Lack – much greater complexity and fragility of the installation of pipelines. Cast iron pipes are made of gray iron castings in a stationary sand molds, as well as centrifugal and semi-continuous casting. The strength of cast iron pipes depends on the thickness of their walls, as well as the method of casting. Pipes manufactured by centrifugal casting and semi-continuous, stronger pipes made by casting in sand molds. To prevent corrosion of iron pipes from their outside and inside covers petroleum bitumen.
As a result, the inner surface of the pipe becomes more smooth, which reduces the friction of water against the pipe wall. Cast iron pipes are divided into pressure (water) and sewer. Water pipes made of nonferrous metals. Copper tubes are round, made of copper marks M1, M2 and M3. Copper Pipe Pulled produce cold rolled and outer diameters of 3 to 360 mm, wall thickness from 0.5 to 10 mm, Pressed – diameter from 30 to 280 mm, wall thickness from 5 to 30 mm. The outer and inner surface of the copper pipe must be free of cracks, cavities, bundles of metal. On the outer surface shall longitudinal risk, small dents, discoloration, the curvature of 5 mm to 1 m for the elongated tube and 15 mm at 1 m for extruded.
Drawn, cold-hard and semi-tube after annealing should try to flattening in the cold state (three pipe from the party). Brass pipes are made of brass brands: L63 and L68 – and cold-drawn tubes and L60, LS59-1 – extruded. Drawn and cold-rolled tubes for special purposes, intended for heat exchangers apparatus, made of brass brands LO70-1, LA77-2 LM68-0, 06. Brass and cold drawn tubes for general purpose release outside diameter of 3 mm to 10 mm, wall thickness from 0.5 to 10 mm, and pressed – with outside diameters from 21 to 195 mm, wall thickness of 1.5 to 42 mm. Along the length of such pipes are dimensional and random length from 1 to 6m. Drawn and cold rolled brass tubes produce a maximum length of 10 m and outer diameter of 10 mm and wall thickness of 1.5 mm. Quality requirements for outer and inner surfaces of pipes and brass to their curvature, the same as that for copper pipes. Pipes made of aluminum and aluminum alloys are produced by cold rolling (rolled) and cold-pulling (pull) and compression. Pipes of aluminum and aluminum alloys produced round, rectangular, square and oval. In recent years become widely drawn and rolled to get the tube shaped profile. The curvature of the pipe wall thickness up to 5 mm inclusive in diameter and 120 mm should not exceed 1 m in length, 1 … 3 mm. On the surface of the pipes allowed longitudinal risks of not more than two 10 mm perimeter depth of not more than 0.04 mm. The pipe ends must be cut evenly and not be free of burrs. Polymer (plastic) pipes of water supply. Plastic pipes are distinguished strength and elasticity, high corrosion resistance, light weight, low thermal conductivity, smooth inner surface. Hydraulic resistance of fluids in plastic pipes less than metal, so their capacity is 20-25% higher. In addition, due to the production of long plastic pipes is reduced number of joints in the pipes. Shaped fittings made of plastic, used for assembly lines, ensure their quick and safe assembly. Negative properties of plastics pipes – low heat resistance, sensitivity to mechanical damage, the propensity to aging and others Ltd. "FOR-Vent"