What type of bonding is specifically required for metal gas lines?

The requirement for electrical bonding of metal gas lines is grounded in safety and compliance with regulatory standards. Electrical bonding involves the connection of conductive objects to ensure that they are at the same electrical potential. This is crucial in metal gas lines, as it helps to mitigate the risks associated with electrostatic discharge or electrical faults, which could potentially ignite a gas leak.

In many codes, such as the National Electrical Code (NEC), bonding is mandated to prevent hazardous situations resulting from stray current or lightning strikes, which can lead to explosions or fires if combustible gases are present. Proper bonding ensures that any electrical fault will safely direct current away from the gas line, reducing the chance of ignition in the presence of flammable gases.

The other types of bonding mentioned do not apply in the context of gas lines. Molecular bonding pertains to the interaction between atoms and molecules and is not relevant to the physical safety or electrical concerns of gas lines. Thermal bonding is related to temperature management and is typically not a factor in the integrity of gas lines. Structural bonding involves the physical adherence of components in construction or manufacturing contexts, which is unrelated to the purpose of bonding in electrical safety.