Method for fabricating plastic lining steel tee joint pipe fitting

Abstract

The invention discloses a method for fabricating a plastic lining steel tee joint pipe fitting and belongs to the technical field of composite steel tube design and manufacturing. The method for fabricating the plastic lining steel tee joint pipe fitting is applicable to various calibers and can guarantee the heat seal effect of plastic lining layers to the greatest extent. The fabrication method comprises the following steps of firstly, preparing a parent tube which constitutes a branch tube and a branch tube extension section; then welding the parent tube to a branch tube joint of a straight tube; subsequently, conducting integrated hot melting plastic lining on the straight tube and the parent tube, and meanwhile lining a composite layer transitional structure out of the tail end of a connection structure of the parent tube; then, installing the branch tube extension section where the plastic lining layer is completed to the tail end of the parent tube through the connection structure, and sealing the plastic lining layer at the inner side of the branch tube extension section and the plastic lining layer at the inner side of the parent tube through the composite layer transitional structure. By the mode, the plastic lining composition work for a plastic lining composite tee joint steel tube is completed.

Description

technical field [0001] The invention relates to a manufacturing method, in particular to a manufacturing method for plastic-lined steel tee pipe fittings, and belongs to the technical field of design and manufacture of composite pipe fittings. Background technique [0002] In the prior art, the inner plastic layer of the plastic-lined steel tee pipe fitting is made by injection molding or rotational molding. Structurally, since there is no effective bonding between the inner plastic layer and the inner wall of the steel pipe fitting, when there is negative pressure in the piping system, the inner plastic layer of the plastic-lined steel tee pipe fitting is easily absorbed. The inner anti-corrosion structure of plastic-lined steel tee pipe fittings is destroyed; and in terms of technology and processing equipment, due to the extremely complex structure of processing equipment and tooling molds, these processes are restricted in the use of large-diameter plastic-lined steel te...

AI Technical Summary

Problems solved by technology

Structurally, since there is no effective bonding between the inner plastic layer and the inner wall of the steel pipe fitting, when there is negative pressure in the piping system, the inner plastic layer of the plastic-lined steel tee pipe fitting is easily absorbed. The inner anti-corrosion structure of plastic-lined steel tee pipe fittings is destroyed; and in terms of technology and processing equipment, due to the extremely complex structure of processing equipment and tooling molds, these processes are restricted in the use of large-diameter plastic-lined steel tees. The use of tee pipe fittings makes the caliber of plastic-lined steel tee pipe fittings on the market mostly below DN150, which is difficult to meet the market's needs for large-diameter plastic-lined steel tee pipe fittings.

At the same time, the plastic-lined steel tee pipe fittings produced by these existing processes have not been effectively bonded between the inner plastic layer and the inner wall of the steel base pipe. When negative pressure occurs in the pipeline system, the plastic-lined steel tee The inner plastic layer of the pipe fittings is also easily sucked flat and deformed and peeled off, which destroys the inner anti-corrosion structure of the plastic-lined steel tee pipe fittings and hinders the reliable use of the plastic-lined steel tee pipe fittings

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