Bell & Gossett HS 601G Pilot Operated Pressure and/or Temperature Steam Regulators Series 2000 - Manual (Page 11)

ADJUSTING PILOTS
Spring/Air Pilots
Adjust spring/air pilot to control the system at desired
pressure. The system pressure can be set for full steam
or partial steam flow.
Full Steam Flow – If the spring pilot is adjusted to the
required reduced pressure while the system is running at
full steam flow, then the reduced pressure will rise
approximately 10% when the system is running at low
steam flow.
Partial Steam Flow – If the spring pilot is adjusted to the
required reduced pressure while the system is running at
5 – 10% of full steam flow, the reduced pressure will fall
(droop) approximately 10% when the system is running at
full steam flow.
Spring Pilot
1. To increase downstream pressure, increase compres-
sion on the adjusting spring by tightening the adjusting
nuts an equal amount.
2. To decrease downstream pressure, release compres-
sion on the adjusting spring by loosening the adjusting
nuts an equal amount.
Air Pilot
1. To increase downstream pressure, increase the outlet
pressure from the air regulator. The pilot should open
at approximately 9 psig (0.62 bar).
2. To decrease downstream pressure, decrease the out-
let pressure from the air regulator.
Temperature Pilot
1. To increase temperature, loosen Allen lock screw and
turn adjusting knob counterclockwise. Then securely
tighten lock screw.
2. To decrease temperature, loosen Allen lock screw and
turn adjusting knob clockwise. Then securely tighten
lock screw.
3. Once system is running, temperature can be set
immediately.
• Insert a thermometer in heated fluid.
• When thermometer (in heated fluid) indicates
temperature is 5˚F (3˚C) below the required
temperature, turn adjusting knob to lower tempera-
ture setting until steam flow stops.
• The calibrated temperature dial provides an approx-
imate setting. If the temperature dial reading is
slightly off from the thermometer reading, the dial
should be recalibrated, as follows:
– Loosen the set screw and turn the indicator and
the mounting collar.
– Retighten the set screw after making the adjustment.
4. Observe the temperature while the system is running.
5. Adjust the sleeve until the desired temperature is
reached.
6. Tighten the dial set screw without turning the adjusting
sleeve.
7. When the temperature setting is complete, use the
Allen head set screw to lock the knob.
Temperature and Spring Pilot Combination
1. With the temperature pilot set to the highest tempera-
ture setting, adjust the spring pilot as noted above.
2. Adjust the temperature pilot according to instructions
above.
Pneumatic Temperature and Pneumatic Air Pilot
Combination
With this combination, steam pressure is limited rather
than controlled. The air regulator upstream of the air pilot
and pneumatic temperature pilots controls the air pilot
pressure setting. Through this combination, the air pilot
limits the steam pressure delivered by the main valve.
Therefore, only the temperature is adjusted.
1. The air supply to the PNT pilot should be set between
18 and 36 psig (1.24 – 2.5 bar).
2. Turn the adjusting knob on the pneumatic temperature
pilot to the approximate desired operating temperature.
3. Insert a thermometer in heated fluid.
4. When the thermometer reaches the desired tempera-
ture, turn the PNT adjusting knob to indicate 9 psig
(0.62 bar) on the PNT pressure gauge.
5. After conditions have stabilized, make adjustments as
necessary.
For steam pressure limits, refer to "Maximum Steam
Pressure from Main Valve" chart, page 9.
MAINTENANCE
Schedule
1. Initially every 2-3 days after start-up until system is
clean.
2. Every 6 months thereafter.
Procedure:
1. Inspect joints for leaks. Tighten bolts to stop leaks.
2. Open blow down valves on strainers.
3. Allow full pressure steam to pass for two minutes.
4. Close the blow down valves.
5. Observe system pressure and readjust if required.
Control of Pressure and/or Temperature
1. Check to see that operating condition initial adjust-
ments are still set.
2. Consider slightly altering the adjustment to see if the
system responds appropriately.
Solenoid Pilot Actuation
• Make sure solenoid is functioning properly.
Strainers
• If screens in Y- strainers or pilot strainers are excessively
dirty, system blowdown should be done once a week.
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