Have a refrigeration loop that cools water/methonal to help bring testing room temp to operating conditions.
We are working with 507R and have adjusted this to around 10 PSI superheat.
This EV is ahead of a DX coil with a solenoid valve in front of it.
Feeler bulb is on suction line after evap with a stepper valve after it. Inlet pressure is about 180 to 190 PSI. suction around 110-120 PSI.
Problem....the top on my expansion valve is mushrooming after a few months of operation. Just changed it out! Looking for a solution to keep the pressure from damageing the valve during off cycle or start up.