At present, major repair and reconstruction of building engineering systems by replacing cast iron sewer and water and gas steel pipes for pressure and pressure polyethylene and polypropylene. Each year, the share of Russian market of the material increases, and for 2009 it is about 69%. The use of polymer materials for installation of engineering systems is optimal in terms high content of dissolved salts in the water and alkali metals. Polyethylene and polypropylene have a low heat loss, which can significantly save money, this savings is more evident when presence in the building-mounted heat points (ITP). The use of pipelines made of polyethylene and polypropylene simplifies installation and increases the reliability of tube connections. Life data pipes is 25-50 years.
Overview of polyethylene and polypropylene, polyethylene – the material in white, solid thermoplastic. It has high chemical resistance. Polyethylene obtained by polarization Ethylene evolved from pre-mixes produced during processing of petroleum or natural gas. Polypropylene obtained by polymerizing propylene in the presence of metal catalysts. Polyethylene manufactured by two methods: high pressure (up to 1500 kg/cm2) and temperatures up to 180 C when exposed to oxygen at low pressure (5 – 40 kg/cm2) and a temperature of 60 – 150 C with the use of special catalysts. Polyethylene obtained by the first method, called low density polyethylene (PNP), obtained by the second method – high density polyethylene (HDPE). Polyethylene less durable than high-density polyethylene. Pipes from the tng is used in temperature not exceeding 60 – 70 C, and from the eta – not more than 80 -90 C.