Industrial Water Engineering, Inc.

CHEMICAL WATER TREATMENT

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GSA # GS-10F-7884A (1/31/2007)

DOD Cage # 0MV90

 

 

Hot water boilers and cold water closed loops are termed "closed loop" systems. These systems are similar to a car radiator, in that once they are filled with water additional makeup water is minimal. Water is not intentionally removed via blowdown from either system. The systems are essentially open to atmosphere and are treated like oxygenated systems.

Three types of treatment are currently available to treat closed loops. The most common is a nitrate/borate type such as CS-4015. Nitrite/borate systems are typically maintained in the 400 to 800 mg/L nitrite range. Another treatment is Nitrite/molybdate such as CS-4694. Nitrite/Molybdates are typically maintained at the 80 to 120 mg/L range. Yet another treatment is the CS-4690 that is an organophosphate type treatment.

Microbiocides may be needed in certain instances.  Microbiocides recommended are IWE-7420 and AQ-7423. All formulations listed above are compatible with glycol. Propylene glycol is recommended when freeze protection is needed. Propylene glycol is not poisonous like its cousin ethylene glycol.

Under no circumstances, should sodium sulfite be added to closed loops. Sulfite consumption will reach the point where the sulfate and chloride residuals are so high that corrosion of metal will occur. Closed loops are oxygenated and trying to use sulfite to remove the oxygen is an ignorant and poor choice.