Control Devices ST25-1A100 St251A100 St Series Brass Soft Seat Asme Safety Valve, 100 Psi Set Pressure, 1/4 Male Npt

I tested the three I bought, and they all opened at the rated 100lbs, and dumped the air pressure down to 50lbs, when the valve closed. Very pleased with the quality.

I used this to bleed excess air from my compressor setup for my Airlift air bags in my truck. The airbags are rated for 100PSI max, so this prevents my compressor from overfilling them. Right at 100PSI it starts going off. It's loud, but it does the job. I also like that you can attach a key ring to the end of it and bleed the pressure manually if you need to.

My old relief valve would pop off early. Thiss fixed it.

Easy to install, works great. Only drawback was the pull ring is cheap and doesn't hold up. Replaced with key ring and all is good.

This so far, is a dependable air compressor part. Highly recommended.

Happy my really old 50s compressor works. The valve was functioning to 30psi and I thought it was on its way out. This valve works great but only up to 80 something psi. It’s not adjustable and should be 100 psi. Maybe for my sake at 80 psi it won’t blow up!

I have this on my compressor and when it blows you need to have ear plugs and then it lets so much air out that it takes forever for the tank to fill back up. 1/2 hp compressor with a 7.5 gal tank.

The 100psi unit I received starts releasing at 83psi. The device I am supplying air to needs 85 minimum/ 110 maximum. Was hoping to set the regulator at 90psi and have this as a failsafe.It appears to be well made. Did not find a way to contact the seller through Amazon website.