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 valve diaphragm being connected across the fluid passageway and including a collapsible aperture, the valve diaphragm being constructed of a resiliently flexible material and being configured wherein 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 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 membrane being permeable in one direction only, said membrane comprising a panel or blanket of collapsible diaphragms each including a collapsible aperture and being constructed of a resiliently flexible material which is configured wherein each of the diaphragms themselves effects closure of the collapsible aperture to prevent fluid flowing in a reverse direction whereas pressure imposed on an upstream side of the membrane deflects one or more of the diaphragms to expose the corresponding aperture and allow fluid to flow across the membrane in said one direction only.

A pressure relief 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;
• and
• a valve diaphragm in the form of a conical-shaped diaphragm having a collapsible aperture located at or adjacent its apex which is oriented in a downstream flow direction and directed toward the high pressure side of the valve, said diaphragm being connected across the fluid passageway and being constructed of a resiliently flexible material wherein the diaphragm initiates closure of the collapsible aperture, the diaphragm being configured whereby excessive pressure on the high pressure side of the valve effects deflection of the diaphragm to expose the collapsible aperture to temporarily vent fluid from said high pressure side.