On 6/16/2016 10:44 AM, Frank wrote:
replying to trashmanvic, Frank wrote:
I also have a McDonald 75lb pressure valve between my pressure tank and the
line into my home. It just partially failed. I tightened the top screw (tho'
the McDonald literature says not to adjust in the field, they are preset at
the factory). Now my 40/60 switch kicks off at precisely 60lbs, as it is
supposed to. But the in-line pressure gauge shows the pressure in my line
continuing to rise (AFTER the pump stops) to 70-72 lbs. Did you find a
solution? PLease share, if so. Thanks

Turn off your water heater, let things equilibrate, then repeat.

(As water in the water heater is heated, it expands into the "cold" water
supply. Without an expansion tank, water pressure can *rise* 50 pounds!)