Hydrostatic test 7

[kenwk]

Does anyone have a hydrostatic test procedure and what type of equipment is used?

 

[TGS4]

Does anyone have a hydrostatic test procedure?

Yes

What type of equipment is used?

Some water, a pump, and a pressure gauge. And, of course the equipment being hydro-tested.

Now, if you actually have a question, and are not just looking for someone to do some free work for you, please ask a real question.

 

[racookpe1978]

What if he doesn't want to use water?

Can he hydrostatically test with something else if he wants to?

Or - if the something else - gets hot and blows up - does that make it become a hydrostaticaerodynamically test?

 

[kenwk]

Do I need a special pump? Or can I fill the tank with water and connect my air compressor(or compressed gas i.e nitrogen) and apply the required pressure?

 

[vesselfab]

ohhhhh geeeezzzus

please publish date and location of test

so i won't be anywhere near there.

any pump that will reach the desired pressure will do

gas in a hydrostatic test is a no-no

pnuematic test or combination hydrostatic/pnuematic is allowed if you know what you're doing.

do you have a hydrostatic test procedure in place?

pressurized gas stores a lot of energy parts can be found far away if an accident happens.

 

[brandonb73]

We use a portable pressure washer for field hydro's. But be very careful, they can generate up to 3000 psi. You can also get hand pumps if your vessel is small.

Your procedure should include:
1. Test medium
2. Test pressure
3. Temperature range
4. Pressure gauge range requirements and calibration
5. Hold time
6. Acceptance criteria

The ranges for these can be found in whatever code of construction or repair you are using to build or repair this item.

Double check the code of construction, but the pressure gauge range should be approximately double the intended test pressure, not more than 4 time and not less than 1.5 times.

Hope this helps.

 

[moltenmetal]

vesselfab: I hear your frustration, but "any pump which will generate the required pressure will do" conjures up unpleasant images of huge pump connected to small, improperly vented pot...

It's possible, though not preferred, to use the "air over water" method to generate pressure for a hydrotest if you don't have a suitable pump. This does make the test less sensitive and more hazardous- a proper pump, used with a well considered procedure, is safer AND better. Keep the volume of compressed gas under test as small as humanly possible, as the hazard of the test is directly proportional to P x V of the GAS.

 

[MJCronin]

Also..... no one has mentioned how much fun it is to hydro test plastic and FRP systems.

For more laughs, fun and surprizes than a houseful of pipefitters - try a hydro on non-metallic systems..!!!!

Tell your friends !!!

Be sure to have any expendable staff stand near "things of large diameter" during the test.....

-MJC

 

[MJCronin]

Pressure testing using gas can be special fun..

The Chinese found this out a couple of months ago...

http://webwormcpt.blogspot.com/2009/03/pneumatic-test-explosion-in-shanghai.html

-MJC

 

[vesselfab]

YES MOLTENMETAL

I know what you mean, one stroke of a fair size pump can over pressure a small part.

Every now and then we have to dig out the old hand pump to test a single spool.

it's a pain, the check valve leaks back and we have to shut off the gate valve quickly to maintain pressure. One of these days gonna have to fix the old antique, but, when you only use once every 2-3 years.....

 

[racookpe1978]

I, too, would like to be someplace else when this tank is pressurized.

Far, far someplace else.

 

[brandonb73]

Pardon me, but I would like to comment on some of the condescending remarks made about this question.

Do none of you remember when you didn't know the first thing about a hydro test either? Does it make you feel smarter to embarrass the author of this post? People including myself post questions and comments on this forum to collaborate with people that have more experience or different perspectives than our own. By posting a question we are already showing vulnerability, acknowledging that there is something we don't understand. It is therefore not helpful when people make jokes and snide comments.

People should not be afraid to ask questions on this forum for fear of ridicule. People who are afraid to ask questions end up making mistakes. Sometimes those mistakes are catastrophic.

I respectfully request that if you don't have anything helpful to add to a particular thread, then please don't waste your time.

 

[TGS4]

It's not the lack of knowledge or "elementary" questions that draw ridicule. It's the lack of doing ANY work prior to coming to ask for help that gets the condescension.

For example if the OP would have done a little bit of homework, such as a Google search, particularly of this site, then they would have found the answer to their question, or at the very least, been able to frame their question in a much better manner.

We all started out knowing very little. However, through a little bit of self-directed research, many of us have become the engineer that we are today. Eng-tips is not a forum for spoon-feeding any one. Show a little bit of initiative, an indication that you have thoroughly researched a problem, and if are still stumped, you are very welcome to ask a good, thought-provoking question.

Clueless questions, or "I don't want to do the research, please tell me what I need to know" questions will continue to receive healthy doses of ridicule and condescension.

 

[IFRs]

Some of us enjoy teaching others humility. Others move on to more productive threads.

 

[berkshire]

I would sooner see a poster ask a stupid question on here than do a stupid act.
As an apprentice I got blown 20 feet across a shop by an air over hydro test that failed, resulting in a welded seam opening in a tank.
At that time( 1959) there was no Internet to post a question like the one the original poster asked, you relied on the common sense of the engineers and journeymen who were your mentors.
None the less it would not hurt the OP to at least hit Google first before asking here.
B.E.

 

[grantak]

I was always taught, and in turn dictatate to all my people, there are no stupid questions, only stupid answers.

I understood this to be a professional forum.

 

[MJCronin]

Amen TGS4.....

 

[TGS4]

grantak - This wasn't a stupid question, just a completely poorly thought-out question that really needed to be researched and a very small amount of thought put into it before posted.

It's the lecherous nature of these poorly thought-out and very poorly researched questions that prompt the above-noted ridicule.

I have tonnes of time for folks who need assistance (e.g. "Where would be the best place to start researching about hydrostatic tests?"), and then if they are confused by a reference, asking here for clarification questions (e.g. "In XXX, it discussed using a YYY pump for pressurization of the system for hydrostatic test. I've search the internet for information on this pump, but can't find our why it's preferred. Why is this pump preferred, and what are people's experience with other types of pumps?).

Perhaps it's worthwhile re-posting the "Rules" for posting on an internet discussion forum, again...

http://www.eng-tips.com/faqs.cfm?fid=376

http://www.catb.org/~esr/faqs/smart-questions.html

 

[CodeRef]

See ASME PCC-2–2006, PART 5, EXAMINATION AND TESTING, Article 5.1, Pressure and Tightness Testing of Piping and Equipment.
This Article provides general good practice for determining the type of test, the test pressure, and the procedure for pressure and tightness testing of pressure equipment, including tubular heat exchangers, pressure vessels, and piping systems.
Note that this is a general guideline. Follow the appropriate Code requirements applicable to the system you are testing and do whatever research to further your understanding of the dangers involved.

FAQ731-376