A double-sided electric fusion pipe fitting for composite pipe and its connection method

Abstract

The invention relates to a double-faced electric smelting pipe fitting composed of a metal reinforced material layer serving as the middle and thermoplastic plastic composite layers serving as inner and outer layers and used for steel-plastic composite pressure pipeline and a connecting method. When a composite pipe interlayer is made of metal, the electric smelting pipe fitting in a casing pipe is firstly arranged on the outer surface of the composite pipe end in a sleeving mode, then the electric smelting pipe fitting outside the casing pipe is sleeved with a gasket and is inserted into a composite pipe hole, the step end face of the electric smelting pipe fitting outside the casing pipe is fit with the step end face of the electric smelting pipe fitting in the casing pipe, the composite pipe and a pipe network are fixed, an electric smelting welder is turned on, the electric smelting pipe fitting in the casing pipe and the outer surface of the composite pipe are molten integrally, whether an outward protruding state and size of a welding measurement core meet the requirements or not are detected through the welding measurement core, then the electric smelting pipe fitting outside the casing pipe is turned on and is molten with the inner surface of the composite pipe and the electric smelting pipe fitting in the casing pipe, and finally whether the outward protruding state and size of the welding measurement core meet the design requirements or not are detected through the welding measurement core.

Description

technical field [0001] The invention relates to a steel-plastic composite pressure pipeline with a metal or non-metal reinforcing material layer in the middle and a thermoplastic composite layer on the inner and outer layers, and a double-sided electrofusion pipe fitting for a steel-plastic composite pressure pipeline and a connecting method, which belongs to the connecting pipe fitting for a composite pressure pipeline manufacturing field. Background technique [0002] In the existing patent publications, there are many publications about the installation pipe fittings and connection methods of multi-layer composite pressure pipes. Pipe end flaring, flange fastening connection; double-sided hot-melt pipe fittings, use electric heating tools to heat the inner and outer plastic of the composite pipe and the installation joint surface of the pipe fittings at the same time, and then quickly insert the pipe into the pipe fittings for hot-melt connection ;Electromagnetic welding...

AI Technical Summary

Problems solved by technology

[0003] There are some deficiencies in the above-mentioned installation pipe fittings and connection methods of the composite pipe. The mechanical fastening connection and the flange fastening connection pipe fittings all use plastics that strongly compress the pipe port (the flange type uses flared mouth) and use rubber sealing rings. The disadvantage of the sealing method is that the rubber sealing ring is easy to age, and the plastic on the joint surface is continuously deformed and loose, which affects the sealing performance; the double-sided hot-melt pipe fittings are connected by thermal fusion of the inner and outer layers of the composite pipe and the plastic on the joint surface of the pipe fittings. The connection strength and sealing performance Better, but, using electric heating tools to heat the joint surfaces of pipes and pipe fittings at the same time and then insert them into welding, there is a problem that the pipes and pipe fittings must be heated to the molten state of plastic at the same time, the heating requirements are high, and there are many influencing factors. The inner and outer molten layer plastics may be peeled off, resulting in pipe blockage or insufficient welding strength, making installation and connection operations difficult

The installation method of electromagnetic induction welding is to insert the pipe into the socket of the pipe fitting first, and then heat it with a special electromagnetic induction heating tool to make the middle steel pipe layer heat, which is transmitted to the plastic layer and the joint surface of the pipe fitting, so that the joint surface of the pipe and pipe fitting is fused Integral; its shortcoming is that it requires high matching precision of pipes and pipe fittings, the size of plastic extrusion and injection molding processing is difficult to achieve or the dimensional accuracy is unstable, which affects installation and matching. The temperature of the steel pipe is too high, and the local secondary heating of the composite pipe may affect the composite bonding strength of the steel pipe and the plastic, especially when the installation fit gap is too large and the heating time is long, the connection strength between the pipe and the fittings may be affected. greater impact

Images