Top 10 Causes Of Entrained Air
Air entrainment occurs when the fluid contains air bubbles before it is pumped. Air entrainment can also be caused when liquid from an elevated point splashes into a wet well, causing turbulence and air bubbles to form. These air bubbles can get picked up and suctioned into the pump during operation. While air entrainment in miniscule amounts can be used to combat cavitation, just 1 or 2 percent air entrainment can cause pump performance to decrease.
Result of air entrainment
As air bubbles become trapped at the pump suction, they block the flow of fluid, leading to a gradual deterioration in pump performance. As flow rate decreases, the developed head will drop off. This leads to an overall decrease in efficiency.
Risks of trapped air
Air entrainment causes increased vibration which leads to bearing failure. Entrained air can also collect in the seal chamber and cause mechanical seals to run dry. A squeal at the start the pump can indicate entrained air when seal faces run dry.
Entrained air can lead to the breaking of pump shafts as the pump may stall one second na pump the next in an endless loop. By introducing unwanted oxygen into the system, air entrainment can result in stress corrosion. It can also cause a pump to lose its prime.
The numbers speak for themselves:
Main causes of air entrainment:
1. Vortexing is the most common cause of entrained air. This
happens to submersible pumps or pumps in suction lift applications
when fluid levels in the tank or pit meets a certain level or
when the static height of the fluid above the suction inlet
If you'd like to find out more about what could be causing
entrained air in your pump (and what to do about it) call our
toll-free number at 1-800- 367-4180. We have experts on hand
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