What is dry running?
Under normal operating conditions, the liquid circulates inside the pump and it provides both cooling and lubrication of the rotating parts. Without liquid, frictional heat will be generated, causing the pump to overheat, which will quickly damage the impeller, bearing shaft as well as the pump casing. To counter this, there are a number of solutions; most commonly used are various monitoring systems that trigger an alarm in case of dry running.
Non-Contact System
With IWAKI’s patented “Non-Contact System”, frictional heat is completely avoided, as the inner and outer magnets are designed in such a way that the inner magnet is held in place even during dry running. Thus, contact does not occur between rotating and fixed (static) parts, and frictional heat is thereby avoided.
IWAKI’s “Non-Contact System” has been implemented in MXM and MDM pumps, even in combination with carbon bearings, which have excellent self-lubricating properties themselves. It minimizes friction even during dry running.
The pump can therefore withstand running without liquid for a long time, in some cases up to a few hours, without damages of any kind. This is documented i.a. in this video, where an MDM32 pump from IWAKI is tested without liquid.
