J. check/control water chemistry – HTP EFT-399 User Manual
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LP-387 REV. 6.10.14
The chart below represents the various system design temperature rise through the boiler along with their respective flows and friction
loss, which will aid in circulator selection.
In addition, the heat exchanger has a minimum total water volume that must be taken into account when sizing the circulator. These
minimum water volumes are listed in Table 6 below.
MINIMUM BOILER FLOW RATES
MODEL
MINIMUM FLOW RATE (GPM)
EFT-55
3.5
EFT-80
5.4
EFT-110
7
EFT-155
9.7
EFT-199
12.5
EFT-299
17.9
EFT-399
25
Table 6
– Minimum Heat Exchanger Water Volumes
The chart below represents the combined flow rates and pipe sizes when using multiple boilers to design the manifold system for the
primary circuit. To size, simply add up the number of boilers and the required flow rates for the system design temperature.
Example: (5) EFT-55 boilers with a design of 20°
Δt degree temperature rise with each boiler having an individual flow rate of 5.3 GPM.
To correctly size the manifold feeding these (5) boilers you would need a pipe size of 2
”.
MULTIPLE BOILER MANIFOLD PIPING
Maximum Flow Rate
(GPM at 3 feet per second)
8
14
19
31.5
45
69
93
120
150
188
271
Schedule 40 Pipe Diameter (Inches)
1
1¼
1½
2
2½
3
3½
4
4½
5
6
Table 7
J. CHECK/CONTROL WATER CHEMISTRY
NOTE: BOILER FAILURE DUE TO IMPROPER WATER CHEMISTRY IS NOT COVERED BY WARRANTY.
Sodium less than 20 mGL
Water pH between 6 and 8
1. Maintain boiler water pH between 6 and 8. Check with litmus paper or have chemically analyzed by water treatment company.
2. If pH differs from above, consult local water treatment company for treatment needed.
Hardness less than 7 grains
Consult local water treatment companies for unusually hard water areas (above 7 grains hardness).
Chlorine concentration less than 100 ppm
1. Filling with chlorinated fresh water should be acceptable since drinking water chlorine levels are typically less than 5 ppm.
2. Do not use the boiler to directly heat swimming pool or spa water.
3. Do not fill boiler or operate with water containing chlorine in excess of 100 ppm.
Table 5
– Boiler Flow Rates