Adjustable pressure relief valve

Anyone have any experience with nai-lok adjustable pressure relief valves? Just trying to figure out how to set pressure.

Yep. You turn the cap to adjust & use nut to lock it when you get there.

Done installed and under pressure…,

Or get thee some Swagelok
Then rtfm…

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ahhhh yeah, love them swagelocks!
The datasheets for their products are spot on, and you can order valves that don’t contain any lubricants. Most people don’t relise how dirty generic valves are, especally when swagelock offers components that have undergone “special cleaning & packaging”.swagelok special cleaning.PDF (99.0 KB)


I pull black q tips after solvent washes eveytime!!!
Black I SAY!!!

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ohhh, what valve?

any new ss parts I clean w acetone…dip q tip In acetone cleaning insides parts till black stops

Oh, yeah. I have noticed that, I think it is the reminents of some polish they use. I pitty the fool who dosen’t wash their new ss parts before extracting with them. (read in Mr.T voice)


When setting a nai-lol stainless steel PRV, is the only way to know what pressure you have set it to is to charge it with nitrogen and observe where it cracks pressure?


thats the only accurate way. I set my prv with a little handheld pneumatic regulator with guage. start at 0psi and work up until it releases pressure. then see what the gauge reads and thats it release pressure.


then you should also figure out where they re-seal…

once the system holds pressure, take it up till the prv’s pop, record that pressure, and then watch where it settles. do it a couple of times to make sure.

if you’ve got multiple PRV’s, isolate them, and check them independently.