Ridutor of three -way direct action to variable calibration, the PZM3 valve is a three -way pressure reducer with direct action, in a modular version. The valve is normally open and the hydraulic fluid crosses it freely. The cursor is subject to the pressure of the pipe P and on the other to the adjustment spring. When the pressure in the PDUE P exceeds the value set by the spring, the valve ends until the pressure in P (reduced) equals the calibration value. The three -way structure protects the secondary circuit from overpressure, allowing the reverse flow from the actuator to the exhaust line to the tank. The valve is supplied with hexagonal head adjustment screw.