Drum vent valve

Claim 2

A drum vent valve for controllably venting the interior of a drum container to the atmosphere, said valve comprising housing means, said housing means consisting of a cap portion means and a main body portion, each of said portions having an individually associated firearresting screen, means for attaching said cap portion means to said main body portion, said cap portion means and said main body portion forming an upper compartment closed at the top by one of said firearresting screens, said one fire-arresting screen being joined to said cap portion means in a manner which prevents removal of said one screen from said cap means when said valve is serviced in the field, apron means at the bottom of said main body portion for attaching said valve to the drum container, the bottom of said main body portion forming a lower compartment closed at the bottom by the other of said fire-arresting screens, and joined with the interior of said drum, means in said cap for joining the upper compartment to the atmosphere via said one fire-arresting screen, ledge means integral to said body section located between the upper compartment and the lower compartment, said ledge defining a centrally located valve seat passageway connecting said upper compartment and said lower compartment, main pressure relief valve assembly means normally seated within said valve seat passageway to prevent flow therethrough until the lower compartment pressure is a determined amount greater than the upper compartment pressure, aperture means in said ledge coupling said upper compartment to said lower compartment, and vacuum relief plate means located below said ledge and contiguous thereto to normally prevent flow through said aperture means until the upper compartment pressure is a certain amount greater than the lower compartment pressure.

Claim 3

The drum vent valve of claim 1 wherein said main pressure relief valve assembly means comprises means for relieving pressures within the drum slightly in excess of the normal atmospheric pressure without moving said main pressure relief valve assembly from said centrally located valve seat passageway.

Claim 4

The drum vent valve of claim 2 wherein said main pressure relief valve assembly comprises a main pressure relief valve stem shaped to block said valve seat passageway, said valve stem having a stem passageway therethrough connecting said upper and lower compartments, first orifice means at the bottom of said valve stem passageway, said first orifice means terminating in a valve seat at the top part thereof, first ball valve means normally located within said seat to block said first orifice means, means for maintaining said first ball valve means in said seat until the pressure in said stem passageway is a required amount below the pressure in said first orifice for enabling the passage of fluids through said stem passageway, and blocking means for preventing the passage of fluids through said stem passageway even with said first ball valve means lifted away from said first orifice means, said blocking means operated responsive to a sufficient flow of fluids through said passageway.

Claim 5

The drum vent valve of claim 3 wherein said blocking means comprises second ball valve means, said second ball valve means held in a normally nonblocking posItion by gravity and moved to a blocking position by Bernoulli forces.

Claim 6

The drum vent valve of claim 3 wherein a chamber is provided as a part of said passageway, said chamber having second orifice means leading to said upper compartment, valve seat means at the bottom portion of said second orifice means, and wherein said blocking means comprises second ball valve means normally located under force of gravity at the bottom of said chamber and shaped to fit within said second orifice means to block said passageway, port means formed in the walls of said chamber only over the top of said second ball valve in said normal location and joining said chamber to said passageway, and said ports located so as to cause said second ball valve means to be moved into said valve seat of said second orifice means to block said second orifice means responsive to a sufficient flow of fluids through said passageway and for maintaining said second ball valve means in said second orifice responsive to sufficient pressure differential between the upper compartment pressure and the lower compartment pressure.

Claim 7

The drum vent valve of claim 2 wherein said valve stem comprises plate means normally located contiguous to said valve seat passageway and a section disposed below said plate means, said section disposed below said plate means comprising a plurality of radial fins whereby said valve stem is maintained in a stable position during the movement of the valve stem.

Claim 8

The drum vent valve of claim 6 wherein first resilient means are provided for maintaining said valve stem within said valve seat passageway under normal pressure conditions, and wherein second resilient means are provided for maintaining said plate means contiguous to the bottom of said ledge means under normal pressure conditions.

Claim 9

A drum vent valve for controllably venting the interior of a drum container to the atmosphere, said valve comprising housing means, said housing means consisting of a cap portion means and a main body portion, means for attaching said cap portion means to said main body portion, said cap portion means and said main body portion forming an upper compartment, apron means at the bottom of said main body portion for attaching said valve to the drum container, the bottom of said main body portion forming a lower compartment joined with the interior of said drum, means in said cap for joining the upper compartment to the atmosphere, ledge means integral to said body section located between the upper compartment and the lower compartment, said ledge defining a centrally located valve seat passageway connecting said upper compartment and said lower compartment, main pressure relief valve assembly means normally seated within said valve seat passageway to prevent flow therethrough until the lower compartment pressure is a determined amount greater than the upper compartment pressure, aperture means in said ledge coupling said upper compartment to said lower compartment, vacuum relief plate means located below said ledge and contiguous thereto to normally prevent flow through said aperture means until the upper compartment pressure is a certain amount greater than the lower compartment pressure, a chamber being provided as a part of said passageway, said chamber having second orifice means leading to said upper compartment, valve seat means at the bottom portion of said second orifice means, and wherein said blocking means comprises second ball valve means normally located under force of gravity at the bottom of said chamber and shaped to fit within said second orifice means to block said passageway, port means formed in the walls of said chamber only over the top of said second ball valve in said normal location and joining said chamber to said passageway, and said ports located so as to cause said second ball valve means to be moved into said valve seat of said second orifice meAns to block said second orifice means responsive to a sufficient flow of fluids through said passageway and for maintaining said second ball valve means in second orifice responsive to sufficient pressure differential between the upper compartment pressure and the lower compartment pressure.

Claim 10

A drum vent valve for controllably venting the interior of a drum container to the atmosphere, said valve comprising housing means, said housing means consisting of a cap portion means and a main body portion, means for attaching said cap portion means to said main body portion, said cap portion means and said main body portion forming an upper compartment, apron means at the bottom of said main body portion for attaching said valve to the drum container, the bottom of said main body portion forming a lower compartment joined with the interior of said drum, means in said cap for joining the upper compartment to the atmosphere, ledge means integral to said body section located between the upper compartment and the lower compartment, said ledge defining a centrally located valve seat passageway connecting said upper compartment and said lower compartment, main pressure relief valve assembly means normally seated within said valve seat passageway to prevent flow therethrough until the lower compartment pressure is a determined amount greater than the upper compartment pressure, aperture means in said ledge coupling said upper compartment to said lower compartment, vacuum relief plate means located below said ledge and contiguous thereto to normally prevent flow through said aperture means until the upper compartment pressure is a certain amount greater than the lower compartment pressure, a chamber being provided as a part of said passageway, said chamber having second orifice means leading to said upper compartment, valve seat means at the bottom portion of said second orifice means, and wherein said blocking means comprises second ball valve means normally located under force of gravity at the bottom of said chamber and shaped to fit within said second orifice means to block said passageway, port means formed in the walls of said chamber only over the top of said second ball valve in said normal location and joining said chamber to said passageway, and said ports located so as to cause said second ball valve means to be moved into said valve seat of said second orifice meAns to block said second orifice means responsive to a sufficient flow of fluids through said passageway and for maintaining said second ball valve means in second orifice responsive to sufficient pressure differential between the upper compartment pressure and the lower compartment pressure.