CPC Subgroup
F17B 1/007 with telescopically movable ring-shaped parts (F17B1/10 takes precedence; sealing of rings 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 telescopically movable ring-shaped parts (F17B1/10 takes precedence; sealing of rings F17B1/04)