M
A
X
IM
U
M
O
F
12
”O
R
4
P
IP
E
D
IA
M
E
TE
R
S
C
O
N
TR
O
LL
E
R
S
E
N
S
O
R
5’
M
A
X
LO
C
AT
E
B
U
FF
E
R
T
A
N
K
H
E
R
E
(I
F
R
E
Q
U
IR
E
D
)
Reverse return piping is a proper method of manifolding multiple boiler hook-ups to ensure balanced flow through each boiler. Valves on
supply and return are needed to isolate any boiler, as required.
Fig. 23: Multiple-Boiler– Reverse Return Hook-Up—Models 181–4001
19
