PROCEDURE FOR APPLICATION OF PROTECTIVE ENAMEL ON INTERNAL SURFACE OF PIPE AND PROCEDURE FOR COATING QUALITY CONTROL Russian patent published in 2011 - IPC F16L58/02 C23D5/02 

FIELD: machine building.

SUBSTANCE: procedure for application of protective enamel on internal surface of pipe consists in preliminary surface cleaning, in application of enamel and in drying. Also, initially pipe is heated and dried by blowing air of t=+40÷80°C through it. Further, internal surface of the pipe is cleaned by an abrasive-jet method for elimination of impurities and obtaining roughness as high, as R_Z 40, where upon dust is removed by air blowing. There are applied not less, than two layers of enamel. Each wet layer of enamel has thickness, as high as 90÷180 mcm. Each enamel layer is dried at flow rate 2÷8 m/sec by blowing air of temperature +15÷25°C through pipe during not less, than 3 hours. Interval between application of layers should last no more, than 24 hours. Here is also disclosed the procedure for control over application of a protective cover on internal surface of the pipe. A sample in form of a cylinder of length equal to 0.5-1.5 diametre of a pipe is cut out from the pipe with protective enamel applied on it as a coating. The sample is subjected to compression in a radial direction till coating fractures. Quality of protective coating is determined by a value of deformation of the sample at the moment of detection of this coating fracture.

EFFECT: simplified process, raised efficiency, reduced power input and upgraded quality of coating.

2 cl