COVERING OF THE PIPELINE INNER SURFACE AND METHOD OF APPLYING THIS COVERING ON THE PIPELINE INNER SURFACE Russian patent published in 1995 - IPC

FIELD: building. SUBSTANCE: covering of the pipeline inner surface represents a three-layer structure containing two coaxially located tubular shells made of the polyethylene-containing film. The outer shell is adjacent to the inner side of the pipeline, the inner shell is separated from it by the coaxial reinforcing layer impregnated by the binder. In this covering at least the inner shell made of the polyethylene-containing film is rigidly connected with the reinforcing layer by transverse chemical connections. For this purpose the polyethylene-containing film of the inner shell contains the joining agent capable of forming the transverse chemical connections. The method of applying this covering on the pipeline inner surface lies in the fact that tubular shells made of the polyethylene film are coaxially placed exterior to the pipeline. One of the shells is designed for adjoining the pipeline inner surface. The inner shell has the joining agent. The coaxial reinforcing layer is placed between the shells. It is impregnated with the binder. Thus the three-layer structure of the covering is obtained. This structure is inserted to the pipeline. After that the hermetic sealing of the inner shell cavity and the thermal treatment of the three-layer structure are carried out at the temperature of 85-120 C and at the pressure of 0.005-0.075 NPa for the period enough to form the transverse chemical connections between the inner shell and the reinforcing layer. EFFECT: enhanced quality of covering, enhanced service life, reduced power consumption. 23 cl, 4 dwg