18-CG03D1-4
17
4-W
a
y
Mot
o
riz
e
d
V
alv
e
Boiler
Back
F
lo
w
P
rev
ent
e
r
Globe
V
a
lv
e
Globe
V
alv
e
Globe
V
alv
e
P
ressur
e
Reduc
e
r
P
ressur
e
G
auge
Air
S
epar
at
or
Expansion
Tank
T
ypical
S
yst
e
m
P
iping
Diagr
a
m
P
rimar
y
S
e
condar
y
L
oop
with
4-wa
y
Mot
o
riz
e
d
V
alv
e
with
Cir
culat
ors
in
P
rimar
y
and
S
e
condar
y
L
oops
L
o
w
Temper
arur
e
w
ith
L
o
w
M
ass
H
eat
Emitt
ers
or
High
Temper
atur
e
w
ith
High
or
L
o
w
M
ass
Heat
Emitt
ers
Cir
culat
o
r
Pu
m
p
Circulator
Pu
m
p
Return
W
at
er
Te
mper
atur
e
S
ensor
Supply
W
a
te
r
Te
mper
atur
e
S
e
nsor
Return
w
at
er
te
mper
atur
e
m
u
stb
ea
b
o
v
e
1
1
0
O
F
Heat
Emitt
er
2
1
2
1
3
3
NO
TES:
P
rot
ec
ts
boiler
fr
om
to
o
lo
w
return
w
at
er
temper
atur
e
and
condensation.
L
o
cat
e
the
cir
culat
o
r
inlet
close
to
the
connec
tion
point
o
f
the
expansion
tank,
but
allo
w
a
t
least
the
equiv
a
lent
of
10
to
12
pipe
diamet
ers
betw
een
the
cir
culat
or
pump
inlet
a
nd
the
expansion
tank
to
re
duc
e
the
possibilit
y
of
pump
noise
and
facilitat
e
air
remo
v
a
l.
Close
co
upled
Tees
Return
Supply
Relief
V
alv
e
Exhaust
Ve
n
t
