System Leak Test

How often do you all test for system leaks? What is an acceptable leak rate of your system or is zero the only acceptable result? Are you leak testing because of a regulator or because it is just good practice? :face_with_monocle: Thanks!

edit: what pressure also is helpful.

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Both, leaks =problems one way or another

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No leaks are acceptable, and I try to test prior to every run. (not for licensing, for best practices)

Run butane only, so pressure test to 100psi for a couple of hours.

If it’s a newly assembled piece, I’ll pressure test for 24 hours.

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@Curious_miner Are you looking for the pressure on a gauge to go down? Is that why you are doing it for so long?

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Correct, I have a numerous psi gauges I have in my system. I’m checking for any kind of psi drop at all.

I’ve found small drops that I couldn’t find for the life of me when I built new pieces that didn’t show up after a couple of hours, but overnight they did. I’d rewrap and retighten things and test again

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This method is called a “pressure decay” method for leak detection.

edit: spelling

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i like to run a full hydrostatic test to a few hundred psi.
it cries out the weak spot when then pressure is too much.

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So you look for water leakage in places?

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it is very obvious and gentle even past 500psi.

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How long will you hold pressure before you are satisfied there are no leaks?

What are your tri clamp sizes are you using? Because anything above 6in is not even rated for 500 psi, that’s a ton of pressure.

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We test with nitrogen because of its small molecular size leaks that would not otherwise be present will show every slightly

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When running with nitrogen are you holding for a period of time and watching the pressure drop or some other method of reading a leak? Do you then use a sniffer to find the leak in your system?

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Soapy water in a spray bottle will tell you where its coming from if you pressurize the system with nitrogen, air etc.

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Agreed. But do you go looking around for the leak before you know you have one? Or do you watch say a pressure gauge drop over some period of time before going for a hunt.

Also, Simple Green works best as a soapy water to find leaks. Or you can use Snoop by Swagelok.

500psi does seem pretty excessive…like scary excessive.

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If your system is all stainless it might be able to handle this without a problem.

Edit: Let me clarify so i don’t get anyone hurt…
I say it should not be a problem based on a PE review report done on a common CLS stainless system. In that particular system it could ONLY handle 250 PSIG if the unit had a site glass, 560 psi circumferential stress and 1100 psi for longitudinal stress in the 5" tank. In the 6" dia vessel it was 450 psi and 919 psi respectively.

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500psi i can trust propane going wild in there.

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I use nitrogen, I pressurize the system. I dunk the collection in a bucket…look for bubbles. Let the system sit for a while, no drop on the gauge, I’d roll with it assuming you know your equipment to be good. If there was a drop on the gauge, I would increase the pressure, as to generate a larger volume leak, and apply soapy water.

It’s basic problem solving and diagnosis. Is there a leak…yes or no? If no, proceed. If yes, locate with bubbles.

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Oh snap. Full propane huh…I’d like to try that on my system sometime. How high have you seen it get in operation? Surely not near 500psi?

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