Gas supply pipes

The gas pipeline diameter is determined by the design gas flow and the network's working pressure. Pipe-Plast produces gas pipes in diameters from 20 to 1200 mm, covering medium- and high-pressure distribution and trunk gas lines. Gas supply uses the SDR11 class: it gives a thick wall and the safety margin required for transporting gas.

Unlike water supply, thin-walled classes are not used for gas — safety and pressure reserve matter more than throughput here. If you are unsure about the diameter and SDR, our manager will calculate them for your project and the pipeline's pressure category.

Visually, a gas pipe is black with a yellow longitudinal stripe (or fully yellow in small diameters), whereas water pipes are marked blue. The yellow marking is a mandatory GOST identifier for a gas line — it lets you unambiguously recognise the pipe in the trench and avoid confusing networks during laying and repair.

Beyond colour, gas pipes are made to a separate standard, ST RK GOST R 50838-2011 / ST RK ISO 4437-2014, with stricter requirements for material and wall. Only virgin PE100 with confirmed quality is used for gas — recycled feedstock is not allowed for gas pipelines.

Pipe-Plast gas pipes are made of PE100 polyethylene — a modern pressure material with high resistance to internal pressure and a long service life. PE100 retains its properties at sub-zero temperatures, which matters for underground laying in Kazakhstan's climate.

Polyethylene does not corrode, scale up or require cathodic protection, unlike steel gas lines. The design service life of a PE100 gas pipe is at least 50 years, which lowers network maintenance costs over the whole operating period.

Polyethylene gas pipelines are laid below the frost line, with a sand bed and a warning tape marker. A protection zone is established along the pipeline, within which excavation is restricted — a safety requirement taken into account during design.

Gas pipes are joined by butt or electrofusion welding — only with certified equipment and welders qualified for gas networks. Compression fittings are not used for underground gas lines. Pipe-Plast helps select the joining method and equipment for the specific project.