Gene Vogel
Pump & Vibration Specialist
Electrical Apparatus Service Association, Inc.
St. Louis, MO

The paper "Vertical Turbine Pumps" by Gene Vogel, presented at the EASA Convention 2011, provides a detailed examination of the applications, configurations, and maintenance of vertical turbine pumps. These pumps are essential for various industries, including municipal water systems, waste water management, food processing, flood control, irrigation, and power generation. Vertical turbine pumps are particularly useful for sump applications where the pump must be positioned below the surface to lift water or other fluids for processing and reuse.

Vertical turbine pumps are characterized by their vertical mounting and the discharge that comes up through the column around the line shaft. They often feature multiple impellers in series, which is ideal for applications requiring high head and moderate flow. The paper distinguishes between mixed flow and axial flow impellers, with mixed flow being more common due to their ability to handle higher heads by stacking multiple stages. Axial flow impellers, on the other hand, are used for applications requiring maximum flow at relatively low head, such as flood control.

The physical configuration of vertical turbine pumps includes hung rotors, where the weight of the pump shaft and the force of lifting the liquid are supported by the vertical motor shaft. Self-supported rotors are less common and feature bearings to support the vertical load. The depth of the pump is determined by the number of column sections, which can extend down for hundreds of feet. Guide bearings and shaft tubes are crucial components, with bearings typically being sleeve type and lubricated by the pumpage or fresh fluid.

Key issues in the maintenance and repair of vertical turbine pumps include lifting capacity, field disassembly and reassembly, and the availability of replacement parts. Impellers are OEM items, while shafts and couplings can be sourced from competent machine shops. Structural resonance is a common problem due to the long hanging column and the mass of the impeller bowls, requiring qualified vibration analysis for troubleshooting.

Line shaft bearing wear is a significant concern, as the bearings are often lubricated by the flow of pumpage, which can contain debris that accelerates wear. The paper emphasizes the importance of regular inspection and maintenance to prevent severe vibration and damage. Disassembly difficulties are common due to corrosion and frozen threads, and special tooling may be required.

The paper concludes with practical advice on the repair of vertical turbine pumps, highlighting the importance of precision in machining and the availability of replacement parts. The repair process involves common machining work, and most materials are readily available, except for impellers and bowl castings. Testing can only be done in place, and vibration issues can be complex.

Key Points Covered:

• Applications of vertical turbine pumps
• Types of impellers: mixed flow and axial flow
• Physical configuration: hung rotors and self-supported rotors
• Pump depth and column sections
• Guide bearings and shaft tubes
• Key issues in maintenance and repair
• Structural resonance and vibration analysis
• Line shaft bearing wear
• Disassembly difficulties and replacement parts

Key Takeaways:

• Vertical turbine pumps are essential for various industrial applications.
• Mixed flow impellers are common for high head applications, while axial flow impellers are used for maximum flow at low head.
• Proper maintenance and regular inspection are crucial to prevent wear and damage.
• Precision in machining and availability of replacement parts are important for quality repairs.
• Vibration issues require qualified analysis and troubleshooting.

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