CPC Subgroup
F17B 1/013 with movables discs (F17B1/10 takes precedence; sealing of discs F17B1/04)
Full Title
Gas-holders of variable capacity (large containers in general B65D88/00; storing fluids in natural or artificial cavities or chambers in the earth B65G5/00) > with movables discs (F17B1/10 takes precedence; sealing of discs F17B1/04)