Hot shrinkage/melt bush and manufacturing method and construction method thereof

Abstract

A hot shrinkage / melt bush and a manufacturing method and a construction method thereof are disclosed. The invention relates to a pipe joint technique. The invention solves the problems that the current radiation crosslinking hot shrinkage bush is not hot-melting on the inner wall thereof, the electric hot melt bush is free from hot shrinkability, and the hot melt bush after the heat sealing has longitudinal seams; the invention provides a hot shrinkage / melt bush and a manufacturing method and a construction method thereof. The inventive hot shrinkage / melt bush is a plastic pipe, average gel fraction of the outer layer of a pipe wall is 50%-70% and the gel fraction of the inner layer of the pipe wall is less than 0.6%. The manufacturing method thereof comprises the steps of irradiating theplastic pipe by an electronic beam in a non-penetrable manner so that the outer layer of the pipe wall of the plastic pipe is highly crosslinked and the inner layer of the pipe wall of the plastic pipe is lowly crosslinked, and then heating, expanding and shaping the pipe. The usage method thereof comprises the steps of helically coiling an electric hot wire screen outside a polyethylene pipe; then heating to shrink the hot shrinkage / melt bush outside the electric hot wire screen, and in the end, heating the electric hot wire screen to heat-seal the inner wall of the hot shrinkage / melt bush with the polyethylene pipe under the electric hot wire screen.

Description

technical field [0001] The invention relates to a pipe joint technology used for joints of thermal insulation pipes and petroleum pipelines, in particular to a heat-shrinkable heat-melt sleeve and its manufacturing method and construction method. Background technique [0002] Since 1980, more and more integral prefabricated direct-buried anti-corrosion insulation pipe systems have been used in the domestic oil transmission pipeline network and underground hot water pipeline network. It is an insulation pipe fitting composed of a working steel pipe, a polyurethane insulation layer and a polyethylene shell pipe. When the insulation pipe fittings are connected on site, the insulation joints are generally sealed with radiation cross-linked heat shrinkable sleeves or electric heating sleeves. Since radiation cross-linked materials and uncross-linked plastic materials are difficult to fuse directly, radiation cross-linked heat shrinkable sleeves The inner wall is mostly coated wit...

AI Technical Summary

Problems solved by technology

[0003] In order to solve the problems in the prior art that the inner wall of the radiation-crosslinked heat-shrinkable sleeve does not have heat-fusibility, the electric-heat-fused sleeve does not have heat-shrinkage and the welded heat-fused sleeve has longitudinal seams, it provides a Heat-shrinkable heat-melt sleeve and its manufacturing method and construction method

Images