Hydrotest of multiple valve
Hydrotest of multiple valve
(OP)
Hi,
Is there any restriction in hydrotesting of multiple valves connected in series to meet ASME B16.34. We have 200+ of globe valves to go for hydrotesting, to reduce the test lead time we are thinking of connecting 5 valves in series and test them at the same time using test pressure and duration required by ASME B16.34
Regards,
Habas
Is there any restriction in hydrotesting of multiple valves connected in series to meet ASME B16.34. We have 200+ of globe valves to go for hydrotesting, to reduce the test lead time we are thinking of connecting 5 valves in series and test them at the same time using test pressure and duration required by ASME B16.34
Regards,
Habas
RE: Hydrotest of multiple valve
The key here is to find quick way to fixture the valve for testing.
RE: Hydrotest of multiple valve
From which stand point are you? manufacturer or site installation?
In short there is no restriction.
Hydrotest consist of two things closure and seat test.
Closure or body test is quite straight forward, 1.5xMAWP, for testing period given in API 598/ISO 5208/API 6D, if there is no leakage then it should be alright.
For seat test is a bit tricky, since you can only measure the leakage from the farthest end (outlet of your 5th valve). And if you find leakage on any valve then you have to drain all or add more water before testing the next one. In the end the result is quite vague since you don't know for sure which one is failing, takes time to stabilize pressure and takes time to add water and purge pressure.
Agree with TugboatEng, you may need to re-test the batch. Even manufacturer which can produce 100+ valves per day still do this one by one, with harmonious testing process. Such as quick clamping mechanism and more than sufficient amount of water readily available.
For this reason, under a very restricted amount of schedule or for some other reason, maximum so far I saw is three valves in series.
Regards,
MR
https://nosuchvalve.com
All valves will last for years, except the ones that were poorly manufactured; are still wrongly operated and or were wrongly selected
http://www.eng-tips.com/faqs.cfm?&rat1=2&f...
RE: Hydrotest of multiple valve
luis
RE: Hydrotest of multiple valve
i've never hear of a job site trying to test 200+ globe valves at once, so I think this is a supplier/manufacture case. I wouldn't do it, use a test stand.
Luke | Valve Hax
RE: Hydrotest of multiple valve
Danlap, I am referring to shell hydrotest and not the seat test.
I read through ASME B16.34, API 598 & EN12266 and couldn't find any restriction.
API598 and I quote "Except as provided in 6.2.2, the shell test shall be made by applying the pressure inside the assembled valve with
the valve ends closed, the valve partially open, and any packing gland tight enough to maintain the test pressure,
thereby,
En12266 "The end connections of the shell shall be blanked off and all cavities filled with the test fluid"
So, as long as the first end of the valve & the last end of the valve in series connection is closed during the duration of the test, I should be OK.
But I agree, the tricky part will be , if 1 unit fail from 1 series and I have to test the rerest of the valve.
Habas
RE: Hydrotest of multiple valve
Yes, it is a common practice to (shell) hydrotest the piping with multiple valves (even more than 5) at 1.5 MAWP. Especially when (new) welding connections are presence.
Good that you quote API598, my advise is not to loosen the gland packing. Just keep it as is, and open the valve.
Success with the hydrotest.
Regards,
MR
https://nosuchvalve.com
All valves will last for years, except the ones that were poorly manufactured; are still wrongly operated and or were wrongly selected
http://www.eng-tips.com/faqs.cfm?&rat1=2&f...
RE: Hydrotest of multiple valve
some cases would change that odd.
1) temperature difference, or soft seal failing due to installation, think ball valves which relies on o-ring for primary seals, failing due to too cold or too hot temperature once in line. ( you have globe valve, this does not apply)
2) blast beads destroying stem seals
In fact, if you want to do pre installation check, my recommendation is to fully stroke the valve open, inspect the stem on the globe valve for damage and external debris in packing gland area, inspect gland torque, and return to original position, as well as double check raise face or other facing condition (follow 16.5 imperfection guideline). this activity will worth the cost and effort.
Luke | Valve Hax | https://valvehax.com/
RE: Hydrotest of multiple valve
If I was a manufacturer, and someone from a site called me and said a valve was leaking or damaged, and that they had pressure tested the valves, the conversation will quickly change to how the valves were tested and how much the site installer is going to pay to get the valves fixed.
If you are going to do this regardless of this advice, and the advice from HitokiriAoshi, it would be wise to contact the manufacturer and follow any instructions they provide.