Pump killers: How to fight the 13 most common centrifugal pump failures? Number 7.

In the series “Pump killers” we investigate the 13 most common causes of centrifugal-pump failure and take a look at the measures that can be taken to fight these ‘killers’. Every week we will share a new, even bigger, killer. Our goal: to reduce the number of victims by sharing our knowledge.

We are slowly heading for winter again. All the more relevant to take a good look at this pump killer. This one may seem obvious to some of you, but it is often overlooked. As a result, we still encounter this killer too often to our liking. That is why we just kick in the "open door" this week: Freezing.

Credit: Popularmechanics.com

In the documentation of the pump manufacturer you can find in which temperature range a centrifugal pump of that type can be used. In practice, things can sometimes unexpected go wrong.

How does this phenomenon arise? It is not surprising that a centrifugal pump is not made to pump solid ice. After all, the centrifugal pump is designed to pump liquids and not solids. It is also probably known that if you let water freeze, for example, the substance expands and takes up more space.

What are the consequences? If there is a risk that a pump that is not in use could freeze due to the environmental conditions, it is best to drain the pump.

Photo: Ripped pump house - credit Oveducon

The photo shows a pump housing of a centrifugal pump that was set up in the open air. The job of the pump was to pump cooling water and keep the temperature in the building within certain margins. On a winter night it would freeze and there was no need for additional cooling. The pump was turned off, because a night of freezing could not hurt. Unfortunately, the next morning the pump was found to be frozen, with the pump housing ruptured by the expansion of the water from liquid to solid.

Unfortunately, this pump was beyond repair and a replacement had to be purchased.

Photo: Heattrace - credit Oveducon

How can this be controlled? Freezing of pumps and pipes can be prevented, for example, by additionally heating the pipes and pumps by means of a tracing ribbon when the ambient temperature falls below a certain value. These are often also equipped with a built-in thermostat that ensures that the ribbon switches on as soon as the temperature falls below a certain value. If the pump is to be taken out of service for a longer period, then pumps and pipes that can freeze in frost should be drained. 

There will no doubt be people who will say about this "killer": "this is not happening to me." We are therefore curious about the experiences of everyone who has had to deal with this "killer". Perhaps this will help to remind others when the temperature does indeed drop below zero!

Next week: number 6.