Abstract: An intake relief valve is provided with a gate in the form of a ball cock which rotates in a horizontal plane on a vertical axis by means of a swivel pin and sector gear turned by a worm gear and wheel. The gear box housing is at the top of the valve and its exposed upper surface carries the markings "close", "1/4", "1/2", "3/4", and "open". The swivel pin carries a needle indicator, exterior of the gear box, to move from one marking to the other to show the degree of opening of the valve. The ball cock closes the valve ports, one of which is screened. It forms an annular compartment with the valve housing through which liquid may pass to the pressure relief valve in the lower portion of the valve whether the ball cock is in open or closed position.