APPLICATION OF ENAMEL COAT ONTO PIPE INNER SURFACE Russian patent published in 2013 - IPC B05D7/22 

FIELD: process engineering.

SUBSTANCE: invention relates to machine building, particularly, to application of protective coats on tube inner surface and to methods of quality control to be applied to said coats. Proposed method comprises surface pre-cleaning, enamel application and drying. First, pipe is heated and dried by blowing air there through at t=20-80°C. Then, pipe inner surface is subjected to sand blasting to eliminate dirt and to ensure roughness, at least, R_Z35. Dust is removed by air blowing. Now, at least, two layers of enamel are applied. Note here that every enamel wet layer thickness makes 90-180 mcm. Enamel layers are dried by blowing air through the pipe at the rate of 2-8 m/s for, at least, 3 hours, air temperature making 20-25°C. Interval between application of layers should make, at least, 24 hours.

EFFECT: simplified and higher quality of coats.