Here are the most effective ways to prevent cavitation in agricultural centrifugal pumps.
- Provide Adequate Net Positive Suction Head (NPSH)
Cavitation occurs when NPSHa (available) falls below NPSHr (required). Improve NPSHa by:
• Raising the water level relative to the pump
• Lowering the pump installation elevation
• Using larger suction pipe to reduce friction losses
• Minimizing fittings, elbows, and check valves on the suction side
• Ensuring suction strainers are clean and unobstructed
- Shorten and Simplify Suction Piping
Agricultural pump sites often use long suction hoses to reach ponds or ditches. These runs cause high friction losses. To reduce the risk of cavitation:
• Keep the suction line as short as feasible
• Use smooth-bore hose or rigid pipe rather than corrugated hose
• Avoid unnecessary flex couplings and swivel joints
• Maintain straight-pipe lengths into the pump inlet
- Prime the Pump Correctly
Air in the suction line reduces NPSHa. Prevent air pockets by:
• Fully priming before startup
• Using foot valves or vacuum-assisted priming systems
• Ensuring all joints are airtight
• Checking for leaks, worn gaskets, or loose clamps
- MaintainProper Submergence
Shallow water pulls in vortices and air. Follow basic submergence guidelines:
• Keep the suction inlet well below the water surface
• Use a properly sized suction screen
• Avoid drawing water near a waterfall, standpipe, or turbulence source
- OperateWithin the Pump Curve
Over-throttling or running far right of the curve increases NPSHr and encourages cavitation. Best practices:
• Select the correct pump impeller diameter
• Avoid significant wear ring or impeller wear that changes the pump’s profile
• Confirm the engine or motor is running at proper speed
• Do not operate too far from best efficiency point (BEP)
- Reduce Solids and Debris Intake
Organic debris, algae mats, and sediment common in agricultural water sources can partially block suction strainers and increase friction losses. Prevent blockage:
• Use a properly sized suction basket
• Inspect and clean strainers routinely
• Consider larger-area suction screens to reduce approach velocity
- Use Pumps Designed for Agricultural Duty
Cornell’s agricultural pumps offer features that inherently help prevent cavitation:
• High-efficiency impellers that lower NPSHr
• Double-volute casings on larger models to balance radial forces
• Delta or cutter impeller options for high-solids or variable-load conditions
• Robust wear rings to maintain proper clearances
