Are you responsible for maintaining a water-circulating temperature control system? These questions and answers can help you optimize operation and minimize maintenance downtime.

Circulating-water temperature control systems are offered in single- and dual-zone configurations with temperatures up to 300°F (149°C). Noncorrosive materials of construction provide rust resistance while a canister design ensures a high heat transfer rate.

Perhaps you use a temperature control system to manage process temperatures in plastics processing applications such as molding, melting and extruding. Or, you put it to work for embossing, calendaring or cooking applications in chemical, rubber, metal die casting, printing, or food processing. If you are responsible for maintaining a water-circulating temperature control system, these questions and answers can help you know what to expect.

Q: During Installation, for What Time Period Should I Purge my Water System?

A: This time will vary depending on the size of your process. A good rule of thumb is to watch the discharge pressure gauge while purging. When the gauge becomes steady and the pressure is approximately twice the suction pressure, the system has been purged of air.

Q: What If the Controller Isn't Heating?

A: Suppose the “heat” light is illuminated on the controller and the contactor is in, but the water system does not heat up. Where do you start troubleshooting?

Check whether the heaters are pulling the correct amp draw. The appropriate amp draw is found on the serial tag. If they are, then you may have dirt stuck in the drain solenoid valve; remove and inspect it. If the heaters are not pulling the correct amp draw, you may have a bad heater element.

Q: How Can I Avoid Nuisance Tripping?

A: Suppose your water system shuts down every time the unit calls for cooling. Known as nuisance low pressure tripping, these nuisance shutdowns can be avoided by:
  • Increasing the supply pressure to the system. For normal operation, 35 to 40 psi is recommended.
  • Decreasing the size of your drain line. This will help maintain some backpressure on the system.

Q: How Does the Seal Material Affect Longevity?

A: A silicon-carbide seal has a harder face and can put up with abrasive water conditions. A Viton ni-resist seal is a good, general-purpose seal. Select your pump seal material based on the expected water quality you will be handling with the water-circulating temperature control system.

Q: How Long Should I Expect My Seals to Last?

A: Depending on the quality of the water being supplied to the system, you can expect your seals to last anywhere from one to three years. Other factors that influence seal longevity include the temperature at which the system is being run, and the pressure of the water being supplied to the system. PH