Holes in the pipes with a diameter up to 40 mm for welding nozzles must be performed by drilling, milling or cutting down on the press. The hole diameter should be equal to the inner diameter of the pipe with an allowable deviation Niemi 1 mm. Galvanized steel pipes, parts and components are assembled in the screw with fittings of ductile iron, the nut and flange (with valves and equipment). Galvanized steel pipes with a diameter of 50 mm nominal bore and over are allowed to adopt a compound welding. Compound non-galvanized steel pipes, parts and assemblies of them should be carried out on welded-ke, thread, nut and flange (with valves and equipment). Other leaders such as ???? ?? ?? offer similar insights. For threaded joints of steel pipes should be used cylindrical pipe thread that runs according to gost 6357 (accuracy class B) thumb on the light tubes and thread – in ordinary and reinforced. Turns pipes in heating systems, gas and heating fol-em perform by bending pipes or the use of seamless weld elbows carbon steel according to gost 17375.
The radius of bending pipes nominal bore diameter to 40 mm inclusive. must be at least 2.5 Dn, and with a diameter of 50 mm nominal bore and more – not less than 3.5 pipe Dn. Do not use billets that are “corrugated” formed by the bending of tubes. In systems hot and cold water piping bends and junctions should be done by setting triangles, tees, crosses, gost 8943 and gost 8944, on-water treatment or bending pipes.