Double-layer pipes for the construction of gas networks manufactured in SDR 17 for diameters DN 75-500 and SDR 11 for diameters DN 25-500 according to the PN-EN 1555:2-2012 standard. They are made of high-density polyethylene of the PE 100-RC HERLKULES class characterised by high resistance to impact loads and a wide range of operating temperatures, thus the network can be laid during most months of the year. The pipes are intended for the construction of pipelines for the distribution of gaseous fuels. Available in coils or straight, depending on the nominal diameter. Depending on the diameter and application, the pipes can be joined by butt welding or electrofusion welding. They are available in coils or straight, depending on the nominal diameter.