Contributor: Sam Kelton

Cavitation, or the formation of bubbles or vapor cavities in a liquid, results from rapid fluctuations in pressure. Cavitation causes shockwaves throughout a pumping system as those bubbles burst, and some of the force of displacement is scattered towards different vectors.

Cavitation can create undesirable noise and vibrations, decrease efficiency, and, over time, reduce your equipment’s life span.

Two basic types of cavitation exist in reciprocating pumps:

Suction cavitation can result from obstructed, clogged, or otherwise dysfunctional inlet pipes. When the inlet pipe’s optimal flow is hampered, vapor cavities form near the retracting plunger. Common causes of suction cavitation include:

• Clogged filters
• Pipe blockages
• Sub-optimal piping design
• Disregard of net positive suction head (NPSH) guidelines

Discharge cavitation is the opposite of suction cavitation. This hampers outward flow from the pump fluid end, causing the formation of cavities from rapidly churning fluid trapped inside the chamber.

Many of the same causes of suction cavitation, such as poor pipe design and clogged filters, can also cause discharge cavitation.