Johnson Controls UL Listed GS-20 Series Manual page 11

G—UL Listed GS-20/25 and GS-40/45 Series Single-block Multi-function Gas Control Valves Technical Bulletin 11
To set the start gas position, energize the solenoid coil to open the valve
seats. Remove the pressure tap plug (see Figure 8) located below the gas
outlet pipe connection and measure the start gas pressure. The P
adjustment scale indicates the factory-set start gas pressure (see Figure 9);
therefore, a subsequent fine adjustment may be necessary. Use the
hexagonal tool provided (or an acceptable Allen wrench) to adjust the P
scale and obtain the desired start gas pressure.
Figure 8: Valve Outlet Pipe Connection
Figure 9: P and P
ST
The start gas pressure (P
plug is replaced and tightened. The pressure then rises to the setpoint (P
IMPORTANT: P must be greater then P
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operate properly.
Once the desired start gas pressure has been obtained, the outlet pressure
(P ) can be adjusted. For outlet pressure position adjustment, energize the
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solenoid coil to open the valve seats. Remove an outlet pressure tap plug
from the valve body and measure the servo pressure regulator performance
and timing characteristics (see Figure 10). The P
indicates the factory-set outlet pressure (see Figure 9), which can be
adjusted using the hexagonal tool provided (or an acceptable Allen
wrench) to obtain the desired servo pressure regulator performance and
timing characteristics.
6
2 10
P
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P
5-50
ST
Adjustment Scales (Metric Shown)
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) remains at the set level until the pressure tap
ST
in order for the valve to
ST
ST
P ressure
Ta p P lug
adjustment scale
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ST
).
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