Vacuum demand valve

A valve comprising:

• a sidewall;
• a first retainer comprising a first opening;
• a second retainer comprising a second opening, the sidewall and the first and second retainers defining a housing;
• a flexible diaphragm located within the housing, responsive to an external force, and dividing the housing into first and second chambers, the first chamber including a vent;
• and
• a plunger fixedly connected to the flexible diaphragm and responsive to a movement of the flexible diaphragm, the plunger slidably supported by the first and second openings in the first and second retainers, respectively, and located at least partially within the housing, the plunger including a vacuum passage and a fluid passage, the fluid passage sealable against a portion of the first retainer and the vacuum passage in communication with the second chamber wherein a vacuum pressure provided via the vacuum passage causes the movement of the diaphragm.

A tubing for delivering a fluid substance from a container to a user, the tubing comprising:

• a proximal end defining an inlet;
• a distal end defining an outlet;
• an intermediate segment between the proximal end and the distal end;
• a passageway between the proximal end and the distal end wherein the inlet and outlet are generally coaxial and a fluid substance can flow from the proximal end to the distal end;
• and
• a valve member located along the intermediate segment, the valve member being moveable between an open condition and closed condition, wherein when the valve is in a closed condition fluid flow from the proximal end to the distal end is stopped and when the valve is in an open condition the flow of the fluid substance from the proximal end to the distal end is unstopped, the valve member being biased in the direction of the distal end in the closed condition and responsive to an external force provided by a user in the form of a partial vacuum through the passageway for moving the valve member towards the proximal end into the open condition.

A valve comprising:

• a housing having an outlet chamber defining an outlet opening;
• a diaphragm positioned within the intermediate chamber defining a first chamber and second chamber;
• a plunger connected to the diaphragm and slidably supported within the housing, the plunger having a vacuum duct having a first end in communication with the first chamber and a second end in communication with the outlet opening, the plunger further having a passageway having a first end and a second end in communication with the outlet chamber;
• wherein the diaphragm is moveable from a first position wherein the first end of the passageway is obstructed and a second position wherein a flowable substance can flow from the inlet chamber to the outlet chamber through passageway and wherein the diaphragm is moveable by a partial vacuum applied through the vacuum duct.

A tubing for delivering a fluid substance from a container to a user, the tubing comprising:

• a proximal end defining an inlet;
• a distal end defining an outlet;
• an intermediate segment between the proximal end and the distal end;
• a passageway between the proximal end and the distal end wherein the inlet and outlet are generally coaxial and a fluid substance can flow from the proximal end to the distal end;
• and
• a retainer positioned between the intermediate segment and the proximal end of the tubing wherein the retainer extends into the passageway;
• and
• a valve member located along the intermediate segment for controlling fluid flow through the tubing, the valve member having a closed condition wherein the valve member engages the retainer to stop the flow of fluid substance from the proximal end to the distal end and an open condition wherein the flow of the fluid substance from the proximal end to the distal end is unstopped.