Gene Vogel
Pump & Vibration Specialist
Electrical Apparatus Service Association
St. Louis, MO
The paper "Repair Tips for Submersible Pumps" by Gene Vogel, presented at the EASA Convention 2010, provides a comprehensive guide on the types, disassembly, repair, and testing of submersible pumps. Submersible pumps are designed to operate underwater, and their repair requires specialized knowledge and techniques due to their unique construction and operating conditions.
The paper begins by describing various types and styles of submersible pumps, including simple submersibles, cooling jacket-style submersibles, oil-filled submersibles, rail-mounted submersibles, and deep well submersibles. Each type has specific features and applications, such as cooling mechanisms to prevent overheating when the liquid level drops below the motor portion, and rail-mounted designs for sewage lift stations to facilitate connection to discharge pipes.
Disassembly of submersible pumps can be challenging due to the variety of designs and the need for liquid-tight seals. Technicians must have assembly drawings to understand the components and the order of disassembly. The paper emphasizes the importance of releasing pressure from the pump before disassembly to avoid surprises, and the need for proper tools and techniques to remove the stator core for rewinding.
Mechanical seal concerns are addressed, highlighting the use of single and double seals with barrier fluids to prevent seal failure during dry running. The paper provides recommendations for barrier fluids and discusses the importance of proper filling procedures to ensure effective lubrication and cooling.
Cable entries for submersible pumps require special sealing techniques to prevent water ingress. The paper discusses the use of elastomer grommets and potting compounds to achieve effective seals, and the need for careful selection of materials to match the cable dimensions and composition.
Protective devices and controls are essential for submersible pumps, including moisture sensors, temperature sensors, and vibration sensors. These devices help detect operational problems and prevent damage to the pump. The paper describes different types of moisture sensors and their applications, emphasizing the importance of proper installation and maintenance.
Testing submersible pumps involves using a suitable tank of water and pipe fittings to simulate operating conditions. The paper provides guidelines for setting up a test station, including the use of throttle valves and pressure gauges to ensure the pump operates near its best efficiency point (BEP). It also discusses the need for cooling mechanisms during extended tests to prevent overheating.
Key Points Covered:
- Types and styles of submersible pumps
- Disassembly procedures and challenges
- Mechanical seal concerns and barrier fluids
- Cable entry sealing techniques
- Protective devices and controls
- Testing procedures for submersible pumps
Key Takeaways:
- Submersible pumps require specialized repair techniques due to their unique construction and operating conditions.
- Proper disassembly and reassembly are crucial to maintaining liquid-tight seals and preventing damage.
- Mechanical seals with barrier fluids are essential for preventing seal failure during dry running.
- Effective sealing of cable entries is critical to prevent water ingress and ensure reliable operation.
- Protective devices and sensors help detect operational problems and prevent damage to the pump.
- Testing submersible pumps requires careful setup and monitoring to ensure they operate efficiently and safely.
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