Hypertherm HT4400 HySpeed Plasma Arc Cutting System - Manual (Page 37)

Caution: Always use propylene glycol in the coolant mixture. Do not use automotive antifreeze in
place of propylene glycol. Antifreeze contains corrosion inhibitors that will damage the
torch coolant system.
Caution: Always use purified water in the coolant mixture in order to prevent corrosion in the torch
coolant system. See Water Purity Requirements for Coolant Mixture.
INSTALLATION
HT4400 Instruction Manual 3-3
8
Torch Coolant Requirements
The cooler is shipped to the customer without any coolant in the tank. Hypertherm recommends a mixture of 30%
propylene glycol, 69.9% deionized water, and .1% benzotriazole. This mixture resists freezing to +10° F (-12° C)
and contains a corrosion inhibitor (benzotriazole) to protect copper surfaces in the coolant loop. This mixture is
available in one-gallon containers by ordering 028872. 100% propylene glycol is available by ordering 028873.
Caution: For operating temperatures colder than the temperature stated above, the percentage of
propylene glycol must be increased. Failure to do so could result in a cracked torch head,
hoses, or other damage to the torch coolant system due to the torch coolant freezing.
See Figure b-1 chart in Appendix B to determine if a stronger propylene glycol/purified water solution is needed for
your particular application.
Observe the warning and cautions below. Refer to the Material Safety Data Sheets in Appendix B for data on
safety, handling, and storage of propylene glycol and benzotriazole.
WARNING
COOLANT CAN BE IRRITATING TO SKIN AND EYES AND
HARMFUL OR FATAL IF SWALLOWED
Propylene glycol and benzotriazole are irritating to skin and eyes, and harmful or fatal if swallowed.
Upon contact, flush skin or eyes with water. If swallowed, drink water and call a physician
immediately. Do not induce vomiting.
Caution
Use Hypertherm coolant (028872) to reduce the risk of damage from
freezing and to prevent long-term corrosion.