PSV for Hydrotesting of Pipes
PSV for Hydrotesting of Pipes
(OP)
Dear All,
What is your experience on hydro testing of pipes.
As far as safety is concern, is putting a pressure relief valve beneficial?
thanks in advance..
What is your experience on hydro testing of pipes.
As far as safety is concern, is putting a pressure relief valve beneficial?
thanks in advance..





RE: PSV for Hydrotesting of Pipes
If it ain't broke, don't fix it. If it's not safe ... make it that way.
RE: PSV for Hydrotesting of Pipes
We will be using positive displacement pump during the hydro test of many test packages. To assure of human error and protect the pipe for overpressure is it not reasonable? On the world of pump if you used positive displacement on the line, psv is mandatory though the fluid is water. As part of the client side on the Ethylene Cracker Plant construction, safety is one of our utmost concern..thanks again..
RE: PSV for Hydrotesting of Pipes
The pipe probably has a range in which it will be tested. The minimum test pressure, to which every point on the pipe must be subjected, and a maximum test pressure, perhaps equal to the pipe's yield pressure. If the PD does have a PSV itself, you should set the PD pump's PSV within that range.
Alternatively, you can fill the pipe with a low pressure PD pump, then switch to quite a small capacity pump, with a discharge pressure rating over test, but under that of the yield pressure of the pipe, if you can. If you can't, the discharge from a small capacity pump, even though at a higher than pipe yield pressure, when running slowly will be disipated within the pipe with enough warning time in advance to stop the pump before sustained pressures higher than yield are reached.
If you only have a giant test pressure pump that you can't turn off, sure install another PSV.
If it ain't broke, don't fix it. If it's not safe ... make it that way.
RE: PSV for Hydrotesting of Pipes
I've done a few dozen tests and not only do I not add a PSV, I've frequently had to remove PSV's set at MAWP when I was testing to a multiple of MAWP. During a test the protections typically provided by a PSV are replaced by human observation.
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.
RE: PSV for Hydrotesting of Pipes
If it ain't broke, don't fix it. If it's not safe ... make it that way.
RE: PSV for Hydrotesting of Pipes
A new jacketed pipe came to site next day. The owner did not.
Good luck,
Latexman
RE: PSV for Hydrotesting of Pipes
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.
RE: PSV for Hydrotesting of Pipes
Good luck,
Latexman
RE: PSV for Hydrotesting of Pipes
If it ain't broke, don't fix it. If it's not safe ... make it that way.
RE: PSV for Hydrotesting of Pipes
Richard A. Cornelius, P.E.
WWW.amlinereast.com
RE: PSV for Hydrotesting of Pipes
If it ain't broke, don't fix it. If it's not safe ... make it that way.
RE: PSV for Hydrotesting of Pipes
Based on your valuable comments the following will be done. Verify pumps maximum input power that will make the maximum pressure output and base on these data, we will be comparing the design pressure of the pipe. If the design pressure is less than the maximum pressure output then PSV will be required. However if the design pressure of the pipe is greater than the maximum pressure output of the pump based on the maximum input power then psv is not necessary.
thank you all...
RE: PSV for Hydrotesting of Pipes
In over 40 years of observing/witnessing Hydro Testing of piping both in service and newly fabricated I've never seen a pipe burst from the calculated test pressure. Testing pressure to 7200 psig to a routine 3500 psig for core pipe in polymer jacketed pipe and 175 psig in the jacket.
We use the following equipment and used the pressure relief/bypass valve on the higher volume requirements. While the Sprague is normally control by the operator. We normally use two gauges a dumb gauge and calibrate gauge for the actual test pressure. The dumb gauge will normally be located on a high point vent. We have a special valve that will allow the venting of air while keeping the gauge in line.
Having said all of the above we did do some burst test on SS and Ally 20 pipe that have lack of fusion and penetration in the long seam.
You can rent about any type pump you need.
http://www.hydratron.com/media/html/hydro_pumps.ht...
http://sprague.cwfc.com/Products/spokes/Pumps.htm
RE: PSV for Hydrotesting of Pipes
If it ain't broke, don't fix it. If it's not safe ... make it that way.
RE: PSV for Hydrotesting of Pipes
My suggestion is that you first look to your design code, standard and project specifications to see their requirements.
Then if you are a consultant, safety officer, or any other side than the Contractor, "ask" (or recommend based on your role)for the safety valve. Depending on the project contract, the Contractor must/may provide it or not but you have your request on the record. If you are on the Contractor side then add this valve as a safeguard against stupidity and to avoid any probable technical/contractual discussions in case of a possible over-pressurize of the pipe. These discussions could convert to legal charges in case of a pipe burst.
you might like not to specify this valve under circumstances that you find yourself.
PS: most of the hydrostatic test procedures ask for some sort of a step-rising pressures with holding times between each step before reaching to the maximum test pressure. This would give a room for finding "weak" points or realizing leakages before a burst under the maximum pressure. You can look to ASME B31 series for some guidelines. ASME B31.1 has no mandate for the relief valve for the hydrostatic test but makes it mandatory when it comes to Pneumatic leakage test "pressure relief device shall be provided, having a set pressure not higher than the test pressure plus the lesser of 345 kPa 50 psi) or 10% of the test pressure."
RE: PSV for Hydrotesting of Pipes