Casings of metal for oilwells; Ducts and pipes of metal for central heating installations; Ducts of metal for ventilating and air-conditioning installations; Junctions of metal for pipes; Penstock pipes of metal; Pipe muffs of metal; Pipework of metal; Valves of metal other than parts of machines including those from alloy steel and titanium; Valves of metal, other than parts of machines; Water-pipe valves of metal