On the Importance of Confirming Signatures—the Importance of Bill Handling!

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I. Date: April 26, 2015 II. Location: Unit building III. Participants: Fitter + Instrument technician + Departmental management staff = about 10 people IV. Cause: No maintenance work planned for the previous system; the system was maintained at a pressure of 2.5 Mpa； The temperature sensor for the radial bearings on the low-pressure side of the compressor’s high-pressure cylinder was damaged; a blacksmith removed the radial bearings and thrust bearings in order to inspect them and replace the sensor ； Unit at rest, without air, steam, oil, or power supply ； According to the maintenance plan, the process engineer organized the necessary process procedures: the pneumatic two-position valve at the compressor’s inlet was closed, but the manual shut-off valve (DN300, 600LB) located downstream of that two-position valve remained open. The instrument technician adjusted the pneumatic two-position valve at the compressor’s inlet. The maintenance work order was not signed off by the shift supervisor in the process department; the normal procedure should have been: process engineer – equipment technician – safety officer – process supervisor – equipment supervisor – shift supervisor in charge of processes – person who receives the work order – worker carrying out the work. By violating these procedures and opening this valve, gas immediately entered the compressor cylinder, causing it to start rotating from a stationary state at around 900 r/min ； VI. Sequence of events: Before the incident, 2 fitters were working on the top of the compressor cylinder; after the valve assemblies were removed, 2 more fitters simply secured the shaft. 4 instrument technicians were responsible for removing the signal wires from the edges, while the rest of the personnel provided assistance from the periphery ； The fitter who was coming down from the top of the cylinder block suddenly shouted that the compressor had started running; for a moment everyone was stunned... 7. Result: No injuries were reported, and there was no visible damage to the equipment; strict action will be taken. VIII. Reflection: Safety is no trivial matter; staying vigilant everywhere is a form of education ； Carefulness is an attitude, while diligence is a skill!