Tell something you know about safety accidents or incidents related to instruments

A simple oil-proof spring-type pressure gauge designed for oxygen would be suitable; oil contamination caused by management issues can lead to instantaneous explosion and melting when in contact with liquid oxygen； Pressure drop due to freezing and blockage of the pressure gauge connection tubes, resulting in sequential shutdown ； Vibration causes short circuits or open circuits in the temperature sensors (thermoresistors/thermocouples), leading to the device shutting down automatically ；

1. During cross-operation in the polymer silo, the instrumentation team was removing valves and instrumentation air ducts; there were people at the bottom of the silo, and one person’s lower leg was fractured as a result of being crushed by the gate valve at the bottom of the silo. 2. A fault occurred at the compressor interlock temperature point; after bypassing it, on-site inspection was carried out. The adjacent circuits were not bypassed, and careful inspection was not performed – measurements were taken on other circuits, which led to a shutdown due to the fault. 3. Check the start relay of the high-voltage motor; use the resistance setting to measure the output circuit to prevent accidental startup of the motor. 4. Inspection of the solenoid valve power supply circuit: During the test for continuity of the circuit, the inner terminal was disconnected (a design change was not applied, and the wrong terminal was disconnected); continuity was checked on the outer side, and the terminals of this circuit were not blown. However, the main fuse on the power supply board was blown (due to an inadequate fuse design), resulting in the shutdown of the equipment and losses of several million. Therefore, the wiring for testing the circuit must be connected and disconnected on the inner side, with measurements taken on the outer side (while the system is running) ； During the engineering phase, all changes must be updated in the final set of drawings.

During the pressure gauge replacement task, since the inspection label on the gauge covered the unit indication, the employee didn’t pay attention and installed it with KPA instead of MPA. The pressure gauge burst the day after tomorrow after replacing it and opening the valve

I can’t remember whether it was 2017 or 2018; the video showed two workers performing maintenance on a reactor. The worker on the left was using a wrench to carry out the work, and for some reason, a plume of fire erupted (similar to that seen during a space shuttle launch). It all happened in just one second – the workers disappeared instantly, with only a few pieces of clothing falling to the ground.

A long time ago, an instrument technician from a company was performing maintenance at night, with no supervision from process engineers or any other instrument technicians; he worked alone and suffered from hydrogen sulfide poisoning. It was not discovered until the shift change the next day in winter, by which time the person had already passed away. I hope colleagues will take this as a warning to carefully consider the conditions on site before working, to avoid dangers, and to try to have someone supervise the work. For small companies that do not have enough instrument technicians, it is still necessary to have a process engineer supervise the work before starting. I hope all instrument technicians remain healthy and safe