Coating method for cast iron pipe fitting joint and the coated castiron pipe joint by polyethyene

Abstract

Disclosed is a pipe joint for connecting pipes in order to form a pipeline such as a water supply pipeline and a sewerage pipeline, and more particularly to a cast-iron pipe joint in which the inner and outer surfaces thereof are coated with a polyethylene resin. The present invention relates to a cast-iron pipe joint such as L bends, T branches, Y branches, an increaser connecting pipes of different diameters, for connecting pipes in order to form a pipeline. The inner and outer surfaces of the cast-iron pipe joint are coated with a polyethylene resin through a preprocessing process, a heating process, a coating process, and a cooling process. In the coating process, air is blown through a filtering net from the lower side of a coating tank containing polyethylene resin powder, in order to float the polyethylene resin powder. The heated cast-iron pipe joint is introduced into the coating tank, and is rotated so that the polyethylene resin is adhered to the pipe joint. Thereafter, the pipe joint is cooled in cooling water to contract the coating film and gloss the surfaces of the pipe joint.

Description

technical field [0001] The present invention relates to a pipe joint for connecting pipes to form pipes such as water supply pipes and sewage pipes, and more particularly, to a cast iron pipe joint coated with polyethylene resin and synthetic resin coated on the inner and outer surfaces of the cast iron pipe joint Methods. Background technique [0002] Generally, cast iron pipes are used for water supply and sewage. Pipes are connected using various shapes of couplings to form pipes. [0003] In other words, use L-bends where the pipe bends into an L shape, and T- and Y-branches where the pipe is T- and Y-shaped. In addition, reducing joints are used to join pipes of different diameters to form pipes. Forming piping in this manner requires a large number of unions and straight pipes. [0004] Traditional cast iron pipe and fittings are coated with coal tar by immersion in a coal tar bath, or coated with paint (epoxy paint) to prevent rust. [0005] Coal tar is the final...

AI Technical Summary

Problems solved by technology

Therefore, coal tar is not an ideal coating method

[0007] Also, since coal tar is an ultimate by-product of crude oil, it is harmful to humans

Also, because coal tar applied to cast iron pipes dissolves into water and people drink the tar, coal tar coatings are not suitable for water supply pipes

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