Seems to work great! I had it set at 75, and it didn't leak at 50PSI. The spring loaded design looks like this design should be fairly robust and fool proof. I heard that it leaked for some people, but my application didn't. I used thread tape and never opened it all the way up, so it seems to work for me.

I bought this to install on my steam sterilizer. The sterilizer reaches 121°C (250°F) and 15-18psi.

I obviously have an additional safety release valve and a pressure gauge. The markings on the adjustable valve seem to be within the stated tolerance. It does occasionally get stuck closed. I learned it is best if I open it completely to vent before building pressure and then adjust it when the desired pressure is reached to allow very minimal venting. It never gets stuck if this is done. It always closes and does hold a vacuum upon cooling. All in all it does exactly what I want. I may replace it soon with the same valve simply because it is cheap and for peace of mind.

4/5 for overall quality
5/5 for quality at low price

Use to make a DIY spunding valve for my fermenter. Need to over-pressurize then reduce pressure to get to where you want it, but otherwise works exactly as I would have wanted.

Works as intended though I would have liked it to have more measurements for further calibration, this you'll stil need a psi gauge for proper measurement.

It relieves a fair amount of pressure. I believe more expensive valves relieve more pressure if that is what you need. Overall, it works pretty cool so far for what I use it for. Ignore the numbers used for measuring on this item. It's only there to make the item more attractive to buy. I had to buy a nut for mine in order to install it, which wasn't very hard. I use mine along with a pressure gauge on a homemade low pressure 55 gal steel sterilizing/pasteurizing drum. I never allow the tank to exceed 2 psi. I use this item basically to begin relieving pressure when the pressure reaches 1-1.5 psi. I adjust it according to my pressure gauge. It is most useful to me really in that it is an alarm for me to turn the propane down or open more wide the main relief valve. And I'm sure it helps prevent the psi from exceeding the point that it is set at. I do believe that if I turned the propane all the way up that this pressure relief valve would not be able to prevent my tank from exceeding the 2 psi that I am able to set it at. This is not a proven fact because I have not tested it. I'm just judging by the amount of pressure that this valve actually relieves. It relieves enough pressure that I don't try to find a better relief valve. But if I wanted to be perfectly safe i would wish for a valve that relieves more pressure so that to be sure that it would be impossible to exceed the 2 psi mark that I can set it at using this valve.