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Why you shouldn’t run a pump dry

A common reason for pump failure is that the equipment has been run dry – whether not primed or, in the case of submersible pumps, not immersed. This is rarely deliberate but always damaging and is something that must be avoided.

Here’s what happens to a pump when it’s activated without the presence of liquid.

1.       Without water or other liquid, a pump’s impeller has no resistance once it starts moving, causing it to run faster. This leads to overheating of other components such as the bearings and shaft. If allowed to run in this way for too long, the impeller can melt and seize onto the shaft, stopping it from moving altogether.

2.       When liquid comes into contact with mechanical seals, a film is created which can provide added protection. This helps to avoid temperature rises and thermal cracking to seal faces.

3.       Water serves a cooling purpose in a pumping application, and without liquid the temperature of the impeller increases much faster, leading to the problems mentioned above.

Larger pumps with heavier impellers are more susceptible to breaking down than smaller machines, although both will eventually fail if run dry for long enough.

Stainless steel pumps (now available from Gibbons) are more durable than plastic models and are favoured in industries such as the food and beverage sector where external parts of the equipment are exposed to water. Regardless of the pump casing, priming is essential prior to use to avoid a period of costly unplanned downtime - not to mention the repair bill.

If your pump has run dry and you’d like to discuss your options for repair or replacement, give Gibbons a call. We supply our own range of high-performance pumps for multiple applications, along with a comprehensive offering from industry leaders Lowara. If it’s more economical to repair your pump, bring it to our workshop where it will be returned to operation by our expert engineers.

For more information, call us on 01621 868138 or email

Pumps & Controls

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