Valve for the periodic and cyclic or otherwise intermittent release of a fluid is described along with an irrigation sprinkler incorporating the valve. The valve opens when a critical pressure level is reached in a reservoir attached to the valve, thereby permitting a portion of the fluid contained within the reservoir to be released through the valve. As the fluid is released, the pressure in the reservoir decreases. The valve does not close until the pressure level in the reservoir reaches a second pressure level that is below the critical pressure level. When the reservoir is refilled from a pressurized source at a controlled rate that is less the rate at which the fluid is expelled through the valve when open, the valve will cycle repetitively.