Install Instructions
CG i
GAS-FIRED
wATER
BOILER-
sERIEs
a-
Boiler
Manual
4b
Water
piping
-
single-zone
system
I
AcAunoN
I
Undersized expansion tanks cause
syste
m water to be lost
from
re
li
ef
valve
and makeup water
to be added through
till
valve.
Eve
ntual section failure can result
Diaphragm-type
or
bladder-
type
expansion
tank
(Figure
16)
t.
Ensure expansion tank size will handle
oo
il
er and
system
wate
r volume a
nd
temperature. Tank must
be located
in
boiler return piping as close to
oo
il
er
as
possible, before inlet side of circulator.
See
tank
ma
nu
facturer's instructions for details.
2.
In
stall an automatic air
vent
as
shown.
Closed-type
expansion
tank
(Figure
17)
t. Ensure expansion tank size
will
handle ooiler and
system
wa
ter
vo
lume and temperatur
e.
See
tank
manu
facturer•s instructions for details.
2. Co
nn
ect tank to 'h''
NPT
tapping located behind
supply outlet, using
'h"
NPT
pipin
g.
Pitch any
horizontal piping up towards tank
I inch per 5
feet
of
piping.
I&
WARNING!
Use
Figure
16
or Ftgure
17
only for single-zone systems designed for return
wate
r
at
least I 30°F.
For systems with
low
return
wate
r temperature possible, such
as
converted gravity systems
and
radiant heating systems, refer to the special piping suggestions
of
pages
24-29.
Failu
re to
prevent
low
return water temperature to the ooiler could cause corrosion
of
the ooiler sections
or
burners, resulting in severe personal injur
y,
death or substanti
al
property damage.
Figure 16 Diaphragm- or bladder-type expansion
ta
nk -
Pi
pi
ng
to s
in
gle-zone system
using diaphragm-type or bladder-type
expansion tank.
See
Tab
le 6 for piping
sizes.
Isolation
valve
Circulator
From
system
Cold
water
fill
To
DIAPHRAGM
expansion
tank
and fittings
To
system
Automatic
air
vent
•Alternate
location
Figure 17 Closed-type expansion tank -
Piping
to si
ngle
-zone system us
in
g closed-
type expans
io
n tank.
See
Table 6
for
piping sizes.
Relief
valve
Circulator
From
system
CLOSED
type
expansion
tank
--.......
~.....-
Isolation
valve
To
system
•Alternate
locat
ion
Part Number 550-142-780/0712 21