Submersible Vertical Turbine Pump Maintenance (Part B): Annual Inspection, Bearing Care, and Component Checks

To ensure maximum reliability and longevity of your submersible vertical turbine pump, establishing an annual maintenance routine is just as important as regular monthly or quarterly service. While day-to-day maintenance helps keep the pump running efficiently, annual inspections provide a deeper understanding of the pump’s condition and performance trends over time.

This article outlines the key tasks involved in annual maintenance, including performance data collection, bearing and lubricant checks, and critical part inspections—all essential for preventing unexpected failures and maintaining the long-term performance of submersible vertical turbine pump systems.

Annual Performance Assessment: Establishing and Comparing Baselines

At least once per year, operators should conduct a comprehensive performance assessment of the submersible vertical turbine pump. This inspection should be documented in detail and compared to baseline data collected when the pump was first installed and in optimal condition.

Key parameters to monitor:

Total Head (Pressure Difference): Measure discharge and suction pressure under 3–5 different operating conditions, including zero flow if possible.

Pump Flow Rate: Measure flow corresponding to each operating point.

Motor Current and Voltage: Record electrical performance under all tested conditions.

Vibration: Evaluate pump and bearing housing vibration levels.

Bearing Housing Temperature: Check for abnormal increases that may indicate lubrication or mechanical issues.

Any deviation from the original baseline can help identify component degradation and guide the necessary maintenance actions.

Bearing Lubrication: Best Practices to Maximize Bearing Life

Bearings are among the most critical components in a submersible vertical turbine pump, and lubrication is the primary factor affecting their service life. Most bearing failures are not due to fatigue, but rather improper lubrication practices.

Important lubrication guidelines:

Use non-foaming, detergent-free oil specifically recommended for the pump.

Maintain oil level at the center of the sight glass on the bearing housing.

Avoid over-lubrication — excess oil can cause overheating and foaming.

Cloudy oil may indicate water contamination (>2,000 ppm); if detected, replace the oil immediately.

For pumps with re-lubricable bearings:

Do not mix different greases—always use consistent type and grade.

Clean grease fittings thoroughly before applying new grease to prevent contamination.

Avoid over-greasing, which can cause localized heating and bearing damage.

After re-lubrication, a slight temperature rise for 1–2 hours is normal.

Component Inspection and Replacement Tolerances

If any component failure occurs during annual inspection or disassembly, take the opportunity to inspect related parts for wear or fatigue. Replace components that do not meet the following recommended tolerances:

Component	Inspection Guidelines
Bearing Frame & Feet	Check for cracks, scale, rust, or roughness. Inspect machined surfaces for pitting.
Bearing Frame Threads	Remove dirt and clean thoroughly. Ensure lubrication passages are clear.
Shafts & Bushings	Inspect for wear, grooves, or pitting. Replace if runout exceeds 0.002 inches.
Pump Housing	Replace if wear depth exceeds 1/8 inch. Check gasket surfaces for irregularities.
Impeller	Replace if blade wear exceeds 1/8 inch or if blades are bent, eroded, or corroded.
Bearing Frame Adapter	Replace if cracked, warped, or corroded.
Bearing Housing	Replace if cracked, dented, or worn beyond tolerance.
Seal Chamber / Gland	Replace if wear exceeds 1/8 inch or if grooving, pitting, or erosion is visible.
Pump Shaft	Check for corrosion, wear, and straightness. TIR at seal sleeve or coupling journal must not exceed 0.002 inches.

Conclusion

Annual maintenance is essential for protecting the performance and extending the service life of your submersible vertical turbine pump. By establishing performance baselines, closely monitoring lubrication quality, and thoroughly inspecting critical components, operators can avoid costly downtime, prevent premature failure, and reduce long-term operating costs.

Though comprehensive maintenance requires attention to detail, the long-term benefits—including reduced unplanned repairs, enhanced efficiency, and higher reliability—make it a valuable investment in your pump system’s success. With a structured maintenance strategy, your submersible vertical turbine pump will remain in top condition for years to come.