Pipeline static electricity bonding
Thread Content
For such DN80 pipes, the flanges are connected using 8 sets of M16 studs. The fire hazard level of the medium inside the pipes is Class B. Is the static grounding shown in the diagram really effective? Can’t 8 sets of M16 bolts connected together replace such an electrostatic bridge? Personally, I think the tightening force of those 8 sets of bolts should be better than that of a single stainless steel strap. The factory adopts this approach as part of its safety improvements; I’m not sure where such a standard comes from, and I hope colleagues can provide some guidance.
Static bonding is primarily intended to ensure the overall electrical continuity of the piping system, thereby preventing static electricity buildup from causing sparks that could lead to fires or explosions. Even though multiple sets of bolts can provide a good mechanical connection, they do not guarantee consistent electrical conductivity under all environmental conditions (such as grease, corrosion, vibration, etc.). Using specialized static bonding straps can provide additional safety guarantees. Whether static grounding is required should be determined based on the relevant safety standards and actual operating conditions. Safety improvements are typically designed with preventive measures based on the worst-case scenario to ensure safety over the long term and under various operating conditions. .
Flanges with more than five studs no longer require bridging, unless specified by the design.
The most common issues in the pictures you showed are likely inadequate equipment maintenance leading to severe rusting, excessive residual weld height visible during inspection of the flanges, and improper installation of studs
From the video, it can be seen that the jump wires are not used properly; what’s required is to use (special woven copper jump wires available on the market), and attach the wire terminals to the bolt washers in a manner similar to bolts, then tighten them. The resistance of such a link will continue to increase as the metal oxidizes, failing to provide any safety protection. Using bundling to connect circuits is really unreliable; it indeed needs to be improved. Additionally, the double-headed bolt installation on the flange is terrible – one side of the screw is too large while the other side is not large enough. Moreover, the flange is severely corroded; it should be made of stainless steel to match what is shown in this diagram. For reference.
It’s just an electrostatic bridge; it has nothing to do with the tightening force
Firstly, the flange on the right side is made of carbon steel, while the pipe is made of stainless steel; this involves welding of different types of steel, and the welds are not regular, which indicates quality issues in the construction process. Secondly, regarding static electricity bonding, according to the standards, it is not necessary to carry out such bonding based on the flange diameter or the number of connection bolts, as the cross-sectional area of these bolts meets the requirements for static electricity dissipation. Thirdly, if bonding is to be carried out, the connection between the bonding wires and the flange must meet certain requirements – welding should be used instead of using metal straps for fastening. Lastly, the contact surfaces between the two small bolts used for bonding and the flange need to be protected against rust and oil; clearly, this does not meet the required standards
The workmanship is a bit rough. It’s a bit complicated.
It’s not necessary to cross them; the regulations specify that having more than 5 bolts is sufficient to meet the requirements. Or it is possible to omit the bridge when the resistance value is less than 0.03 ohms
If the resistance measured is less than 0.03 ohms, it is not necessary to use a bridge
Even if an electrostatic bypass is required, such a bypass is not proper