A Look at Cavitation Problems and How They Affect Bore Pumps

Have you noticed some strange popping sounds coming from your bore pump while in operation? Well, the reason behind these strange sounds could be traced back to a cavitation problem. Simply put, cavitation is the generation of bubbles or cavities in liquid, produced in somewhat low pressure levels close to the impeller. When these bubbles implode or collapse, they elicit shock waves inside the bore pump, damaging the impeller and the pump housing. Other possible consequences of pump cavitation include excess energy usage and low water pressure. This article addresses the two major forms of cavitation, potential causes and what you should do to solve the situation.

Types of Pump Cavitation

Suction cavitation

When subjected through a low or high pressure condition, bore pumps become vulnerable to suction cavitation problems. Normally, this means that the bore pump isn't getting enough water flow. Consequently, bubbles are likely to form close to the impeller. Even as the bubbles move to the discharge segment of the pump, they are squeezed into fluid due to the adjusted liquid conditions, and end up bursting against the impeller's front surface. As a result, the impeller is bound to suffer a significant material loss and end up resembling a sponge. Here are a few probable causes of suction cavitation:

  1. Bad suction conditions such as low pressure, high vacuum and so on.
  2. Sediment build-up inside the pump causing pressure differences.
  3. The bore pump is shifting further to the right hand side on the pump curve.

Discharge cavitation

When your bore pump's water discharge pressure is extremely high, there's a high possibility of discharge cavitation happening. The high discharge pressure makes it unfeasible for the water to flow unrestricted out of the pump. Basically, water is only flowing inside the pump between the impeller and the pump's casing at high speeds. This leads to the generation of bubbles. Akin to suction cavitation, the explosion of these bubbles elicits mighty shock waves, resulting in serious breakdown of the impeller plus the pump casing. In worst-case circumstances, discharge cavitation may inflict fracture stresses to the impeller shaft. Here are some of the most likely causes of discharge cavitation:

  1. Sediment build-up leading to pressure differences inside the bore pump.
  2. Ineffective pipe design whereby the route taken by the water to enter and exit the pump isn't appropriate for the operations of the pump.
  3. The bore pump is shifting further to the left hand side on the pump curve.

If you're facing any of these two forms of cavitation, get in touch with a plumber for timely troubleshooting and repair.