Taking advantage of the direct relationship between saturated steam pressure and temperature can be simple, like our pressure reducing valve station example. But when the change in pressure requires a steep reduction, especially to a very low pressure, using a two-stage regulator setup can offer more accurate results.
In a system like the one shown, the saturated steam supply (P1) could be 120 psi, but the process may need only 10 inches of water column. The first regulator’s role is to reduce the pressure to an outlet (P2) value that is manageable for the second regulator’s process, like a P2 of 10 psi, to control accurately. That 10 psi enters the second regulator, which is set for a P2 of 10 inches of water column.
By reducing the pressure in two stages, wear and tear is reduced, and more accurate results are possible. The gate valve between the two regulators is optional, and allows for isolate for maintenance.
Learn more about controlling temperature in saturated steam applications.