F17B1/00	7	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)	F17B1/00	F17B1/00		400
F17B1/007	8	with telescopically movable ring-shaped parts (F17B1/10 takes precedence; sealing of rings F17B1/04)	F17B1/007	F17B1/007		92
F17B1/013	8	with movables discs (F17B1/10 takes precedence; sealing of discs F17B1/04)	F17B1/013	F17B1/013		132
F17B1/02	8	Details	F17B1/02	F17B1/02		251
F17B1/04	9	Sealing devices for sliding parts (in general F16J15/00)	F17B1/04	F17B1/04		355
F17B1/06	10	using sealing liquids	F17B1/06	F17B1/06		68
F17B1/08	10	using resilient materials for packing, e.g. leather	F17B1/08	F17B1/08		134
F17B1/10	9	Guiding moving parts	F17B1/10	F17B1/10		39
F17B1/12	9	Gas admission or discharge arrangements	F17B1/12	F17B1/12		160
F17B1/14	9	Safety devices, e.g. prevention of excess pressure	F17B1/14	F17B1/14		207
F17B1/16	8	of wet type	F17B1/16	F17B1/16		18
F17B1/18	9	bell-shaped	F17B1/18	F17B1/18		14
F17B1/20	9	telescopic	F17B1/20	F17B1/20		6
F17B1/22	10	spirally-guided	F17B1/22	F17B1/22		
F17B1/24	8	of dry type	F17B1/24	F17B1/24		81
F17B1/26	9	with flexible walls, e.g. bellows (connection of valves to inflatable elastic bodies B60C29/00)	F17B1/26	F17B1/26		161
