Johnson Controls GS-20 Series Installation Sheets Manual page 11

GS-_ _1_
(On/Off
with Flow
Adjustment)
G—GS-20/25 and GS-40/45 Series Single-block Multi-function Gas Control Valves Technical Bulletin 11
Adjustments
IMPORTANT: All adjustments must be made in conjunction with the
gas appliance and in accordance with the appliance
manufacturer's instructions. Only authorized
personnel should make adjustments. See each valve
model version for specific adjustments.
!
WARNING: Explosion hazard. The minimum flow rate of the
valve must not be adjusted below the minimum safe
working rate of the appliance.
It is recommended that the flange pressure tap connections be used to
monitor the inlet and outlet valve pressure while performing each of the
specific adjustment procedures. These pressure connections are located on
the inlet and outlet flanges of the valve in the form of a brass spigot,
sealed with a captive brass needle screw. To monitor the inlet or outlet
pressure using these taps, turn the appropriate needle screw in a
counterclockwise direction one or two turns and fit a 9 mm diameter
flexible tube over the spigot. After all valve adjustments have been made,
remove the flexible tube and turn the needle screw in a clockwise direction
until tight, sealing the spigot.
This valve provides manual flow adjustment throughout the full range of
zero to maximum flow. For flow rate adjustment, loosen the unsealed
mounting screw on the plastic adjustment knob at the top of the solenoid
coil. Hand turn the adjustment knob clockwise to decrease or
counterclockwise to increase the flow rate through the valve
(see Figure 6). Tighten the mounting screw to secure the adjustment knob
at the desired flow rate.
Figure 6: Manual Flow Adjustment Knob