Site Acceptance of RTV Coating Quality

The acceptance of the in-site application quality of RTV coating is an important part of evaluating the overall application quality of RTV coating. The in-site acceptance method mainly includes the following aspects.

1. RTV coating appearance inspection

(1) For visual inspection, the upper and lower surfaces should be applied evenly, and the background color of the original insulator surface should be completely covered.

(2) The coating surface should be smooth and tidy, and there should be no accumulation, flow, bubbles, wire drawing, defects, or missing spraying.

(3) The coating should adhere well to the insulator surface, and there should be no peeling phenomenon.

2. The applied thickness should meet the technical requirements. After the RTV coating is fully cured, the thickness should meet 0.4~0.5 mm.

The applied thickness measurement method is as follows:

RTV coating sample should be randomly selected on the upper and lower surfaces of the insulator, but the sampling location does not include the edges and corners of the insulator. Use a paper cutter or other suitable tools to cut the coating sample. After sampling, the sampled part should completely expose the enamel or glass surface of the insulator. The size of the coating sample is about 10 mm×10 mm. The surface of the cut sample should be free of defects such as protrusions, pits, and bubbles. The contaminants on the surface of the sample should be removed before measurement. To measure the thickness of the coating sample, the measurement accuracy of the tester should not be less than 0.01 mm.

3. Selection of acceptance test point for RTV coating

(1) Visual inspection: All application equipments should undergo visual inspection.

(2) Test requirements for applied thickness:

Samples should be taken from each tension tower.

Random inspection can be adopted for tangent tower sampling. The sampling ratio of tangent tower must be more than 30%, and the sampling interval shall not be more than 5 bases.