ITT
Engineered Valves, LLC
Page 6 of 22
Technical Manual No. IOT1000P Effective 8/31/2018
REV LEVEL B
Operational Note:
While in the Fire position there is an operational advantage in
leaving the Purge solenoid energized while in Fire. In this scenario both actuator
cylinders will be pressurized. Doing so will prevent the valve from traveling back
to the Closed position causing a momentary loss in Purge pressure. This will help
in ensuring the burner flame stays lit as the oil valve closes and the slug of oil
remaining in the down stream piping of the valve is evacuated by the purge
media. Maintaining a constant pressure on this slug of oil will ensure it is burned
completely. If the Purge cylinders were not energized with the Fire cylinders the
atomizing valve would close and then open back up for Purge. This will cause a
momentary drop in atomizing pressure causing the flame to suck back or possibly
extinguish before the remaining slug of oil is evacuated.
C.
Purge: Atomizing and Purge Media Flowing, Oil Off
Energizing only the purge solenoid moves the atomizing stem to the purge
position. In this position the atomizing plug is positioned between, but not in
contact with the atomizing and purge seats. Accordingly, the atomizing stem is
not in contact with the oil plug, therefore the oil valve remains in the closed
position. The atomizing media flows from the atomizing inlet to both, the
atomizing and oil outlets, purging or clearing any oil which, remains in the
downstream oil piping. There is no oil flow in the purge position and the oil valve
POC switch is made. Both the valve open and valve closed limit switches are
deactuated.
D.
Notes
Some installations may require tip warm up prior to light-off. This can be
accomplished by commanding the valve to "Purge" for a period of time before
commanding to "Fire". Atomizing steam then passes down both atomizing and
fuel lines, warming up the tip in preparation for ignition. Due to the stacked
tandem cylinder design of the actuator, when both "Fire" and "Purge" solenoids
are energized, the "Fire" command will override and the assembly will shift to the
full open or "Fire" position. The Fire Solenoid must be de-energized for the valve
to move to the purge position.
