How should the grounding and shielding wires of a mass flow meter be connected?
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The mass flow meter is installed on the pipeline, and the meter itself should be grounded through the pipeline. But the pipeline is so long that no one knows whether there will be welding on it; and if there is welding, could it cause the instruments to get damaged? If you don’t want to use piping for grounding, how can you separate it from the piping? Both the transmitter and sensor of the flow meter have grounding bolts. We usually attach one end of the shield wire to these grounding bolts for shielding purposes, while leaving the other end untied. I’m not sure if this approach is correct
I really hadn’t paid attention to this issue. There’s **below; go and learn about it*
When welding is carried out after the instruments have been installed, there is a high risk of damaging them; not only the flow meters but also other instruments can be damaged； This has nothing to do with how it is grounded; the instrument does not allow wiring the welder in parallel. It is recommended to pre-make the splices according to the specifications of the flow meter; the instruments should be installed only after all the equipment has been installed, the pipelines have been purged, and pressure testing has been completed. If this cannot be done, it is very likely that, after the pipeline is completed, welding slag will enter the instruments and damage their measuring components. It’s not worth it… As for grounding, connecting the case to ground is sufficient through the flange bolts; I generally don’t use compression bonding for grounding……
First, our shielding wires are all suspended in the field on the DCS side. The casing was not connected to the ground on-site, and it was also unknown that the welder could damage the instruments.