Vessels or hollow structures which incorporate enclosed sections must have provision for adequate venting during galvanizing. At galvanizing temperatures any moisture present in closed sections is rapidly converted to superheated steam, generating explosive forces unless adequately vented to the atmosphere.

For the safety of galvanizing personnel, equipment and the work being galvanized, it is essential that venting is provided.

Correct venting ensures that the entire internal surface of work is properly galvanized and fully protected. This also ensures that lighter items will not float in the zinc bath due to trapped air pockets Closed vessels which are not to be galvanized inside, such as certain types of heat exchanger, must be provided with snorkel-type vent pipes long enough to project above the level of pickling, fluxing and galvanizing baths when the work is fully immersed. The exact venting requirement should be discussed with the galvanizer.