Control Devices VR38-100 VR Series Brass Vacuum Relief Valve, 0-30" Hg Vacuum Range, 3/8" Male NPT

I like that it is adjustable.

Only one i will ever use and I looked! all over the state (marine,plumbing,hvac,tank,pool,fuel systems) brass body, good npt threads, good adjust threads, o ring seal stainless spring, and is appropriate size, most are some steel over plastic and have to high stack height - this is 1.5" good size for marine water, and fuel tanks, or any tank size with reasonable draw rates; even has seal compound preapplied on npt. i do not comment much or usefor hyperbole. I may by another just because it was such a relief to find one, with good height, function, and machining after going crazy for hours lookingI just purchased another one for future job, and to say it is so cool to be able to buy good valve applications.

Used to regulate the vacuum on a screen printing exposure system - allows just enough relief to help extend the life of the pump as well as not put the blanket through necessary stress and stretch.

Had no issues with the red rubber on the threads, wrapped some teflon tape, screwed it into my pvc vacuum reservoir and I can adjust the vacuum from 0 all the way up to about 23" Hg. This is exactly what I've been looking for to regulate the vacuum on my bagging machine I use to make r/c aircraft wings. Absolutely love this, now I just hope it lasts:)

Does what it claims. Easy adjustment and lock. Silent operation. Great product.

Use it to set my home made goat milking machine to 10" vacuum, works perfectly

So far I have not seen it work. I have it on a still and when the still cools the top sucks in a little and this does not seem to relieve the vacuum. It says 0 to 30 hg so it should work with very small amount of vacuum.

This was a perfect match for my project. Did exactly what I needed, thanks amazon!

J’ai commandé par 2 reprise ce produit dans la grandeur 3/8 et à chaque fois j’ai reçu 2 grandeur différente. Une de 3/8 conne prévu et l’autre de 1/4 .