Installation manual

Glycol Cooled/GLYCOOL™ Models

4.5 Preparation of Glycol Solutions

Typical ethylene glycol manufacturers and suppliers are Union Carbide (Ucartherm) or Dow Chemi-

cal Company (Dowtherm SR-1). These ethylene glycols are supplied with an inhibitor and do not con-

tain an anti-leak formula.

Commercial ethylene glycol, when pure, is generally less corrosive to the common metals of construc-

tion than water itself. Aqueous solutions of these glycols, however, assume the corrosivity of the

water from which they are prepared and may become increasingly corrosive with use if not properly

inhibited.

There are two basic types of corrosion inhibition; they are classified as corrosion inhibitors or environ-

mental stabilizers. The corrosion inhibitors function by forming a surface barrier that protects the

metals from attack. Environmental stabilizers, while not corrosion inhibitors in the strict sense of the

word, decrease corrosion by stabilizing or favorably altering the overall environment. An alkaline

buffer, such as borax, is a simple example, since its prime purpose is to maintain an alkaline condi-

tion (pH above 7).

The quality of the water used for dilution must be considered because water may contain corrosive

elements which reduce the effectiveness of the inhibited formulation. Preferably, surface water that is

classified as soft (low in chloride and sulfate ion content—less than 100 parts per million each) should

be used. Before an inhibited glycol solution is charged into a new or old system, residual contami-

nants such as sludge, rust, brine deposits, oil, etc., should be flushed out as completely as possible.

Avoid the use of strong acid cleaners. However, if they are required, inhibited acids should be consid-

ered. In any event, assure that the cleaning agent is completely removed before charging with glycol.

Contact Liebert Customer Service and Support for additional recommendations.

NOTE

For glycol solution preparation and periodic testing, follow manufacturer's

recommendations. Do not mix products of different manufacturers.

CAUTION

Automotive antifreeze is unacceptable and must NOT be used.

CAUTION

Galvanized pipe must not be used in glycol systems.

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