FIELD: construction engineering; repair of pipe lines without discontinuation of handling the product. SUBSTANCE: prior to mounting reinforcing coupling, pressure in pipe line is reduced to rated level. Then, mechanical force is applied at leaky area of pipe line by normal to external surface of envelope, polymer envelope is heated to polymer softening temperature, envelope is tightly pressed to pipe line over entire perimeter, after which polymer is cooled down and mechanical force is removed. Part of deformed envelope on either side of leaky area is removed over perimeter and reinforcing coupling is secured to pipe line, after which pressure is raised to working level. EFFECT: extended field of application. 4 dwg
