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China Accident Investigation Report No. CN-MEM-2014-07-08 2014 Toxic release Toxic
Qingdao Qichao Cold Storage Refrigeration Compressor Liquid Ammonia Leak Accident ('7-8')
Qingdao Qichao Cold Storage (Chengyang District Work Safety Administration investigation report)
Related equipment → Reciprocating compressor (recip_compressor)
0Fatalities
1Injuries
LeakageMechanism code ELP
⌗Failure Mode · ISO 14224 Mapping
Damage mechanism (recorded in KB)
LeakageELP
ISO functional code (as recorded)
ISO 14224:2016 functional failure code
ELP · External leakage - process
ISO ELP — External leakage - process.
1What Happened

Refrigeration compressor shaft-seal gland asbestos O-ring gasket aged and lost elasticity + loose fastening bolts -> liquid ammonia leaked through shaft-seal crack

2Root Cause

Compressor components not maintained in time (gasket aging); operator refrigeration error (intercooler overpressure, liquid ammonia returned to cylinder); unsafe emergency handling; weak safety management and training, shutdown order not enforced

3Reliability Lessons (from investigation root cause)
  • The 'Root Cause' above is the core lesson of this accident; not split further.
4Associated Failure Mechanisms (Keywords)
reciprocating compressor refrigeration compressor shaft seal O-ring liquid ammonia seal failure bolt loosening overpressure liquid return
About the Failure-Mode Code (click to expand)

The recorded code ELP is an ISO 14224:2016 functional failure code (describes what the equipment failed to do). The damage mechanism (how it failed) is shown in the Mapping block above. The two are distinct dimensions in ISO 14224.

5Evidence Source (transparent)
Authority：Chengyang District Work Safety Supervision Bureau (China industrial accident investigation system)
Official Report：www.chengyang.gov.cn ↗
Data Verification：verified_url_chengyang_gov_cn_2026-07-20
↗Related Failure Modes · Traceability
密封端面磨损 COMP-C3-FM2Valve Plate Fracture valve_plate_fractureValve Seat Leak seat_leakSpring Failure fmRing Wear ring_wearPiston Rod Fracture rod_fractureLiner Wear liner_wearPacking Wear Leak fm_2Fatigue Fracture fm_3Journal Wear fm_4Connecting-rod Bolt Fracture fm_5Babbitt Bearing Wear / Flaking fm_6Tube-bundle Fouling fm_7Tube-bundle Leak fm_8Level Control Failure fm_9Lube-oil Pump Wear -> Low Pressure fm_10Filter Blockage fm_11轴封泄漏（工艺气） shaft_seal_leak_gas密封失效 MECH-SEAL-FAILURE
Report No. CN-MEM-2014-07-08 · Data from China Emergency Management Dept. public investigation conclusions, compiled by Reliability AI, for reliability demonstration purposes only. This case is derived from public incident investigation reports for learning purposes only. AIM does not endorse or guarantee its accuracy.