Use of fiber-glass materials for protection of industrial pipes against corrosion

Abstract

A method to increase the resistance to spread of crack-like and corrosion defects on the outer surface of pipelines by using a new, developed, multicomponent composite coating and a method for its application has been developed. The method is effective in terms of applying repair coating without taking the pipeline out of service. The protective coating, obtained according to this method to protect pipes from damage, is marked by heat resistance, strength, high adhesion to steel pipes, high insulating and anti-corrosion properties. The viscosity at impact of the coating obtained is 15 J, which corresponds to a very reinforced coating of class B. To reduce water absorption and increase adhesion, a polyurethane coating is applied to the pipe, which has water-repellent properties. This makes it possible to exclude from the process of strengthening the pipeline an additional finishing operation (applying a hydrophobic water-repellent coating to the surface of the pipe). After applying fiberglass to the epoxy coating layer, fiberglass coating is obtained, which, due to its high wetting ability and adhesion of epoxy resins to fiberglass, has high static and dynamic strength. Due to the low shrinkage of epoxy resins during their curing, microcracks are not formed on the surface of the coating. When fiberglass comes into contact with a heated polyurethane coating, an elastic layer is formed, which ensures reliable adhesion of the coating to the pipe; the transient specific electrical resistance of the coating is 1.1 ∙ Ohm/m2. Thus, the resulting coating is compatible with the cathodic protection system and ensures the resistance of the coating to peeling during cathodic polarization, as well as high resistance of the coating adhesion to steel in wet conditions. The coating is intended for both underwater use and for dry conditions, as well as for long-term operation wet conditions at temperatures up to 65º C. In relatively dry conditions, the coating operating temperature is up to plus 100º C. The coating is designed to protect and strengthen the surface of steel oil and gas pipelines at the stage of their manufacture, construction, transportation and repair. This coating can be used in other industries to protect pipelines and tanks from atmospheric, soil and other types of corrosion, as well as from mechanical damage.