Table of Contents
Advertisement
F.
If boiler is used in connection with refrigeration
systems, boiler must be installed with chilled medium
piped in parallel with the heating boiler using
appropriate valves to prevent chilled medium from
entering boiler. See Figure 4. Also consult I=B=R
Installation and Piping Guides.
G.
If boiler is connected to heating coils located in air
handling units where they may be exposed to
refrigerated air, boiler piping must be equipped with flow
control valves to prevent gravity circulation of boiler
water during operation of cooling system.
H.
Use a boiler bypass if the boiler is to be operated in a
system which has a large volume or excessive radiation
where low boiler water temperatures may be
encountered (i.e. converted gravity circulation system,
etc.).
Figure 4: Recommended Piping for Combination Heating & Cooling (Refrigeration) Systems
IV. Gas Piping
A.
Size gas piping. Design system to provide adequate
gas supply to boiler. Consider these factors:
1. Allowable pressure drop from point of delivery to
boiler. Maximum allowable system pressure is ½
psig. Actual point of delivery pressure may be less;
contact gas supplier for additional information.
Minimum gas valve inlet pressure is listed on
rating label.
2. Maximum gas demand. Table 2 lists boiler input
rate. Also consider existing and expected future gas
utilization equipment (i.e. water heater, cooking
equipment).
3. Length of piping and number of fittings. Refer to
Table 3 for maximum capacity of Schedule 40 pipe.
Table 4 lists equivalent pipe length for standard
fittings.
Remove circulator and install pipe tee between circulator
and boiler return along with second tee in supply piping
as shown in Figure 3. Bypass should be same size as
the supply and return lines with valves located in
bypass and supply outlet as illustrated in Figure 3 in
order to regulate water flow to maintain higher boiler
water temperatures.
Set by-pass and boiler supply valves to half throttle
position to start. Operate boiler until system water
temperature reaches normal operating range.
Adjust valves to provide 180° to 200°F supply water
temperature. Opening the boiler supply valve will raise
system temperature, while opening by-pass valve will
lower system supply temperature.
I.
A hot water boiler installed above radiation level must
be provided with a low water cutoff device as part of
installation.
Table 2: Rated Input
B
o
l i
r e
c [
u
b
M
o
d
l e
N
u
m
b
r e
N
t a
r u
l a
3
0
6
2
4
0
9
6
5
0
1
3
6
0
1
6
7
0
1
9
8
0
2
3
2
6
n I
p
t u
R
a
e t
c i
e f
t e
p
r e
h
o
u
] r
C
G
a
s
L
P
P /
o r
p
a
n
e
2
4
¾
3
8
½
0
5
2
4
6
5
½
8
7
9
¼
9
2
¾
G
a
s
o
n
n
e
t c
o i
n
i S
e z
½
½
½
½
¾
¾
Hide quick links:
Advertisement
Table of Contents
