TUBING WITH AN INNER COATING PROTECTING IT AGAINST DEPOSITS AND A METHOD FOR APPLYING SAID COATING

摘要

A method for applying a coating to a tubing is provided, wherein the tubing includes inner walls and end faces. A plug, having outer walls, is inserted into the tubing, so that the longitudinal axes of the plug and tubing coincide and internal space is provided between the inner and the outer walls. The inner walls are preferably heated up. Polyurethane is pumped into the internal space until it's filled up. Polyurethane is held to the full cure thereof. The plug is then extracted from the tubing, thereby producing the coating. The outer walls are preferably lubricated. Optionally, a reinforcement tube is inserted into the tubing. The tube is configured as a web made of perforated metal, and has a diameter equal to the inner diameter of tubing. Two mandrels are provided, so configured that can centering the plug during the insertion, and are fitted onto the end faces.