CHAPTER!
GENERAL
DESCRIPTION
AND
PRINCIPLES
OF
OPERATION
(11) Steam
Trap
(Fig. 1·8): Drains condensate
and prevents the loss
of
steam from the steam oil
heater. Condensate must
be
piped
to
a safe point
of
discharge.
(12)
Check
Valve
(Steam Heater Discharge)
(Fig. 1-8): Prevents air entry during shutdown
periods
when
cooling
action
may
create
a
vacuum within the
steam
heater.
(13)
Oil Supply Pressure
Gauge
(Figs.
1·2
and
1-8): Indicates fuel oil pressure in the oil heater
and supply pressure
to the fuel oil controller's
pressure regulator.
(14)
Low
Oil Temperature Switch (Figs. 1-2 and
1-8):
Thermostatic
switch
that
prevents
the
burner from starting,
or
stops the burner from
firing
if
the selected fuel oil temperature
is
lower
than is required for proper oil burner operation.
(15) High
Oil Temperature
Switch
(Not
Shown)
(Optional):
The
switch contacts
open
when the
fuel
oil
temperature
rises
above
a
selected
temperature.
The
switch will interrupt the limit
circuit in the event the fuel oil temperature rises
above the selected point.
·
(16) In addition to the components
of
the fuel oil
controller mentioned in Section
H, the following
are used with a heavy oil fired burner.
(a)Fuel
Oil Thermometer: Indicates the
temperature
of
fuel oil being supplied to
the fuel oil controller.
(b)Back
Pressure· Valve:
For
the adjust-
ment
of
the
oil
pressure
on
the
downstream
side
of
the metering valve.
Also regulates the rate
of
return oil flow.
(c)Oil Return Pressure Gauge: Indicates
the oil pressure
on
the return side
of
the
fuel oil controller.
750-150
(d)Manual By-Pass Valve: Provided as a
time
saver
in establishing oil flow.
When
operi, it permits the circulation
of
oil
through
the
supply
and
return
l-ines.
During
operation, this
valve
1IlJ.W.
be
closed.
(e)Orifice
Oil Control Valve:
The
valve
may
be
opened prior to
start·up
to aid in
establishing fuel oil flow through the
controller. Prior
to
the initial light off, this
valve
~
be
closed. Its disc has an
orifice to permit a continuous circulation
of
hot fuel oil through the controller.
(17)
Air
Purge Valve (Not Shown):
The
solenoid
valve
opens
simultaneously with the closing
of
the oil solenoid valve at burner shutdown, allow-
ing compressed air
to purge oil from the burner
nozzle and adjacent piping.
This
oil
is
burned by
the diminishing flame, which continues burning
for approximately 4 seconds after the oil solenoid
valve closes.
(18)
Air Purge Orifice Nozzle (Not Shown):
Limits purging air
to
the proper quantity for
expelling unburned oil at normal delivery rate.
(19)
Air
Purge
Orifice
Nozzle
Filter·
(Not
Shown): Filters the purging air
of
any particles
that
might
plug the air purge orifice nozzle.
(20)
Air
Purge
Check
Valve (Not Shown):
The
check valve prevents the fuel oil from entering
the atomizing air line.
(21)
Air
Purge
Relay (Fig. 1-7):
When
energized,
controls operation
of
the air purge valve.
CHAPTER 1-15
To Next Page
Loading...