1. Quality detected by sampling way depending on design requirements.

2. Visual inspection by the root. Covering the surface layer should be uniform, smooth, no bubbles, wrinkles, protruding tumor and uneven hem overlay defects.

3. Film thickness with magnetic gauge, measuring 1.5 meters in every single section of pipe ends and the middle point of the circumference, the film thickness should meet two 85%: the 85% of the thickness of the measuring point design requirements, less than the thickness of the measuring point, with the minimum should not be less than 85% of the design thickness.

4. Check the pinhole pinhole tester, found pinholes, sanding with sandpaper grinding machine painted up.

5. Insufficient film thickness or pinholes, after curing repair should be reviewed, the failure to repair again, until qualified.

6. Check adhesion, with a hard coating on the draw tool is cut at an angle of 60 to conduct random checks, shall be classified through direct coating substrates, taped designated port portion, tear tape hindsight scratches, coating should be no peeling. There may also be checked under the same conditions on the painting model.