessel with dry nitrogen at 1.1 times the MAWP. But the vessel will keep -40F dewpoint hydrogen at 300 PSIG MAWP. According to me this test is not enough because according to the table of element, the atomic Weight of N is 14 times higher than H.
What kind of test normally are you testing that kind of equipment? Do you think Helium (He) pneumatic test will be better? Can you give some references to help me to find out wich test is better?
Thanks in advance,
hjulien
one of our subcontractor has tested a pressure vessel with dry nitrogen at 1.1 times the MAWP. But the vessel will keep -40F dewpoint hydrogen at 300 PSIG MAWP. According to me this test is not enough because according to the table of element, the atomic Weight of N is 14 times higher than H.
What kind of test normally are you testing that kind of equipment? Do you think Helium (He) pneumatic test will be better? Can you give some references to help me to find out wich test is better?
Thanks in advance,
hjulien





RE: How do I test a pressure vessel containing Hydrogen
lastly, test medium, depending upon code and/or client specs, usually is air, N2, or water.
Oh! pressure is pressure, independent of test medium used.
good luck!
-pmover
RE: How do I test a pressure vessel containing Hydrogen
Regards,
Mike
RE: How do I test a pressure vessel containing Hydrogen
Hjulien
RE: How do I test a pressure vessel containing Hydrogen
http:/
I am sure there are other threads to read as well. Just use the search tools here in the forums.
Reference UG-99(g)(1) and UG-100(d)(1) of Section VIII, Division 1:
A suitable gas leak test, if applied as a substitution of the hydrotest is acceptable only by agreement reached between Manufacturer and Authorized Inspector.
There are three kinds of people in this world; those who can count and those who can't.
RE: How do I test a pressure vessel containing Hydrogen
As for the ops question, mole weight has nothing to do with a pressure test, OK if the vessel is 3000 meters tall then it does, but does have a bearing on a leak test. As the link points out, you can calculate losses through a leak based on molecule size and with that you can get a ECONOMIC impact or your leak because it is your business how much hydrogen you want to allow to leak. All bets are off for other gases that are harmfull, but again, even the EPA has allowances for leaks of harmfull materials.
So you pick the economics, a $10,000 helium test to prove you'll lose $39 worth of hydrogen a year is your economic choice, but it won't improve the safety of you vessel.
RE: How do I test a pressure vessel containing Hydrogen
RE: How do I test a pressure vessel containing Hydrogen
RE: How do I test a pressure vessel containing Hydrogen
I am not familiar with when you would want to use a N2 pressure test in stead of hydro test.
Again, sorry for my previous clutter.
RE: How do I test a pressure vessel containing Hydrogen
Will left over water cause problems in the process, freezing, chemical reactions, fouling, corrosion.
Will the process cause problems the water. Was ther oil left in the vessel that would make the test water hard to dispose of or other chemicals.
Is water readily avaiable. Or could a compressed bottle of gas supply the small voulme required.
Can the work area be cleared enough to used a compressed gas, if not go back to water.
Does the equipment need to be inerted after the hydrotest before commisioning with the process, if so, skip the water since you'll be putting nitrogen in before the process fluids anyway.
I work mostly with cryogenic hydrocarbons and nitrogen is great because it keeps the water out and freeze ups during start up to nil and there is no air to purge, love it. Bring in a LIN truck that put up 3000 psi and vaporize to GIN.