Burner Operation and Control
2-12
750-211 (revised 2009)
Promethean Boilers, Model 4WI Manual
In addition to the components of the fuel oil controller mentioned in this section, the following are used with a
heavy-oil-fired burner:
7. Steam Heater Check Valve Prevents oil contamination of the waterside of pressure vessel should any leakage
occur in the oil heater.
8. Steam Trap Drains condensate and prevents loss of steam from the steam oil heater. Conden-
sate must be piped to a safe point of discharge.
9. Check Valve (Discharge) Prevents air entry during shutdown periods when cooling action may create vac-
uum within steam heater.
10. Steam Heater Pressure Reg-
ulator
Adjust to provide reduced (usually less than 15 psi) steam pressure to the heater to
properly maintain the required fuel oil temperature. The regulator and the pressure
gauge are not furnished on 15 psi units.
11. Steam Heater Solenoid
Valve
A normally open solenoid valve opened by the steam oil heater thermostat to allow
flow of steam to the steam heater to maintain temperature of fuel oil.
12. Steam Pressure Gauge Indicates steam pressure entering the heater.
13. Oil Relief Valve Allows release of excessive pressure to the return side of the oil line piped to the
tank.
14. Low-Oil-Temperature
Switch
Thermostatic switch that prevents burner from starting, or stops burner firing if
fuel oil temperature is lower than required for oil burner operation.
15. Oil Supply Pressure Gauge Indicates fuel oil pressure in the oil heater and supply pressure to the fuel oil con-
troller’s pressure regulator.
16. Oil Return Oil return from the fuel oil controller.
17. Heated Oil to Burner Heated oil for heavy oil firing.
18. Fuel Oil Strainer Oil to burner cleaned through strainer.
Component Description
A. High-Oil-Temperature
Switch (optional)
Switch contacts open when fuel oil temperature raises above a selected temperature.
Switch will interrupt the limit circuit in the event fuel oil temperature rises above
the selected point.
B. Hot Water Oil Heater
Thermostat
Used on a hot water boiler to sense fuel oil temperature and control the starting and
stopping of the booster water pump.
C. Booster Water Pump Started and stopped by the hot water thermostat to regulate the flow of hat water
through the hot water oil heater to maintain temperature of fuel oil.
D. Fuel Oil Thermometer Indicates temperature of fuel oil being supplied to the fuel oil controller.
E. Back Pressure Valve For adjustment of oil pressure on the downstream side of the metering valve. Also
regulates rate of return oil flow.
F. Oil Return Pressure Gauge Indicates oil pressure on the return side of the fuel oil controller.
G. Manual Bypass Valve Provided as a time saver in establishing oil flow. When open, it permits circulation
of oil through the supply and return lines. The valve must be closed prior to initial
light off.
Component Description
To Next Page
Loading...
