Container with primary and secondary pressurised compartments, typically bottle containing capsule, with valve sealing capsule

摘要

Valve stem 51 normally seals orifice 52. On releasing cap 41 from bottle 40 pressure in space 55 in the bottle is reduced to atmospheric. Additionally, stem 51 is caused to move away from orifice 52 and fluid then flows from chamber 56 into space 55.