摘要 |
A valve device to control fluid supplied to a tank. The valve device includes a fluid inlet, a fluid outlet to expel fluid to the tank, a valve seat, defining an opening through which fluid is adapted to flow from the inlet to the outlet, a valve member, movable relative to the valve seat between an open position and a closed position, and, a control mechanism to operate said valve device. The control mechanism includes a control chamber, a fluid passageway between the control chamber and the inlet, a flow control element within the fluid passageway, a relief valve, movable between an open position and a closed position to selectively expel fluid from the control chamber to a relief port, and, a relief valve activation mechanism, to control the operation of the relief valve according to an amount of fluid in the tank. |