How to find a Water Pressure Release Valve
Your pressure relief valve (let's stop using acronyms) is probably located on your water heater, it is actually a temperature/pressure relief valve. Sometimes a "pressure only" relief valve will be located on supply piping also. They are designed to open up and relieve pressure due to an unplanned temporary high pressure event, they both look something like this:



A pressure regulator is different. It is designed to regulate (control) your water utility company pressure before that pressure can damage your plumbing. This is the device you need go find. It should look something like this:



You will notice by a close look at the pictures that these two valves look very different.