DEVELOPMENT TRENCHLESS TECHNOLOGY ECONSTRUCTION OF PIPELINE COMMUNICATIONS WITH A CLEANING PISTON

Abstract

The expediency of reconstruction of pipelines of Ukrainian cities with trenchless technologies is substantiated. The technology of trenchless reconstruction by extending a smaller diameter polyethylene pipe into a worn steel pipe is described – the method of "pipe in a pipe". The advantages of this method are presented. The analysis of possibilities of existing traction means for carrying out of such works is carried out. The technology of trenchless reconstruction of pipeline communications by developing a new polyethylene pipeline into a worn steel cleaning pig has been developed. A section of a new polyethylene pipeline is attached to the cleaning pig by a barbell. The pig moves under the pressure of air, which is fed into the cavity space by the compressor. The inter-tubular space in the working trench is sealed with a sealing system, which is clamped by a clamp or flange to a worn steel pipeline.
 The mathematical modeling of the process by pipeline drainage with a cleaning pig is executed. Dependences were obtained for the calculation of the resistance forces acting on the moving system, namely, the mechanical friction forces of the pig cuff to the walls of the steel pipe, the friction forces of the polyethylene pipe to the steel, the friction force of the polyethylene pipe in the cuffs of the sealing system. Dependences are obtained which allow us to calculate the required pressure in the cavity space so that the pig has dragged a new polyethylene pipeline all along the length of the reconstructed horizontal or sloping worn steel pipeline. Under the design pressure in the cavernous space, equipment is selected to perform work