Non-return valve

A non-return valve including a bank or series of non-return valves of similar construction coupled to one another, each of said non-return valves comprising:

• a valve body including a fluid passageway which defines a fluid inlet and a fluid outlet, the fluid passageway being adapted to allow a flow of fluid from the inlet to the outlet;
• and
• a conical-shaped valve diaphragm having a collapsible aperture defined by a slit which extends across the full width of the diaphragm and passes through a region located at or adjacent to an apex of the diaphragm which is oriented in a downstream direction, and the diaphragm being connected across the fluid passageway and, excluding the slit, being rotationally symmetrical about a longitudinal axis which passes through said apex, the diaphragm tapering in wall thickness toward said apex and further being constructed of a resiliently flexible material wherein, upon insertion of a nozzle through the collapsible aperture, the diaphragm closes about the nozzle to prevent fluid escape whereas, upon retraction of the nozzle, the diaphragm itself, in a collapsed condition, effects closure of the collapsible aperture to prevent fluid flowing in a reverse direction toward the inlet whereas pressure imposed, using the nozzle, on an inlet side of the diaphragm deflects the diaphragm to expose the aperture and allow fluid to flow through the passageway from the inlet to the outlet only.

A non-return valve comprising:

• a valve body including a fluid passageway which defines a fluid inlet and a fluid outlet located on a low pressure and a high pressure side of the valve, respectively, in a closed state of the valve;
• and
• a valve diaphragm having both an inlet and an outlet side, being conically shaped and having a collapsible aperture defined by a slit which extends across the full width of the diaphragm and intersects an apex of the diaphragm,
• wherein the fluid passageway and the valve diaphragm, upon insertion of a nozzle through the collapsible aperture, allow a flow of fluid through the nozzle in a downstream flow direction only from the inlet to the outlet,
• said apex being orientated in the downstream flow direction and being directed toward the high pressure side of the valve in its closed state, and
• said diaphragm being connected across the fluid passageway and being constructed of a resiliently flexible material tapering in wall thickness towards its apex wherein, upon insertion of the nozzle though the collapsible aperture, the diaphragm sealingly forms about the nozzle and wherein, upon retraction of the nozzle, the diaphragm itself initiates closure of the collapsible aperture.