Hey all. I have a pressure guage on the supply line to my hot water heater. It is registering a static water pressure of 120 psi, but when I open a valve, it drops to 45 psi. I read that a dropoff of 3-12 psi is normal with the Honeywell Braukmann D05 which I have, but this swing of almost 80 psi seems steep. I am worried that over time the pipes will fatigue. Does anyone know if this sounds like a problem with the pressure regulating valve? Thanks for any advice.