Metal pipes for liquid and gas transfer; alloys of common metals; water pipes made of copper; copper pipes for use in hot and cold water supply systems; copper pipes for use in solar collectors for heating; copper pipes for use in solar water heaters; copper pipes for central heating installations; copper pipes for liquid and gas transfer; copper pipes for sprinkler systems for fire protection; copper pipes for ventilating and air-conditioning installations; couplings and joints of metal for ...