Pressure reducing and sustaining units from Orival – Eurodrip combine the operation of the two pilots to sustain a constant pressure upstream of the valve, and at the same time, reduce the downstream to a preset pressure. Both pilots have spring loaded diaphragms. One pilot is sensitive to upstream pressure and the other to downstream pressure. The valve opens or closes gradually to maintain both required pressures simultaneously.

Pressure reducing units maintain a constant downstream pressure regardless of the upstream pressure or flow rate fluctuations. The set point of reduced pressure is adjustable by a 2-way or 3-way pilot valve. A spring-loaded diaphragm inside the pilot moves according to the downstream pressure changes. The pressure fluctuations are compensated by gradual opening and closing of the valve.