CPC Subgroup
F17B 1/26 with flexible walls, e.g. bellows (connection of valves to inflatable elastic bodies B60C29/00)
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) > of dry type > with flexible walls, e.g. bellows (connection of valves to inflatable elastic bodies B60C29/00)