Valve assemblies

A method of manufacturing an exhalation valve assembly comprising the steps of:

• (a) providing a valve body component defining at least an inlet portion of a fluid conduit of the valve assembly having an inlet and an outlet;
• (b) providing at least one valve seat component defined by an upstanding collar at the periphery of an opening into an exhalation port comprising, and defining a configuration of, at least an uppermost edge of the upstanding collar adapted to be engaged by a flexible membrane for controlling the flow of fluid through the outlet of the fluid conduit of the valve assembly;
• and
• (c) engaging the at least one valve seat component with the valve body component, such that the inlet portion of the fluid conduit extends from the inlet of the fluid conduit to the valve seat component, and the fluid conduit comprises an outlet portion that extends from the valve seat component to the outlet of the fluid conduit,
• wherein the valve assembly has a control chamber adapted to be supplied by a ventilator, during use, with a gas under pressure, and the flexible membrane defines a wall of the control chamber and is disposed adjacent to the uppermost edge of the upstanding collar, such that the exhalation valve assembly has a release pressure for the outlet that is determined by the pressure of one or more gases within the control chamber.

An exhalation valve assembly comprising a fluid conduit having an inlet and an outlet, an exhalation port, a control chamber adapted to be supplied by a ventilator, during use, with a gas under pressure, a flexible membrane that defines a wall of the control chamber and a valve seat component defined by an upstanding collar at the periphery of an opening into the exhalation port, the flexible membrane being disposed adjacent to an uppermost edge of the upstanding collar, the flexible membrane having an engaged position with respect to the uppermost edge of the upstanding collar to provide a closed configuration of the exhalation valve assembly and a partially disengaged position with respect to the valve seat to provide an open configuration of the exhalation valve assembly, and the exhalation valve assembly has a release pressure that is determined by the pressure of one or more gases within the control chamber, wherein the exhalation valve assembly is defined by at least a valve body component and a valve seat component engageable therewith, the fluid conduit of the exhalation valve assembly comprising an inlet portion that extends from the inlet of the fluid conduit to the valve seat component, and an outlet portion that extends from the valve seat component to the outlet of the fluid conduit, the valve body component defining at least part of the inlet portion of the fluid conduit, and the valve seat component comprising, and defining a configuration of, at least the uppermost edge of the upstanding collar.