Abstract: In the preferred and illustrated embodiment, a low pressure safety relief valve and pilot for the safety relief valve is particularly adapted for use with steam. The pilot incorporates two diaphragms, one being a sense diaphragm responding to a pressure setting opposed by an adjustable spring, and the second being a boost diaphragm which assists opening of the pilot to a fully open position. The pilot includes an inlet supply passage communicating first through an adjustable and then a fixed orifice to define controllable pressure drops, and forms a control pressure applied to the dome of the safety relief valve. The dome pressure closes a movable piston, subject to differential areas. The safety relief valve is opened by dropping dome pressure at such time as the safety relief valve is controllably opened. The pilot valve, being equipped with a sense diaphragm and selectively boosted by a differential force acting across the boost diaphragm, drops the dome pressure, by venting to atmosphere.