<p>A liquid valve in which the valve member has a convex portion seated against a concave surface of the valve housing into which a liquid inlet passage opens. A sealing member is positioned in the inlet passage, has an opening formed therethrough to permit the passage of liquid and is urged by liquid pressure in the inlet passage toward the valve member. The valve member is formed with an elongate slot and is movable between an off position closing the inlet passage and a plurality of on positions where the slot interconnects the inlet passage and an outlet passage extending through the valve housing. The valve member is shaped proximate the slot so that valve structure prevents the displacement of the sealing means due to liquid pressure while maximizing liquid volume flow in the on positions.</p>
