Pump compressor pipe, Dnipropetrovsk region.

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Pump-compressor pipes (tubes) serve to extract liquid andgas from wells, inject water, compressed air (gas) and perform various types of work on current and capital repair of wells. They are made in two types: with smooth ends and with protruding ends, on which an external thread is cut, and a connecting coupling is screwed onto one end. At a distance of 0.4 - 0.6 m from the end of the pipes, on the side of the couplings, a stamp - marking is punched out. It indicates: conventional pipe diameter, mm; steel strength group; wall thickness, mm; trademark; month and hour of issue. Smooth pipes and couplings to them are made of steel of strength groups K, E, L, M, and pipes with raised ends are made of steel of strength groups D, K, E, L, M. The surface of their thread is covered with grease that ensures the tightness of the connection and protects against burrs and corrosion.(//tractor-service.com)
Bezmuftovye pump-compressor pipes (NKB) ensure the tightness of connections at pressures up to 50 mPa. Their ends have a landing outwards; the connection has great strength. The tightness of the joints is ensured by conical sealing surfaces located behind the thread on the side of smaller diameters. A trapezoidal thread is used in the pipe connection.
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