Series 91000
••• Self-Operating Regulators
Operation, Installation & Maintenance Manual
Page 7
Using the supplied
1
/
4
” rod, turn the 1
3
/
4
” adjusting screw to a position on the “0 to 8” reference scale to a
position that approximately corresponds to the relative position of the desired control point within the adjustable
range. The “V” slot in the adjusting screw is intended as the index line for recording the setting number in
maintenance logs. To raise the control point, turn the adjusting screw from left to right up toward
“HIGH”
marked on the reference scale. To lower the control point, turn the adjusting screw from right to left down
toward
“LOW”
marked on the reference scale.
This adjustment must be done at system operating
pressure to balance the stem thrust load for proper regulation.
DO NOT TURN THE SMALL HEX STEM JAM NUTS.
THIS IS A CRITICAL SETTING FOR THE PROPER SEATING & STROKE OF THE REGULATOR.
PLACING THE REGULATOR INTO OPERATION AND SETTING THE CONTROL POINT
Figure 1:
(Model 91000 shown)
CAUTION:
DO NOT TURN THE ADJUSTING
SCREW BELOW THE “0” MARK
When the downstream units are ready to receive flow, close the by-pass valve and open all upstream
supply valves slowly to allow gradual start-up.
Observe the controlled temperature after it stabilizes and re-adjust the adjusting screw as required to obtain
the desired control point. Initial over shooting may occur until the system approaches equilibrium. Allow
sufficient time for correction to take place after each adjustment before further changing the setting.
Be certain that all manual valves in the main flow line are fully open and not restricting the flow.
Also be sure all downstream units are passing the flow properly.
Actuator
Reference Scale
1/4” Adjusting Rod
Valve Body Assembly
Adjusting Screw
Jam Nuts
Thermowell
Sensing Bulb
