Diaphragm valve

A valve for use in a fluid dispensing system, comprising;

• a valve body having an interior cavity;
• a valve stem mounted for axial movement between open and closed positions within said valve body;
• an actuation air passageway having an actuation air inlet and an actuation air outlet, said air inlet adapted to be coupled to a source of pressurized actuation air and said air outlet communicating with said interior cavity;
• a piston element carried by said valve stem and positioned within said interior cavity;
• a substantially flat sealing element secured to said valve stem and axially moveable therewith;
• a liquid inlet, a liquid outlet, and a substantially flat valve seat positioned between said liquid inlet and said liquid outlet, whereby said valve stem and said sealing element are moveable from said closed position to said open position relative to said valve seat when pressurized actuation air is introduced into said interior cavity through said actuation air passageway and acts against said piston element.

A valve assembly for use in a fluid dispensing system, comprising:

• a valve;
• and a liquid dispensing tip connected to said valve, said tip including a hollow dispensing needle;
• said valve including:
• a valve body having an interior cavity;
• a valve stem mounted for axial movement between open and closed positions within said valve body, said valve stem including an actuation air passageway having an air inlet and an air outlet, said air inlet adapted to be coupled to a source of pressurized actuation air and said air outlet communicating with said interior cavity;
• a piston element carried by said valve stem and positioned within said interior cavity;
• a liquid inlet, a liquid outlet, and a valve seat positioned between said liquid inlet and said liquid outlet, whereby said valve stem is movable from said closed position to said open position relative to said valve seat when pressurized actuation air is introduced into said interior cavity through said actuation air passageway and acts against said piston element;
• and
• a tip retaining nut secured to said body, said liquid dispensing tip being retained by said nut;
• said liquid dispensing tip having a hollow needle in fluid communication with said liquid outlet of said valve.