Jetson FWCD Series, Installation Operation & Maintenance, Page: 95 / 96

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Appendix B
Piping System Flushing Procedure
Prior to connecting the chiller to the condenser and
chilled water loop, the piping loops shall be
flushed with a detergent and hot water (110-
130°F) mixture to remove previously accumulated
dirt and other organics. In old piping systems with
heavy encrustation of inorganic materials consult
a water treatment specialist for proper passivation
and/or removal of these contaminants.
During the flushing, 30 mesh (max.) Y-strainers
(or acceptable equivalent) shall be in place in the
system piping and examined periodically as
necessary to remove collected residue. The use of
on-board chiller strainers shall not be acceptable.
The flushing process shall take no less than 6
hours or until the strainers when examined after
each flushing are clean. Old systems with heavy
encrustation shall be flushed for a minimum of 24
hours and may take as long as 48 hours before the
filters
run clean. Detergent and acid
concentrations shall be used in strict accordance
with the respective chemical manufacturer's
instructions. After flushing with the detergent
and/or dilute acid concentrations the system loop
shall be purged with clean water for at least one
(1) hour to ensure that all residual cleaning
chemicals have been flushed out.
Prior to supplying water to the chiller, the Water
Treatment Specification shall be consulted for
requirements regarding the water quality during
chiller
operation. The appropriate chiller
manufacturer's service literature shall be available
to the operator and/or service contractor and
consulted for guidelines concerning preventative
maintenance and off-season shutdown procedures.
Water Treatment Requirements
Supply water for both the chilled water and
condenser water circuits shall be analyzed and
treated by a professional water treatment specialist
who is familiar with the operating conditions and
materials of construction specified for the chiller's
heat exchangers, headers and associated piping.
Cycles of concentration shall be controlled such
that recirculated water quality for compact chillers
using 316 stainless steel brazed plate heat
exchangers and carbon steel headers is maintained
within the following parameters.
Figure 37. Water property limits
Water Property Concentration Limits
Alkalinity (HCO
3
-
) 70-300 ppm
Sulfate (SO
4
2-
) Less than 70 ppm
HCO3- / SO42- Greater than 1.0
Electrical Conductivity 10 - 500 μS/cm
pH 7.5 – 9.0
Ammonia (NH3) Less than 2 ppm
Chlorides (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 (CO2)
Less than 5 ppm
Total Hardness (°dH) 4.0 - 8.5
Nitrate (NO3) 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