Ключевые слова:
Gas pipelines, Gaseous fuels, Polyethylene, Plastic pipelines, Pipework systems, Pipelines, Thermoplastic polymers, Plastics, Gas pipes, Pipes, Pipe couplings, Pipe fittings, Gas-pipe fittings, Gas valves, Valves, Quality control, Assessed quality, Quality assurance, Quality assurance systems, Conformity