Rapid 7500 136 Installation, operation & service manual - page 123
SECTION 16: S
TART
-
UP
P
ROCEDURES
111 of 143
bu
rner to determine specific nozzle press
u
res and
firing rates.
At light off, the main oil solenoid
v
al
v
es are
energized, allo
w
ing f
u
el to the nozzle. A normally
open p
u
mp mo
u
nted oil solenoid
v
al
v
e allo
w
s a
controlled flo
w
of oil to the nozzle in accordance
w
ith
the press
u
re setting of the p
u
mp lo
w
fire adj
u
stment.
When the lo
w
fire flame is pro
v
en
b
y the flame
detector, the p
u
mp-mo
u
nted, normally open solenoid
v
al
v
e is energized (closes), p
u
tting f
u
ll high fire p
u
mp
press
u
re on the nozzle. Sim
u
ltaneo
u
sly, the three-
w
ay solenoid
v
al
v
e is energized, allo
w
ing oil into the
hydra
u
lic oil cylinder
w
hich mechanically dri
v
es the
air damper arm to the high fire open position. The
bu
rner operates at f
u
ll high fire
u
ntil the system
demand is satisfied.
FIGURE 91: Oil Pressure Adjustment Hi
g
h/Low/
Off Burner with Suntec Pump
16.
8
.3 Oil Pressure Adjustments for Hi
g
h/Low/Off
Burner with Webster Pump
This high/lo
w
/off system
u
ses a t
w
o-stage oil p
u
mp
w
ith a simplex oil nozzle or an internal
b
ypass nozzle
in conj
u
nction
w
ith mo
v
a
b
le com
bu
stion air dampers
to pro
v
ide a lo
w
fire start and a high fire r
u
n
seq
u
ence. Nozzle s
u
pply press
u
re is set
b
y adj
u
sting
the oil p
u
mp press
u
re reg
u
lator. T
u
rn clock
w
ise to
increase the press
u
re and co
u
nter-clock
w
ise to
decrease the press
u
re to the nozzle.
Nozzle s
u
pply press
u
re is taken at the pl
u
gged p
u
mp
nozzle press
u
re ga
u
ge port. Nozzle s
u
pply press
u
re
w
ill normally
b
e approximately 300 PSI (20684 m
b
ar)
at
b
oth high and lo
w
firing rates. Flo
w
rate press
u
re
for
b
oth high and lo
w
fire is taken at
b
ypass press
u
re
ga
u
ge tee. Lo
w
fire press
u
res are set
b
y adj
u
sting the
lo
w
fire reg
u
lating
v
al
v
e. T
u
rning the lo
w
fire
reg
u
lating
v
al
v
e adj
u
stment n
u
t clock
w
ise
w
ill
increase the press
u
re at the
b
ypass press
u
re test tee
ga
u
ge (increasing the lo
w
fire inp
u
t) and co
u
nter
clock
w
ise
w
ill red
u
ce the press
u
re at the ga
u
ge
(decreasing the lo
w
fire inp
u
t). Lo
w
fire ret
u
rn
press
u
re
w
ill normally
b
e in 60 to 100 PSI (4135 -
6894 m
b
ar) range and at high fire in the 180 to 225
PSI (12410 - 15513 m
b
ar) range,
bu
t
b
oth press
u
res
w
ill
v
ary according to the specific nozzle
b
eing
u
sed,
as
w
ell as jo
b
conditions.
At light-off, the main oil solenoid
v
al
v
e is energized,
allo
w
ing f
u
el to flo
w
to the nozzle. At the same instant
a portion of the oil
b
ypasses the nozzle thro
u
gh the
adj
u
sta
b
le lo
w
fire reg
u
lating
v
al
v
e, red
u
cing the
press
u
re at the nozzle as req
u
ired for lo
w
fire rates.
When the lo
w
fire flame is pro
v
en
b
y the flame
detector, the ret
u
rn oil solenoid
v
al
v
e is de-
energized, p
u
tting f
u
ll high fire p
u
mp press
u
re on the
nozzle. Sim
u
ltaneo
u
sly, the three-
w
ay solenoid
v
al
v
e
is energized, allo
w
ing oil into the hydra
u
lic cylinder
w
hich mechanically dri
v
es the air damper arm to the
high fire position. The
bu
rner operates at f
u
ll high fire
u
ntil the system demand is satisfied. Refer to the
bu
rner's man
u
fact
u
rer's man
u
al packed
w
ith the
bu
rner to determine specific nozzle press
u
res and
firing rates.
NOTE:
Some high/lo
w
/off
w
ill
b
e s
u
pplied
w
ith
simplex, rather than internal
b
ypass type, oil nozzles.
The mechanical operation of the simplex nozzle
system is essentially the same as the internal
b
ypass
system - except that lo
w
fire oil press
u
res sho
u
ld
b
e
set at 100 to 125 psig (6894 - 8618 m
b
ar) (adj
u
st to
s
u
it jo
b
conditions) and high fire oil press
u
res at 280
to 300 psig (19305 - 20684 m
b
ar) at the oil p
u
mp
nozzle press
u
re ga
u
ge test port. Refer to the
bu
rner's
man
u
fact
u
rer's man
u
al packed
w
ith the
bu
rner to
determine specific nozzle press
u
res and firing rates.
FIGURE 92: Oil Pressure Adjustments for Hi
g
h/
Low/Off Burner with Webster Pump
16.
8
.4 Oil Pressure Adjustments for Fully-Modu-
latin
g
Burner with Webster Pump
The f
u
ll mod
u
lating system
u
ses a t
w
o-stage oil
p
u
mp
w
ith an internal
b
ypass type oil nozzle. A
mod
u
lating act
u
ator controls the positioning of the