Installation & Operation Manual
5 Hydronic piping (continued)
It is required that boiler piping systems
utilize Primary/Secondary or Fixed or
Variable Flow Primary configurations as
shown in FIG.’s 5-2 thru 5-5. The use of
other boiler piping configurations could
result in improper building and system flow
rates leading to inadvertent boiler high limit
shutdowns and poor system performance.
NOTICE
The pressure drop reflected in FIG. 5-1 is
for the boiler only. Additional allowances
must be made for piping, especially if
sizing pumps for Primary/Secondary
applications.
NOTICE
TEMPERATURE RISE APPLICATIONS
Model BOILER
CONNECTION SIZE
20°F 40°F 60°F
GPM FT/HD GPM FT/HD GPM FT/HD
FB 1500 4" 138 3.4 69 1.5 46 1.0
FB 2000 4" 184 4.1 92 1.6 61 1.0
FB 2500 4" 230 4.6 115 1.3 77 0.7
FB 3000 4" 277 5.6 138 1.2 92 0.7
FB 3500 4" 323 7.5 161 1.2 108 0.7
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
0 50 100 150 200 250 300 350
FBN1500
FBN2000
FBN2500
FBN3000
FBN3500
Flow Rate (GPM)
Pressure Drop (Feet of Head)
CREST Pressure Drop Curve
Figure 5-1 Pressure Drop vs. Flow
Table 5A Sizing Information for Temperature Rise Applications_20°F, 40°F and 60°F
25
Circulator sizing
The Crest heat exchanger does have a pressure drop, which must be considered in your system design. Refer to the graph in
FIG. 5-1 for pressure drop through the Crest heat exchanger.
[Based on 92% AHRI Effi ciency]