Method and system for coating internal surfaces of prefabricated process piping in the field

Procedure for coating the interior surfaces of a workpiece driving, this method comprising the following steps: - Set anodes (22, 24) through the openings of said workpiece driving (10) while maintaining time electrical isolation of said anodes with respect to said workpiece; said openings comprise at least one inlet and at least one output; - Connect a biasing system (20, 47) so that the said workpiece driving (10) can function as a cathode; - Attaching a vacuum source (30, 32) to each of said outputs of said workpiece (10); - Connect a gas source (12) to each of said inputs of said workpiece (10) for introducing a gas comprising a coating material.