Permanent connections designed to connect polyethylene pipes reinforced with synthetic yarns to steel pipelines (hereinafter referred to as the permanent connection) are fabricated by assembling of a piece of reinforced polyethylene pipe on a steel nipple of the insert by mandreling the central hole of the nipple.


The permanent connections are designed to weld TU 2248-001-55038886-01 reinforced pipes to steel pipelines of cold-water supply systems, process and petroleum pipeline systems of up to 4 MPa  working pressure, gas distribution networks of up to 1.2 MPa working pressure.

Неразъемное соединение

The permanent connections are designed to be applied at temperatures of pipeline walls ranging from +60C to -15C.

The permanent connections are butt welded to reinforced polyethylene pipes with the use of a heated device and then the weld is reinforced by an electrofusion sleeve in conformity with process documentation approved according to the established procedure.

The permanent connections are welded to steel pipelines in conformity with GOST 16037.

The temperature of a steel pipe in the area where it is connected to a reinforced polyethylene pipe is not to exceed 800C above zero. It is recommended that a permanent connection first be welded to a piece of steel pipe of 1 m long in the workshop environment where thermal conditions at the reduction sleeve area can be assured. In the process of adjusting steel pipes prepared for butt welding and subsequent reinforcement by an electrofusion sleeve, the operations of gas cutting and polishing of the edge should be performed at the steel pipeline end, not at the steel connecting piece end of the permanent connection. The polyethylene connecting piece should be protected from metal splash and dross in the process of joint adjustment and assembling, tick welding, and subsequent electric arc welding.

Steel inserts of permanent connections of oilfield pipelines shall be protected against external corrosion in compliance with PB (ПБ) 08-624 requirements.

In case of underground laying, gas pipelines are to be protected against galvanic attack by means of protective insulating heavy-duty covers in compliance with PB (ПБ) 12-529 requirements.

At crooked elastic parts of pipeline routes, assembling of connections is not permitted.

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