Abstract: A pressure relief valve controls the pressure in a pressure chamber of a sprayer. The pressure chamber is inside a tank from which liquid to be sprayed is pumped into the pressure chamber and pressurized. The pressurized liquid is released from the chamber via a hose and nozzle for spraying. The pressure relief valve has a holder or body with an opening therethrough. A sleeve is movable in the body and contains a compression spring. The spring is compressed against a lower end of the body by a cap which is rotatable about the holder and engages the spring. The sleeve captures a ball providing a valve against a valve seat in the holder. The sleeve constrains the motion of the valve and the spring so that the valve opens at the release pressure corresponding to the compression of the spring by the cap, and the release pressure is the same, even with repeated openings and closings of the valve. Leakage through the valve is also substantially eliminated.