AERCO Modulex EXT 321 - 1123 - Manual (Page 41)

MODULEX EXT 321, 481, 641, 802, 962, 1123 BOILERS
Installation, Operation & Maintenance Manual
Table 3-2: MODULEX EXT Minimum/Maximum Flow Rates
Boiler Model 321 481 641 802 962 1123
Min. flow rate demanded in gal/min
∆T 27°F (15°C)
2.5 2.5 2.5 2.5 2.5 2.5
Min. flow rate demanded in gal/min
∆T 36°F (20°C)
1.9 1.9 1.9 1.9 1.9 1.9
Max flow rate demanded in gal/min
∆T 27°F (15°C)
24.5 36.8 49.2 61.7 74.2 86.8
Max flow rate demanded in gal/min
∆T 36°F (20°C)
18.4 27.6 36.9 46.3 55.6 65.1
The water side resistance curve of the boiler is shown in the diagram in Figure 3-18.
The pump is not an integral part of the boiler. It is recommended to choose a pump with the rate
and delivery head at about 2/3 of its characteristic heating curve.
Figure 3-18: MODULEX EXT Water Side Pressure Losses
NOTE
The use of a mixing header fitted between the boiler circuit and the
system circuit is always advisable. It becomes INDISPENSABLE if
the system requires flow rates superior to the maximum permitted
boiler flow rates, which is to say lower than 27° F (15 K).
OMM-0087_0E AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 Page 41 of 148
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