Flange static electricity issue
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During the on-site inspection yesterday, the experienced technician pointed to the anti-static bonding wire on the flange of a compressed air pipeline and asked me whether this anti-static bonding wire was necessary I was completely confused in an instant – the connection was already established, so why wasn’t it needed? The experienced worker said: It’s not needed here. Do you know why? What I’m wondering is: is it because there’s air inside the tube? The experienced worker said: This flange has 8 bolts, and no more than 4 of them need to be used. Huh? Is this statement still around? Dear sea friends, please discuss actively which standard contains such a statement Also, are there any other situations where it is not necessary to install anti-static bonding wires?
More than 4 bolts are not needed; why? Same question!
Code for Design of Static Grounding in Petrochemical Industries SH3097－2000 4.3.3 When metal flanges are fastened using metal bolts or clamps, it is generally not necessary to install additional static connection wires; however, it is essential to ensure that there is good electrical contact between at least two of the bolts or clamps. Code for Lightning Protection of Petroleum and Petroleum Facilities GB 15599-2009 4.7 Pipelines 4.7.1 Oil transmission pipelines can be used as their own lightning arresters; the transition resistance at joints such as elbows, valves, and metal flanges must be greater than 0.03 ohms. Metal wires should be used to bridge these joints, and terminal connectors should be pressed into place at those joints. For metal flanges connected by no fewer than 5 bolts, in a non-corrosive environment, it is not necessary to make a bypass connection, but an electrical path must still be established.
There is no need for static bonding when more than four bolts are used, or when metal gaskets are employed
Nonsense; bolts do not serve any purpose in dissipating static electricity. For applications where fire and explosion risks exist and static electricity needs to be prevented, copper wires are used to connect the two flanges together.
Flanges with 8 bolts do not require an electrostatic bypass wire, as the resistance is already low enough
No bridging is required for more than 4 bolts
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