7
Table 2 — Water Quality Guidelines
*If the concentration of these corrosives exceeds the maximum allow-
able level, then the potential for serious corrosion problems exists.
†Sulfides in the water quickly oxidize when exposed to air, requiring that
no agitation occur as the sample is taken. Unless tested immediately at
the site, the sample will require stabilization with a few drops of one
Molar zinc acetate solution, allowing accurate sulfide determination up
to 24 hours after sampling. A low pH and high alkalinity cause system
problems, even when both values are within ranges shown. The term
pH refers to the acidity, basicity, or neutrality of the water supply. Below
7.0, the water is considered to be acidic. Above 7.0, water is considered
to be basic. Neutral water contains a pH of 7.0.
NOTE: To convert ppm to grains per gallon, divide by 17. Hardness in
mg/l is equivalent to ppm.
CONDITION
ACCEPTABLE LEVEL
pH
7 to 9 range for copper. Cupro-nickel may be used in the 5 to 9 range.
Total Hardness
Calcium and magnesium carbonate should not exceed 20 grains per gallon (350 ppm).
Iron Oxides
Less than 1 ppm.
Iron Bacteria
No level allowable.
Corrosion*
Max Allowable
Level
Coaxial
Metal
Ammonia, Ammonium Hydroxide
0.5 ppm
Cu
Ammonium Chloride, Ammonium Nitrate
0.5 ppm
Cu
Ammonium Sulfate
0.5 ppm
Cu
Chlorine/Chlorides
0.5 ppm
CuNi
Hydrogen Sulfide†
None Allowable
—
Brackish
Use Cupro-nickel heat exchanger when concentrations of calcium or sodium chloride are greater than 125 ppm
are present. (Seawater is approximately 25,000 ppm.)
Ball Valve with
integral P/T plug
Ball Valve with
integral P/T plug
Load Heat Exchanger
Connection
Air Pad or
Extruded
polystyrene
insulation board
Concrete
block or
brick
Unit Power
Disconnect
Y-Strainer
with blow-off
valve
Water In
Water Out
Thermostat
Wiring
Building
Loop
Stainless steel
braided hose
Automatic
Balancing
Valve
Optional Low
Pressure Drop
Solenoid
Valve
Fig. 2A — Typical Water Loop (Boiler/Tower) System (50RWS036-120 Units Shown)