A valve device to control fluid supplied to a tank (123). The valve device includes a fluid inlet (101), a fluid outlet (120) to expel fluid to said tank (123), a valve seat (119), defining an opening through which fluid is adapted to flow from said inlet (101) to said outlet (120), a valve member (107), movable relative to said valve seat (119) between an open and a closed position, and, a control means to operate said valve device. The control means includes a control chamber (103), a fluid passageway (102) between said control chamber (103) and said inlet (101), a flow control element (104) within said fluid passageway (102), a relief valve (106), movable between an open and closed position to selectively expel fluid from said control chamber (103) to a relief port (121), and, a relief valve activation means, to control the operation of said relief valve according to the amount of fluid in said tank (123). The valve device (200) may be constructed in a multi-part form, including a main body portion (201) and a relief portion (202).