DOWTHERM SR-1 and DOWFROST HD Heat Transfer Fluids In ...

5. Circulate the system for at least
24 hours to ensure complete
mixing. Check the liquid concentration
with a refractometer or
other method to assure that the
correct mixture is obtained.
Note: If fluid mixing is a concern,
the solution can be premixed in a
separate tank before introduction
into the system, or the inhibited
glycol and the water can be added
together through a “mixing tee."
This will promote faster mixing of
the inhibited glycol and water.
6
MAINTAINING DOWTHERM AND DOWFROST FLUIDS
Free analytical service
To help ensure that corrosion and
freeze protection are maintained
in customer systems, Dow offers a
free fluid analysis service. It is
designed to assure the long term
performance of DOWTHERM
and DOWFROST fluids and help
minimize replacement fluid
requirements as well as system
maintenance and repair costs.
Typically performed on an annual
basis, the analysis includes determination
of current inhibitor and
glycol levels plus Dow’s recommendations
for maintaining
proper corrosion protection.
Dow has developed special Thermal
Fluids Sampling Kits for use
by customers participating in the
analysis program. These kits
permit easy and accurate labeling
of fluid samples and safe shipment
of samples to Dow for analysis.
Kits may be obtained by calling 1-
800-447-4369. Or write:
Thermal Fluids Testing Lab
The Dow Chemical Company
Larkin Lab
1691 North Swede Road
Midland, Michigan 48674
How the service works
After the system has been filled
and circulated for several days, an
initial four-ounce sample should
be withdrawn and sent to Dow
using one of the Thermal Fluids
Sampling Kits. After the system is
in operation, it is recommended
that samples be taken once a year.
Before withdrawing the sample,
the fluid should be well circulated
in the system so the sample is
representative. Remember to
closely follow the sampling
instructions included with the
sample kit provided by Dow.
Proper sampling is essential to
ensure meaningful assessment of
fluid condition.
Approximately three weeks after
the sample is received by Dow, a
report will be sent to you detailing
results of the analysis, discussing
unusual or troublesome conditions
(if any), and offering recommendations.
Analytical tools for selftesting
It may also be desirable to perform
some simple, on-site analysis of
your system to properly maintain
the glycol concentration. A useful
tool for this type of analysis is a
Misco Products refractometer,
model 7084VP (°F) and 7064VP
(°C). These refractometers
measure the glycol solution
concentration of DOWTHERM
and DOWFROST fluids and give
the freezing points of the fluids.
The freezing point can be translated
to glycol concentration from
the tables on pages 7 and 10. This
instrument requires only a few
drops of fluid for testing and
requires no adjustment for fluid
temperature. Diluted solutions
with concentrations from 0 to
60% glycol may be tested directly.
Stronger concentrations require a
simple dilution procedure prior to
testing. Contact Misco Products at
1-800-358-1100 and ask for the
Dow discount.