The SR Series Pressure Reducing Regulator is designed for industrial furnaces and heating applications. These regulators will maintain a constant outlet pressure over a wide range of flows even if the inlet pressure varies.
Several spring ranges are available, from 4'' W.C. to 3 psig. Pilot loaded regulators, the SR-PC series, are also available for higher pressures and flows.
Standard construction is for clean fuel gases including Natural Gas, Propane, Butane and other Hydrocarbon fuels. Special construction is available for gases such as Coke Oven Gas.
The standard model is limited to fluids at temperatures of 150°F. Special models are available for temperatures to 700°F.
The standard design has internal compensation. For capacities greater than listed in the table the regulator can be supplied with external compensation.
The larger size Reducing Regulators, with 48 osi spring, SR-20-PC and SR-24-PC (2-1/2'' through 3'') and with 80 osi spring SR-12-PC through SR-24-PC (1-1/2'' through 3''), have very large main diaphragm areas which make spring loading above 16 osi (1 psig) impractical.
The 48 osi (white spring) and 80 osi (blue spring) ranges of outlet pressure on these sizes are obtained by pilot loading the main regulator with system gas. An SR 6-48 or 80 Reducing Regulator is connected so that its outlet pressure is applied to the upper diaphragm chamber of the main regulator. A constant flow limiting orifice permits a flow of 50 to 100 SCFH through the pilot regulator.
The force balance required on the main regulator diaphragm is maintained between the top loading pressure (the outlet pressure of the pilot regulator) and the system delivery pressure. The outlet compensator operates in the same manner as the standard spring loaded units.
CAPACITY TABLE Model Number Pipe Size SCFH Gas Flow @ 14.0" W.C. Pressure Drop MFD. 0.4 Sp. Gr. NAT. 0.6 Sp. Gr. AIR 1.0 Sp. Gr. L.P. 1.5 Sp. Gr. SR 6 3/4" 1,230 1,000 780 630 SR 8 1" 2,500 2,000 1,500 1,200 SR 12 1-1/2" 4,900 4,000 3,100 2,500 SR 16 2" 9,400 7,700 6,000 4,900 SR 20 2-1/2" 12,300 10,000 7,800 6,300 SR 24 3" 21,000 17,000 13,000 11,000