Do I need to remove the nearby automated instruments when welding?
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The last time a pipe was welded, the mechanic carried out the welding directly without removing the thermocouple located near it. Once the welding was complete, the PLC’s thermocouple module was damaged. The thermocouple module was working fine when the machine was shut down, but the PLC started giving errors after it was repaired and powered back on. Recently, I welded another piece of equipment. There was an electromagnetic flow meter 2 meters away from the pipeline. The technician thought it was too troublesome to remove the flow meter, so he proceeded with welding without taking it out first. After powering on the flow meter, it failed to display any values. From these two incidents, I realize that it’s essential to remove any automated instruments located in the vicinity during welding, otherwise those instruments are likely to get damaged. I wonder if anyone else has encountered similar situations; I’d also appreciate any analysis you might have
It mainly depends on how the welding machine forms the circuit; as long as the current does not pass through the meter during welding, there is no problem. It’s similar to why a bird standing on a high-voltage wire isn’t electrocuted – electricity has a tendency to take the shortest path.
When using a welding machine with two wires for welding, there is no problem as long as the instrument is not connected in series with the grounding circuit; however, more sensitive instruments can still be affected.
This does happen; the key is to ensure proper grounding, and it must not be connected casually to pipes
Before welding, the electromagnetic flowmeter was functioning normally; all welding locations were beneath the flowmeter. The distance from the first weld site to the flowmeter was around 30 centimeters, while the distance from the second weld site to the flowmeter was about 1.5 meters. The welding ground wire was placed about 1 meter below the flowmeter. After welding, there was no flow indication on the flowmeter, nor any output in the 4-20 milliampere range. I think this was caused by the high current generated during welding. Later, when I asked the mechanic on site, he said the current level was 170A
Comrades, you’ve all forgotten an important issue: heat conduction. If the welded pipes are connected directly to the instruments and at a short distance from them, it’s possible to damage the instruments. Don’t ask me how I know; it’s all because of the tears :(
If possible, contact them for removal; a previous high-precision mass flow meter was damaged due to welding
You’re also having this problem, so it seems I’m not the only one facing it
During pipeline welding, there are two ways in which instruments can be damaged. One is damage caused by the high current during welding passing through the instrument (some people claim that as long as the instrument is not part of the welding current circuit, it won’t be damaged, but how can one be sure that the welding current won’t pass through the instrument?) (The reason is unclear); another issue is that the high temperature generated at the welding points can damage instruments that are too close to them.
Okay! Well done welding! The old watch is fine; the new one hasn’t arrived yet. Using a new gauge can be great – just like having a new bride; it’s really impressive. I guess high-frequency spikes are generated during welding, and these spikes damage the microcontroller in the instrument…… Before 1990, microcontrollers were extremely sensitive to such issues, making them very difficult to use. It was around 1994 that the ability of microcontrollers to resist electromagnetic interference improved significantly, which led to the rapid development of smart instruments over the years…… At present, the microcontroller remains the weakest link in smart instruments. Compared to operational amplifiers, microcontrollers are still quite weak and not as reliable. :P
Bro, that smug look of yours:Q. Really though:@. But your analysis later on is quite solid; giving you a thumbs up:P