18
R
D
H
R
D
H
L
E
D
O
M
SIZE
GPM
T
P FT
GPM
T
P FT CONN
GPM
T
P FT
GPM
T
P FT CONN
133*
22
10
14.7
10
22
3.3
1-1/4"
182/
181
45
7
9.2
20
15
1.8
1-1/2"
260/
261
45
10
9.4
20
22
1.9
1-1/2"
330/
331
45
12
9.6
20
28
1.9
1-1/2"
400/
401
45
15
9.8
20
33
2.0
1-1/2"
514
90
9
9
40
21
1.8
2"
624
90
12
9.5
40
26
1.9
2"
724
90
13
10
40
30
2.0
2"
824
90
15
10.5
40
34
2.1
2"
926
90
17
11
40
38
2.2
2 1/2"
200
8
9.7
90
17
2.1
3"
962
90
18
11
40
40
2.2
2 1/2"
200
8
9.7
90
18
2.1
3"
1083
90
20
12
45
40
3.1
2 1/2"
200
9
10.3
90
20
2.3
3"
1125
90
21
12
47
40
3.3
2 1/2"
200
9
10.3
90
20
2.3
3"
1178
90
22
12.5
49
40
3.8
2 1/2"
200
10
11
90
21
2.4
3"
1223
90
22
12.5
51
40
4.0
2 1/2"
200
10
11
90
22
2.4
3"
1287
90
24
13.2
53
40
4.5
2 1/2"
200
11
11.7
90
23
2.5
3"
1336
90
24
13.2
55
40
4.9
2 1/2"
200
11
11.7
90
24
2.5
3"
1414
90
26
14
58
40
5.8
2 1/2"
200
12
12.2
90
26
2.7
3"
1468
90
27
14
61
40
6.4
2 1/2"
200
12
12.2
90
27
2.7
3"
1571
90
29
14.5
65
40
7.5
2 1/2"
200
13
13
90
29
2.8
3"
1631
90
30
14.5
68
40
8.3
2 1/2"
200
13
13
90
30
2.8
3"
1758
90
32
15.4
73
40
10.0
2 1/2"
200
14
14.7
90
32
3
3"
1826
90
34
15.4
76
40
10.8
2 1/2"
200
15
14.7
90
33
3
3"
2100
200
17
14.8
90
39
3.2
3"
400
9
18
180
19
4
4"
2500
200
21
15.8
103
40
4.4
3"
400
10
18.8
180
23
4.1
4"
3001
200
25
16.7
124
40
6.7
3"
400
12
19.5
180
27
4.3
4"
3500
200
29
17.5
145
40
9.5
3"
400
14
20.5
180
32
4.5
4"
4001
200
33
18.7
166
40
13.0
3"
400
16
21.5
180
36
4.7
4"
MAXIMUM AND MINIMUM FLOW RATES
2-PASS HEAT EXCANGER
1-PASS HEAT EXCHANGER
N
I
M
X
A
M
N
I
M
X
A
M
GPM Flow rates limited by maximum acceptable velocity through heat exchanger tubes. May be increased by 10% for closed heating
systems.
* 4 Pass Heat Exchanger
BOLD TYPE
indicates Low NOx models.
difference between the inlet and outlet water when the
boiler is firing at full rate). For some boilers, the Delta
T is more than 20°F (22°-33°F) at the recommended
flow rates.
Feedwater Regulator
We recommend that a feedwater regulator be installed
and set at 12 PSIG minimum pressure. Install a check
valve or back flow device upstream of the regulator,
with a manual shut-off valve. Leave the valve open.
Piping—Heating Boilers
We recommend that all high points be vented and that
purge valves and a bypass valve be installed. A boiler
installed above radiation level must be provided with a
low water cut-off device. The boiler, when used in con-
junction with a refrigeration system, must be installed
so that the chilled medium is piped in parallel with the
boiler with appropriate valves to prevent the chilled
medium from entering the boiler.
Recommended Purge Manifolds for
Typical Hydronic System Hookups
The boiler piping system of a hot water heating boiler
connected to heating coils located in air handling units
where they may be exposed to refrigerated air circulat-
ing, must be equipped with flow control valves or other
automatic means to prevent gravity circulation of the
boiler water during the cooling cycle.
Temperature & Pressure Gauge
The temperature & pressure gauge is standard equip-
ment on all hydronic heating and hot water supply
boilers. All temperature & pressure gauges are factory
mounted in the in/out header except for residential
boilers, Models 133 and 181-401. On these models
the temperature & pressure gauge is shipped loose for
field installation, and located in the outlet water con-
nection. All fittings required to mount gauge to piping
system are supplied by others.
Table H: Maximum and Minimum Flow Rates