Device and method for connecting and sealing steel-plastic composite steel pipe, flange metal pipe and pipe fitting

Abstract

The invention provides a method for connecting and sealing a steel-plastic composite steel pipe, a flange metal pipe and a pipe fitting, and further provides a device for connecting and sealing the steel-plastic composite steel pipe, the flange metal pipe and the pipe fitting. The method comprises that at least one rabbet is formed on the periphery of the outer end surfaces of flange gaskets of the steel-plastic composite steel pipe; hot melt adhesive is coated on the outer layer of an inner liner plastic pipe layer of the steel-plastic composite steel pipe; the steel-plastic composite steel pipe with the hot melt adhesive coated on the outer layer of the steel-plastic composite steel pipe is embedded in an outer layer pipeline, and the inner liner plastic pipe layer is extended and coated on the end surface of the outer layer pipeline; and a silica gel gasket is arranged between end surfaces of two flange gaskets. The device for connecting and sealing the steel-plastic composite steel pipe, the flange metal pipe and the pipe fitting is simple in sealing and connecting method, reliable, stable and strong in sealing ability, and has prominent and active effects for engineering applications in the fields such as subways, industrial architecture and drinking water.

Description

technical field [0001] The invention relates to a connection and sealing device and method for steel-plastic composite steel pipes, flanged metal pipes and pipe fittings, in particular to a plastic-lined steel pipe sealing connection device for steel-plastic composite steel pipes. Background technique [0002] Steel-plastic composite steel pipes are widely used in public buildings, water supply and drainage, petroleum, chemical industry, mining and other fields. During use, steel-plastic composite steel pipes must ensure that no liquid or gas in the pipe leaks. The key technical difficulty lies in the sealing of the pipe joints. During the use of steel-plastic composite steel pipes, the pressure of high-pressure water is 3-4kg, while the industry standard requires only 0.3kg of shear strength for steel-plastic composite steel pipes. Therefore, steel-plastic composite steel pipes designed according to industry standards During use, if the sealing device is not designed, the i...

AI Technical Summary

Problems solved by technology

The invention patent with the application number 03117217.2 discloses a small flange connection pipe fitting for high-pressure stainless steel pipes. It has a groove on one end of the flange and inserts a sealing ring, but there is only one sealing ring, which is not safe and reliable. The second embodiment of the invention A sealing method using an internally expanding sealing sleeve is disclosed, but the sealing sleeve may be dislocated due to the pressure difference above the two pipes, resulting in defects such as sealing sleeve rupture and sealing failure

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