POA valve testing

[randy500]

Its real easy.
Picture shows flex handle and extension in outlet of valve for adjustment.
The nut is either 7 or 8mm or 11/32, its kind of an odd size.
Pressurize 100psi or so through evaporator with or without expansion valve in place. You will hear a soft pop then the valve should regulate to set pressure, approx 29.5psi for R12 and 27.5 psi for 134a.
Some valves have a honking sound when pressurized and regulating, thats fine but can sometimes be heard when running.
If the pressure is much higher or does not regulate then the POA valve is bad.