FTC承包商误拆柱塞阀压力保持螺栓（本为拆执行机构）→阀塞弹出，164,000 磅 238°F 醋酸混合物喷出，2 死 2 重伤
阀门设计未防人误拆（同类事故重复发生）；无拆卸程序与培训；承包商与公司均未识别风险
The mechanism code FTC shown on this card is the KB's internal damage-mechanism abbreviation (not an ISO 14224 code); it describes how the equipment failed. The 'ISO 14224 Mapping' block above maps it to the correct ISO functional failure code (which describes what the equipment failed to do) — these are two distinct dimensions in ISO 14224. The mechanism follows the narrative in the card body.
fmValve-seat Surface Damage -> Internal Leak fm_2Valve-plug Erosion fm_3Valve Stem Sticking / Bending fm_4Packing Wear -> External Leak fm_5Diaphragm Rupture fm_6Spring Fatigue / Fracture fm_7I/P Converter Failure i_pFeedback Link Loosening fm_8Coil Burnout fm_9Valve Plug Sticking -> Failure to Actuate fm_10Contact Corrosion / Poor Contact fm_11Filter-element Blockage -> Insufficient Supply fm_12Pressure-Relief Valve Set-point Drift fm_13内腐蚀（Internal Corrosion） internal_corrosion外腐蚀（External Corrosion） external_corrosion保温层下腐蚀 CUI（Corrosion Under Insulation） cui冲蚀-冲刷腐蚀（Erosion-Corrosion） erosion_corrosion死角/滞留区腐蚀（Dead-Leg Corrosion） dead_leg_corrosion热疲劳（Thermal Fatigue） thermal_fatigue振动疲劳（Vibration Fatigue） vibration_fatigue应力腐蚀开裂 SCC（Stress Corrosion Cracking） scc氢致开裂 HIC（Hydrogen-Induced Cracking） hic脆性断裂（Brittle Fracture） brittle_fracture高温蠕变（High-Temperature Creep） creep法兰-垫片密封泄漏（Flange/Gasket Leak） flange_gasket_leak焊缝缺陷/未熔合（Weld Defect） weld_defect水击（Water Hammer） water_hammer堵塞/沉积（Blockage/Deposit） blockage机械损伤/第三方破坏（Mechanical Damage） mechanical_damage阀座工艺介质泄漏 seat_leakage_process阀门卡涩（机械卡阻） valve_sticking_through弹簧松弛整定漂移 spring_relaxation_setpoint_drift喉部冲蚀 nozzle_erosion阀盖泄漏 bonnet_leakage整定压力错误 improper_set_pressure异物堵塞 foreign_object_blockage起跳颤动 chatters_on_lift选型过小排量不足 sizing_undersized结垢/堵塞 MECH-FOULING均匀/局部减薄（通用减薄） MECH-THINNING机械疲劳 MECH-MECH-FATIGUE脆性断裂 MECH-BRITTLE-FRACTURE