METHOD OF PROTECTIVE COATINGS APPLICATION TO METAL PIPES AND UNIT FOR ITS IMPLEMENTATION

The known method of protective coating application to metal pipes includes dressing of the pipe surface, coating application and cooling. The offered technology differs from the traditional one in that first of all the pipe external surface is dressed by electric-arc discharges at atmospheric pressure in an atmosphere of shielding, reducing or shielding and reducing gas, then it is dressed by mechanical methods and after this - by arc discharges in vacuum in the rising section of volt-ampere characteristic with the use of a graphite as an anode, and the protective coating is applied to the pipe external surface in vacuum or at the outlet from vacuum and is accompanied by subsequent cooling with liquid coolant.

The patent describes the installation for coating application to metal pipes. In addition to such ordinary components as vacuum chamber with a hawse system, vacuumization equipment and unit for mechanical cleaning of the pipe external surface containing cartridges with metal needle-type elements, the installation is provided with a cooling system, unit for arc dressing at atmospheric pressure with arc modules and the system for supplying shielding, reducing or shielding and reducing gas. The vacuum chamber is equipped with arc modules, and the pipe external surface mechanical dressing unit is arranged in the direction of process run between the unit for arc dressing at atmospheric pressure and vacuum chamber, downstream of which protective coating application unit and liquid coolant cooling system are installed in series.

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