According to All-union State Standard 50838-95 pipes for gas conduit can be manufactured from ПЭ-80 and ПЭ-100 low pressure polyethylene. They serve for construction of underground gas lines transporting natural heating gas which is used in domestic and industrial fields as a fuel.

The pipes are from 20 to 315 mm in diameter and have a standard dimensional ratio SDR (of a nominal outer diameter to a nominal side thickness) of 9, 11, 13.6, 17, and 17.6.

Working pressure of the pipes produced is from 3 to 12 atm.

Black is a standard colour. The pipes are produced with longitude yellow stripes drawn steadily on a pipe section circle. These stripes are made by coextrusive method. Their width is up to 4 mm.

The pipes have also a marking of meterage, a manufacturer/supplier name, parameters, material, production date and an identification mark.

The pipes are joined by welding or with connections.

Technical and economic advantages in comparison with steel pipes:

• low gas permeability;
• possibility of laying in corrosive medium and service life of more than 50 years due to high corrosion resistance to the environment and transported gas;
• high impact resistance even at a low temperature (temperature service interval is from 20o below zero to 30o above zero (C);
• ease and reliability of joining;
• due to flexibility few fabricated shapes are used;
• no need for corrosion preventive work due to low stagnation of corrosive deposit;
• high flow capacity owing to smooth internal surface;
• low hydraulic impact susceptibility and safety at water freezing due to elasticity;
• minimal condensate and best sanitary conditions inside buildings due to low heat conductivity;
• thanks to their light weight the pipes are easy to keep, store, transport and assemble;
• excellent ratio of price and quality in comparison with other types of pipes;

Usually trench method is used for pipelining of polyethylene pipes but there are also some innovation techniques, for example, guided underground drilling or pulling of a new plastic pipe inside an old metal one. Due to these two methods there is no need to open the ground and dismantle old lines or do other actions resulting in big costs.

Transportation, Warehousing and Storage

Polyethylene pipes for gas conduit can be kept in the open air at a temperature from 50o below zero to 60o above zero C. It is recommended to keep the pipes for 6 months maximum to save a pipe colour and a marking.