Erection, reconstruction, repair and maintenance of Equipments withHeightened Danger:steam and water heat boilers; pressure vessels; pipelines for steam and hot water; transferring gas mains of steel; gas regulation and gas distribution stations; gas distribution pipelines and gas regulating posts, industrial and building gas installations and burners systems for natural gas; steel pipelines, gas appliances and installations, fuel systems for liquefied hydrocarbon gases; lifting equipment (cranes, el. hoists, trolleys, excavators, etc.).