40
Water system cleaning
Proper water system cleaning is of vital importance. Exces-
sive particulates in the water system can cause excessive
pump seal wear, reduce or stop flow, and cause damage of
other components. Water quality should be maintained
within the limits indicated in the Water Quality Characteris-
tics and Limitations Table.
1. Install a temporary bypass around the chiller to avoid
circulating dirty water and particulates into the pump
package and chiller during the flush. Use a temporary
circulating pump during the cleaning process. Also,
be sure that there is capability to fully drain the sys-
tem after cleaning.
2. Be sure to use a cleaning agent that is compatible
with all system materials. Be especially careful if the
system contains any galvanized or aluminum compo-
nents. Both detergent-dispersant and alkaline-dispers-
ant cleaning agents are available.
3. It is a good idea to fill the system through a water
meter. This provides a reference point for the future
for loop volume readings, but it also establishes the
correct quantity of cleaner needed in order to get the
required concentration.
4. Use a feeder/transfer pump to mix the solution and
fill the system. Circulate the cleaning system for the
length of time recommended by the cleaning agent
manufacturer.
a. After cleaning, drain the cleaning fluid and flush
the system with fresh water.
b. A slight amount of cleaning residue in the system
can help keep the desired, slightly alkaline, water
pH of 8 to 9. Avoid a pH greater than 10, since
this will adversely affect pump seal components.
c. A side stream filter is recommended during the
cleaning process. Filter side flow rate should be
enough to filter the entire water volume every 3 to
4 hours. Change filters as often as necessary dur-
ing the cleaning process.
d. Remove temporary bypass when cleaning is
complete.
A strainer with a blow-down valve is standard on all 30RA
units, both with and without hydronic packages. The blow-
down valve allows removal of particulates caught in the
strainer without complete removal of the screen. A female
NPT connection is provided on the valve, allowing hose
connection for drainage outside the unit.
The
Comfort
Link™ controls provided have a built-in fea-
ture to remind building owners or operators to clean the
strainer by discharging the blow-down valve at a pre-set
time interval. Properly installed and cleaned systems will
rarely need the strainer cleaned after the initial fill. This
time interval is user-configurable.
WATER QUALITY CHARACTERISTICS
AND LIMITATIONS
*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 sta
b
ilization 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 pro
b
-
lems, even when
b
oth values are within the ranges shown. The term pH
refers to the acidity,
b
asicity, or neutrality of the water supply. Below 7.0,
the water is considered to
b
e acidic. A
b
ove 7.0, water is considered to
b
e
b
asic. Neutral water contains a pH of 7.0.
†Dissolved car
b
on dioxide can either
b
e calculated from the pH and total
alkalinity values, shown
b
elow, or measured on the site using a test kit.
Dissolved Car
b
on Dioxide, PPM = TA x 2
[(6.3-pH)/0.3]
where TA = Total Alka-
linity, PPM as CaCO
3
.
5
6
7
1
2
4
3
LEGEND
1
—
Strainer
2
—
Blow-Down Valve
3
—
Discharge Check Valve
(Dual Pumps Only)
4
—
Balancing Valve with Drain Plug
5
—
Flow Switch
6
—
Field Connections
7
—
Heater
TYPICAL DUAL PUMP PACKAGE
WATER CHARACTERISTIC
QUALITY LIMITATION
Alkalinity (HCO
3
-
)
70 – 300 ppm
Sulfate (SO
4
2-
)
Less than 70 ppm
HCO
3
-
/SO
4
2-
Greater than 1.0
Electrical Conductivity
10 – 500
μ
S/cm
pH
7.5 – 9.0
Ammonium (NH
3
)
Less than 2 ppm
Chorides (Cl
-
)
Less than 300 ppm
Free chlorine (Cl
2
)
Less than 1 ppm
Hydrogen Sulfide (H
2
S)*
Less than 0.05 ppm
Free (aggressive) Carbon
Dioxide (CO
2
)†
Less than 5 ppm
Total Hardness (dH)
4.0 – 8.5
Nitrate (NO
3
)
Less than 100 ppm
Iron (Fe)
Less than 0.2 ppm
Aluminum (Al)
Less than 0.2 ppm
Manganese (Mn)
Less than 0.1 ppm
Application data (cont)