Reciprocating refrigeration compressor shaft seal leakage diagnosis, replacement and oil retention control

Reciprocating refrigeration compressor shaft seal leakage diagnosis, replacement and oil retention control

Shaft seal isolates crankcase lubricant from atmosphere; shaft seal failure causes oil leakage or air ingress, which will contaminate lubricant and reduce vacuum performance. Visible oil dripping exceeding 5 drops per minute is defined as severe shaft seal leakage; air ingress through damaged shaft seal will raise system non-condensable gas content rapidly. Xiteliduo reciprocating compressor adopts spring-loaded mechanical shaft seal; shaft displacement exceeding 0.04 mm will accelerate seal face wear and trigger leakage. Small 4-cyl reciprocating refrigeration compressor shaft seal damage often occurs after long standby; static seal face adhesion happens during shutdown period. Medium 4-cyl reciprocating refrigeration compressor shaft seal leakage may be induced by crankcase pressure surge; frequent pressure shock damages seal contact surface. Large 4-cyl reciprocating refrigeration compressor shaft seal cooling relies on circulating lubricant; oil supply interruption will cause seal face overheating and thermal cracking. Large 6-cyl reciprocating refrigeration compressor crankshaft slight runout will concentrate friction on partial shaft seal surface; local wear gradually develops into leakage path. Many maintenance operators only replace shaft seal when oil dripping appears. Early micro leakage without visible drops increases oil oxidation speed by 38%. Single-unit two-stage refrigeration compressor low-stage shaft seal works under suction vacuum condition; damaged seal allows air to suck into refrigeration circuit. Cascade unit high-stage reciprocating refrigeration compressor shaft seal bears high crankcase temperature; high temperature hardens sealing rubber and shortens service life.

FAQ

Q1: What dripping rate is regarded as severe shaft seal leakage of reciprocating compressor? A1: Oil dripping more than 5 drops per minute is severe shaft seal leakage. Q2: What shaft displacement threshold will accelerate Xiteliduo mechanical shaft seal wear? A2: Shaft displacement over 0.04 mm speeds up the wear of seal faces. Q3: Why may small 4-cyl reciprocating compressor shaft seal fail after long shutdown? A3: Static adhesion occurs between sealing faces during standby time. Q4: What factor may damage medium 4-cyl reciprocating compressor shaft seal contact surface? A4: Repeated crankcase pressure surge and shock load. Q5: What is the cooling medium for large 4-cyl reciprocating compressor shaft seal? A5: Circulating lubricating oil provides cooling for shaft seal assembly. Q6: What consequence will invisible micro shaft seal leakage bring? A6: It accelerates lubricant oxidation by 38%. Q7: What problem will damaged low-stage shaft seal cause for single-unit two-stage compressor? A7: Air is sucked into the refrigeration system under suction vacuum.