Thanks Rocket
For an update for me that a Copeland Engr states 5 psi on the crankcase check valve instead of 1/2 psi. Can you help me with the same psi information on a Carlyle? Why is the check valve there? Is it to flash off the liquid refrigerant out of the oil or prevent the oil from backing up out of the crankcase into the motor cavity?

I'm still learning at 55