Product Overview | Pressure-Reducing Regulator
ADJUSTING INSTRUCTIONS Pull off the cap and, with a wrench, turn the adjusting screw clockwise to increase outlet pressure (counterclockwise to decrease outlet pressure). The spring, not the screw, moves up and down. To avoid exceeding the spring range, make adjustments only under flow conditions with a pressure gauge on the outlet tap of the regulator. Turning the screw down too tightly can prevent the regulator from closing. Caution: When changing springs, turn adjusting screw counterclockwise to relax spring before removing 3 socket head cap screws.
7349A Pressure-Reducing Gas Regulators are low pressure step down regulators used in industrial combustion ovens and furnaces. They provide a highly accurate and constant supply pressure to fuel gas control components used on burners and pilots regardless of changes in inlet pressure or demand. One of four different color coded springs can be selected for specific outlet pressures ranging from 1 to 24 osi. The 7349A regulators have a maximum inlet operating pressure of 5 psi and can maintain consistent pressures at very low flows making them ideal for high turndown applications.
TABLE A. Pressures and Temperatures. Inlet pressure--5 psig maximum. Outlet pressure--available in 4 ranges, specify:
15 D minimum
Limiting ori fi ce valve
"Y" Spring (yellow) ........................................for 1 to 4 osi range "A" Spring (aluminum)..................................for 3 to 8 osi range "G" Spring (green) .........................................for 7 to 16 osi range "R" Spring (red).........................................for 14 to 24 osi range The standard 7349A Regulator has internal downstream pressure sensing and is suitable for 180°F maximum ambient temperature. For ambients up to 300°F with cool gas flowing, the 7349A- -V Regulator is available with FKM diaphragms. The 7349A is also available with remote downstream sensing as a standard. Specify 7349A- -S. Gas capacities of 7349A- -S and -V Regulators are same as corresponding standard versions. INSTALLATION Mount in horizontal lines with the adjustment spring up. Figure 2 shows a 7349A Regulator with a cross-connected 7218 Regulator. To avoid interaction, allow a run of 15 or more pipe diameters between the regulators. See Figure 6 for installation of 7349A -S regulators. Never locate the remote tap downstream of another regulator or control valve. Be sure pipe downstream of the regulator is adequately sized. Pipe of a larger size than the regulator connection is often necessary. To determine the pipe size needed, see North American Combustion Handbook , Third Edition, Vol. I.
7349A Regulator
7218 Regulator
Impulse line
Turbo blower
Nozzle-mix gas burner
Air control valve
Figure 2. Typical Pipe Arrangement for 7349A and 7218 Regulators.
Bulletin 7349A Page 2
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