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VISCOSITY: The HTF viscosity over the service temperature range is based on a specific gravity 15/15
o
C
(60/60
o
F) 1.053-1.063. DOWFROST inhibited glycol-based fluid has an effective operating temperature
range of -50
o
F to 250
o
F. At temperatures below -50
o
F, increased viscosity (>1,000 centipoise) can make
use of DOWFROST impractical unless larger pumps are installed. At the upper end of the operating
range for DOWFROST fluid, a maximum bulk temperature of 250
o
F is recommended. Film temperature
should not exceed 300
o
F. DOWFROST fluid can tolerate brief temperature excursions up to 100
o
F above
the maximum recommended temperatures. However, extended exposure of the fluid to temperatures in
excess of 50
o
F above the maximum recommended temperatures will result in accelerated degradation of
the glycol and inhibitor systems. In addition, the film temperature should remain within 50
o
F of the bulk
fluid temperature and the pressure at all points in the system should be at least 5 psi greater than the
vapor pressure exerted by the fluid to avoid localized boiling and resulting precipitation. At temperatures
above 150
o
F, the system must be closed to avoid rapid oxidation of the propylene glycol, inhibitor
depletion, and subsequent increased corrosion. Automatic make-up water systems should be avoided in
order to prevent undetected dilution or loss of glycol and consequent loss of freeze and corrosion
protection.
FLAMMABILITY: When mixed with water, DOWFROST is not flammable, as the fluid has no measurable
flash point (Pensky-Martens Closed Cup) in concentrations up to 80% glycol. Undiluted DOWFROST has
a flash point of 214
o
F (Pensky-Martens Closed Cup). It is possible to ignite solutions of propylene if
enough water has been vaporized and the concentration of propylene glycol increases to greater than 80
percent.
INSPECTION AND TREATMENT OF HEAT TRANSFER FLUID: You can quickly determine the
condition of your fluid by examining its appearance and odor. Any drastic variation from the initial fluid
specifications, such as a black or dark-grey color, presence of an oily layer, burnt odor, or any heavy
sludge in the fluid may indicate the need for replacement.
TESTING THE FLUID pH LEVEL: Control of pH between 8 and 10 is important to minimize corrosion and
glycol degradation. Using narrow range pH paper, such as pHydrion Control paper with a 7.2 to 8.8 pH
range, is an easy and reliable way to read your pH level. A pH tester can also measure alkalinity or acidity
and give you an indication of the reserve alkalinity or inhibitor level of the fluid. The desirable pH range
should fall between 8.0 and 10.0. Adjustments can be made using a 50% solution of sodium hydroxide or
potassium hydroxide if the pH is approaching the acidic range (below 8.0). An inexpensive pH tester is
available from Misco Products. The accuracy of this product is +/- 0.5 pH. Contact Misco Products at 1-
800-358-1100 and ask for the Dow discount.
SPILL, LEAK, AND DISPOSAL PROCEDURES: Using appropriate safety equipment, small spills may
be soaked up with common absorbent material. For large spills, the fluid should be pumped into suitable
containers located in diked areas. Residual material should be cleaned up with water. Concentrate can be
handled according to local, state, and federal regulations.
EMERGENCY OVERVIEW
POTENTIAL HEALTH EFFECTS
EYE: May cause slight transient (temporary) eye irritation.
Corneal injury is unlikely. Mists may cause eye irritation.
FIRST AID: FLUSH EYES WITH PLENTY OF WATER
SKIN CONTACT: Prolonged contact is essentially non-irritating to skin. A single prolonged exposure is
not likely to result in the material being absorbed through the skin in harmful amounts. Repeated
exposure may cause flaking and softening of skin.
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