AM Series Boilers and Water Heaters
CHAPTER 4: INSTALLATION - PIPING
OMM-0100_0D
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, NY 10913
Page
41
of
154
GF-146
Ph.: 800-526-0288
03/28/16
The water heater pressure losses (see Figure 4-4) are based on potable water with a hardness
of 5 to 25 grains per gallon and a total dissolved solids not exceeding 200 ppm. Consult the
manufacturer when heating potable water exceeding these specifications.
Heating of high hardness and/or high total dissolved solids water increases the pressure drops
and may require a larger circulating pump, and a revised temperature rise specification based
on the water chemistry of the water to be heated.
Size your water system according to the following hardness guidelines to prevent scaling of the
heat exchanger. See Figure 4-4 for corresponding water flow.
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If the water is 5 to 8 grain per gallon, this is SOFT water and you have to size the system for
a 4 ft/sec minimum water velocity.
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If the water is 8 to 18 grain per gallon, this is NORMAL water and you have to size the
system for a 4 to 8 ft/sec minimum water velocity.
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If the water is 18 to 23 grain per gallon, this is HARD water and you have to size the system
for a 8 ft/sec minimum water velocity.
Figure 4-4: AM Series Water Velocity and Flow Graph
