The 106-PR and 206-PR series pressure reducing valves are based on the 106-PG or 206-PG main valves.
The pilot valves sense the downstream pressure through a connection at the valve outlet. Under flowing conditions, the pilot reacts to small changes in pressure to control the valve position by modulating the pressure above the diaphragm. The downstream pressure is maintained virtually steady at the pilot set-point.
In typical pressure reducing applications, the reduced port model 206-PR is often the best selection.
For more information on the 106 / 206-PR pressure reducing valve: