Reset relief valve with a body having an inlet port, an outlet port, and an interior wall partially defining an enclosed chamber. A piston disposed in the body and moveable between a first position at which the piston is disposed in fluid flow-blocking relationship between the inlet port and the outlet port of the body and a second position at which the piston is removed from that position. The piston having a head with opposed end surfaces one of which defines a portion of the enclosed chamber and at least one fluid flow passageway extending through the head and providing fluid communication. A preferred embodiment includes the crank assembly with cross bar support and a T-bar to prevent downward movement of the disc.