Abstract: 3LPE coating, consisted of epoxy powder, copolymeter adhesive and polyethylene, has a perfect performance in corrosion control and cathodic disbonding resistance. To ensure plant-applied quality of 3LPE coating, each operating sequence, including monitoring and inspection and E & ST on raw materials, must be controlled in accordance with relative standards or codes. The matchability between materials should be tested to determine coating parameters. Meanwhile, test on steel pipe and coating have to carry out and every measurement must be in accordance with the technical requirements.