Merrill MFG 3/4" Lead-Free Brass Pressure Relief Valve – 100 PSI Water System Safety Valve, NPT Thread, Durable Corrosion-Resistant Design for Well, Plumbing & Irrigation Systems

Well who knew these things should be inspected yearly and replaced after 10 years. They stop your pipes or water heater from going boom splash. This one is for cold water only and was fitted to our pump. In the event that our filters get blocked it lets the excess water pressure out preventing the above mentioned water disaster. We had to buy a different version with a test handle for our hot water heater.

When I replaced my 40+ year old well pressure tank I added this, which I believe is now required by code. I added an adapter so I can attach a standard garden hose to deal with any outflow.Hopefully this will never be needed but it's reassuring to know my crawl space won't flood if something goes wrong.(Note: for me, 3 stars is not a "bad" review. It just means the product does what it says. 4 stars is "better than expected", and the rare 5 stars is for "surprises and delights with how good it is". I wish more reviewers followed this instead of giving 5 stars to any product that simply works and isn't broken.)