METHOD OF NON-DETACHABLE CONNECTION OF POLYMERIC REINFORCED PIPES Russian patent published in 2004 - IPC

FIELD: pipeline transportation of gaseous and liquid mediums under pressure. SUBSTANCE: the invention presents a method of a non-detachable connection of polymeric reinforced pipes. The method may be used in the pipeline transportation of gaseous and liquid mediums under pressure in different industries, in municipal and agricultural economy. The method provides for sliding a connecting union over one of pipes, heating butts of pipes, pressing them to each other, a butt-seam welding of pipes, moving the union over the weld seam, heating the union, applying a radial loading onto it, aging and cooling. At that in the capacity of the connection union a polymeric thermocontractable union is being moved forward sliding over one end of one of the pipes. A ring made out of a corrosion-resistant steel is set on a tip of one of the pipes by a half of its length. A highly heat-conducting bush is inserted in the ring. Between the bush and the but of the second pipe they install a heating plate and press the pipes to each other. After heating the butts up to the temperature close to the polymer melting point, the heating plate and the highly heat-conducting bush are removed. Then after the butt-seam welding of pipes is over and the butt-seam of the pipes is cooled a press-heater is set on the ring and the power supply of the heating elements is switched on. After the joint reaches the temperature close to the melting point of the polymer, the ring is being squeezed by the press-heater forming in it the ring type and longitudinal ridges, and on the tips of the pipes meeting them ring-type and longitudinal grooves. Then the electric heating is switched off, the joint is cooled, the press-heater is removed, the thermocontractable union is heated up till the given temperature and they move it forward to slide it over the ring. Then the joint is exposed to the natural cooling. The invention allows to increase the tensile strength and twisting strength of the non-detachable coupling of the pipes. EFFECT: increased the tensile strength and twisting strength of the non-detachable coupling of the pipes. 3 dwg