For Two Stage Compressor Only

High midstage pressure

Broken valve or blown gasket on the high stage - Replace broken valve reeds or gaskets

Low midstage pressure

Broken valve reeds or blown gaskets on the low stage - Replace broken valve reeds replace gaskets

Economizer/desuperheater connection hot

Broken valve reeds on high stage. - Replace broken valve reeds

Broken high stage gasket - Replace gasket

Intermediate pressure equals the discharge

Center low stage valve plate gasket is blown(typically caused by heavy liquid flood back or flooded start) - Eliminate flood back and replace gasket

Compressor started with discharge service valve closed - Open discharge service valve

High stage valve plate is on the low stage cylinder head. - Switch valve plates so high stage valve plate is on the high stage cylinder head.

Internal relief valve loose - Tighten internal relief valve

Internal relief valve blown - Replace internal relief valve