Low pressure sensitive valve

A fluid pressure responsive valve comprising:

• a valve body defining an internal chamber, inlet and outlet fluid passages communicating with the chamber at opposite inlet and outlet ends of the body;
• a valve poppet within the chamber for controlling fluid communication between the inlet passage and the chamber;
• the poppet including a stem projecting into the inlet passage to guide the poppet between open and closed positions;
• the poppet including a lip for making line contact with a valve seat surface at the inlet end when the poppet is in the closed position;
• the seat surface being spherically tapered;
• wherein fluid pressure at the inlet end urges the lip into sealing engagement with the seat surface when the poppet is in its closed position.

A valve body defining an internal chamber, inlet and outlet fluid passages communicating with the chamber at opposite inlet and outlet ends of the body;

• a valve poppet within the chamber for controlling fluid communication between the inlet passage and the chamber;
• the poppet including a stem projecting into the inlet passage to guide the poppet between open and closed positions;
• the poppet including a lip for making line contact with a valve seat surface at the inlet end when the poppet is in the closed position;
• the seat surface being spherically tapered;
• wherein the lip has an inner surface that is concavely curved in a direction toward the inlet end.

A fluid pressure responsive valve comprising:

• a valve body defining an internal chamber, inlet and outlet passages communicating with the chamber at opposite inlet and outlet ends of the body;
• a valve poppet within the chamber for controlling fluid communication between the inlet passage and the chamber;
• the poppet including a stem projecting into the inlet passage to guide the poppet between open and closed positions;
• the poppet including a lip for making line contact with a valve seat surface at the inlet end when the poppet is in the closed position;
• the lip having an inner surface that is concavely curved in a direction toward the inlet end;
• the seat surface being concavely curved in a direction toward the outlet end.

A low fluid pressure responsive valve for close tolerance critical pressure applications as a relief or check valve, comprising:

• a valve body defining an internal chamber, inlet and outlet fluid passages communicating with the chamber at opposite inlet and outlet ends of the body, and a valve seat surface adjacent the inlet end;
• a valve poppet within the chamber having open and closed positions for controlling fluid communication between the inlet passage and the outlet passage;
• the poppet comprising a one-piece member composed of a monolithic elastomeric sealing material having an integral annular sealing lip for making line contact with the valve seat surface when the poppet is in a closed position, the poppet further including a stem projecting into the inlet passage such that the wall of the inlet passage guides the poppet between open and closed positions;
• the seat surface being tapered inwardly in a direction toward the inlet passage;
• the lip and seat surface being cooperatively shaped such that a closing force exerted against the poppet from within the chamber causes the lip to be deflected inwardly toward the inlet passage upon contact with the seat surface.