Vacuum demand valve

A valve comprising:

• a housing having a passageway having an inlet opening and an outlet opening, and an intermediate segment therebetween, wherein a flowable material can flow through the passageway from the inlet opening to the outlet opening;
• and
• a stop having a channel therethrough the channel having an inlet and an outlet, the stop being moveable in the intermediate segment from a first position wherein the channel is not in communication with the outlet opening, to a second position wherein the channel is in communication with the inlet opening and the outlet opening and the channel inlet and outlet are closed by the housing wherein flowable material can flow through the passageway, the stop being biased to the first position;
• a vacuum chamber located in the intermediate segment;
• a vacuum duct in communication with the vacuum chamber wherein a partial vacuum applied to the vacuum duct moves the stop to the second position wherein flowable material can flow through the passageway.

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

• a proximal end having a first conduit;
• a distal end having a fluid conduit and vacuum conduit in communication with a vacuum chamber defined by the tubing;
• an intermediate segment between the proximal end and the distal end;
• a passageway between the proximal end and distal end wherein a fluid substance can flow therethrough;
• and
• a valve member located along the intermediate segment, the valve member defining a second conduit therethrough and having a closed condition wherein the passageway is not in communication with the distal end and the flow of the fluid substance is stopped and the fluid conduit is in communication with the vacuum chamber and an open condition wherein the flow of the fluid substance from the first conduit to the second conduit is unstopped and the fluid conduit is not in communication with the vacuum chamber, the valve member being biased in the closed condition and responsive to an external force provided by a user in the form of a partial vacuum provided by the user through the vacuum conduit for placing the valve member in the open condition.

A valve comprising:

• a housing;
• a first fluid conduit in fluid communication with the housing;
• a valve member mounted for reciprocating movement within the housing and separating the housing into a vacuum chamber and vent chamber, the valve member having a second fluid conduit therethrough and moveable from a first position where the first fluid conduit is substantially aligned with respect to the second fluid conduit to enable fluid to flow therethrough and wherein the first fluid conduit is not in communication with the vacuum chamber, to a second position, where the first fluid conduit is not in communication with the second fluid conduit;
• and
• a vacuum conduit in fluid communication with the housing wherein the valve member is responsive to a negative pressure applied to the housing through the vacuum conduit to move the valve member from the second position to the first position.