Abstract: An apparatus incorporating a normally-closed check valve mounted on the inlet end of a vapor withdrawal conduit and located in the upper vapor portion of a partially filled pressurized LP gas tank on a recreational vehicle or the like. The outlet end of the vapor withdrawal conduit extends to a point lower and exterior to the volatile liquid container and is connected to a control valve to stop the flow of fluid. As the control valve is opened to allow fluid to pass. Then the pressure in the vapor withdrawal conduit drops. The check valve opens and allows gases from the volatile liquid container to pass down the tube. After the control valve is closed, the pressure in the vapor withdrawal conduit increases till it equals the pressure in the container. The check valve closes and stops the flow of fluid.When the apparatus is used in a movable mode, such as on a vehicle, the check valve is closed, preventing the volatile liquid contained in the container from being splashed into the vapor withdrawal conduit.

Abstract: A maximum liquid level control valve for limiting the flow of liquid petroleum gas into a tank having a valve body, a float pivotally attached to the valve body, a closure flap, a spring acting between the valve body and the closure flap, and a cam device movable by the float. The control valve which is mounted to a flange welded to the side wall of the tank has a valve seat and a passage for liquid to flow through the valve body into the tank. The closure flap is movable toward the valve seat to a closed position and away from the valve seat to an open position. The closure flap is movable to the closed position under incoming liquid pressure. When the liquid level in the tank is below the maximum liquid level, the cam device acts on a stem which is attached to the closure flap. With the cam acting on the stem, the closure flap cannot be moved to the closed position in response to incoming liquid pressure.

Abstract: A maximum liquid level control valve for limiting the flow of liquid petroleum gas into a tank having a valve body, a float pivotally attached to the valve body, a closure flap, a spring acting between the valve body and the closure flap, and a cam device movable by the float. The control valve which is mounted to a flange welded to the side wall of the tank has a valve seat and a passage for liquid to flow through the valve body into the tank. The closure flap is movable toward the valve seat to a closed position and away from the valve seat to an open position. The closure flap is movable to the closed position under incoming liquid pressure. When the liquid level in the tank is below the maximum liquid level, the cam device acts on a stem which is attached to the closure flap. With the cam acting on the stem, the closure flap cannot be moved to the closed position in response to incoming liquid pressure.