Are there water quality requirements?

The following are recommendations for water quality for use with UPT induction Systems to ensure a long service life of the equipment.

As many as 80% of problems with Induction Heating equipment can be traced to water related issues, so maintaining the water system is critical to ensure high reliability.  Failure to meet these water guidelines can void the warranty of the equipment.  Ultraflex Power Technologies recommends the use of isolated water loops for our Induction Heating equipment.  Use of plant water directly in our products can void the warranty.  Water to Air, Chillers, and Water to Water systems are available from UPT, please contact your sales associate for more details.

1) Use clean distilled water, if possible. The following are the recommended water quality specifications:

Specification Recommended Not to Exceed
Total Hardness (CaCO3) 15 ppm 100 ppm
Total Dissolved Solids 25 ppm 200 ppm
Conductivity* <50 μS/cm >50 μS/cm
Max Suspended Solids <10 ppm >10 ppm
PH** 7.0-7.5 <7.0 >7.5

* Water conductivity that is too low (e.g. De-ionized Water) is not recommended.  
** If the pH falls below 4.0 or rises above 9.0, the system should not be used and a system flush/fill should take place as soon as possible.

a. Never use de-ionized (DI) water, as it will damage the aluminum, copper, and bronze fittings.

b. Glycol can help keep the water from becoming too aggressive.  If used, a 30% ethylene glycol (nonconductive type) mixture is recommended with clean water as defined above.

c. Phosphate based corrosion inhibitors are recommended to control the amounts of active ions and help form protective oxide layers on metals.

2) The Ultraflex Power Technology water circuits contain aluminum, brass, copper, rubber, and plastic hose.

a. Ensure dissimilar metals are not used in the water system. The water system should be designed with compatible metals to avoid contamination from items that may rust.  Never use ferrous materials in the water loop such as carbon steel, which will increase conductivity and cause rust and corrosion.

b. While Nonmagnetic Stainless Steel can be used in the water system, it should be located a sufficient distance from the induction heating system to avoid galvanic corrosion between the other metals in the systems such as Aluminum.

c. Water should not be used for other equipment or processes to avoid contamination. In particular, do not use process water for cooling workpieces that are exposed to the environment and contaminants.  If some minor contaminants are possible, the customer should install an in-line strainer to capture suspended particles (> 304 microns).

4) Good water quality requires regular maintenance

a. PH and conductivity levels should be checked quarterly and adjusted as needed.

b. The water system should be flushed to remove sediment and treated with an anti-algae treatment as needed.

c. The water in the closed loop should be changed at least annually and more often if quality deteriorates.

d. Additional maintenance per the manufacturer recommendations should be followed.