R-Pro › Field cases › Components
Semi-Hermetic Reciprocating Reed Valve Failure — Loss of Compression
Likely causes
Reed valve metal fatigue fracture — cracks from long-term repeated flexing
Check: After startup, confirm no suction pressure drop and no discharge pressure rise. Disassemble with head bolts at 25~35 N·m torque, visually inspect valve plate — check for metal fragments, cracks, deformation
What to do: Replace reed valve and valve plate set with OEM parts (verify thickness 0.3~0.5 mm) → lap valve seat with 400-grit sandpaper (flatness within 0.02 mm) → pass N₂ 1.5 MPa 5-min leak test before assembly
Liquid slug shock — water hammer damages reed valve
Check: Check for history of knocking noise at startup. Black carbonized oil indicates repeated liquid slug history. Verify expansion valve superheat (normal: 5~8°C, below 3°C = danger)
What to do: Reset TXV superheat to 5~8°C → preheat crankcase heater 4 hours (oil temp above 40°C) → if oil is carbonized, replacement is mandatory — old carbonized oil will destroy the new valve again
After replacing reed valve, always replace oil too. Carbonized oil = main culprit for re-breaking the new valve. Valve plate assembly torque: 25~35 N·m — beware of over-tightening which deforms the plate.
All 565 cases work offline in R-Pro, with error codes for 62 brands and P-T data for 108 refrigerants.
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