On my water pipe system, there is this bell shape thing with a bolt on the top. I always thought it a water pressure regulator.
The other day, the engineer of my community came to check my water system. He said that thing is not a water pressure regulator but a water pressure reducer. According to him, a water pressure regulator is a device that would keep output water pressure constant. If the outgoing water pressure is set to, say, 50, no matter what the main pressure is, be it 100, 90, 80, or 70 psi, the output is always 50 psi.
A water pressure reducer, according to him, is a device whose output pressure is affected by the input pressure. If the main pressure is, say, 80 psi, and the output pressure is set to 50 psi, when the main pressure is increased to 100 psi, the output pressure would also increase.
Does he make sense?