Blake Parker
Miembro del Comite de Enseñanza Técnica
Integrated Power Services
Collierville, Tennessee 

Los dispositivos de prueba modernos cuentan con más capacidades que nunca. Consideremos los teléfonos celulares con los que antes solo se podían hacer llamadas, pero ahora funcionan como potentes computadoras que nos ayudan con todo, como el correo electrónico, las redes sociales, la navegación por internet y mucho más. Ahora, los equipos de prueba modernos también han adquirido la capacidad de realizar pruebas multifunción. Incluso compilan el resultado de las pruebas en informes profesionales a todo color. Dicho esto, ¿seguimos necesitando equipos monofunción para diagnosticar con precisión y realizar inspecciones de alta calidad en equipos electromecánicos?

Blake Parker
Technical Education Committee Member
Integrated Power Services

Modern testing devices now have more capability than ever. Consider cell phones. They used to be capable of only making a phone call but now act as powerful computers helping us with everything from email, navigation, social media, surfing the internet and more. Modern test equipment has gained multi-function testing capability also. They even package the tests into colorful professional reports. With that being said, do we still need single function equipment to accurately diagnose and perform high quality inspections on electromechanical equipment?

The pump repairs are completed! Now the pump needs to be tested. This presentation discusses the procedures for the basic tests that can be performed on pumps that have been repaired in the service center.

Final testing of pumps can include:

• Operational tests
• Seal leakage test
• Motor chamber leakage test (submersibles)
• Casing pressure test

While some of these tests are not difficult to perform, knowing the methods and limits will help service centers to confidently deliver quality pump repairs.

The repair of the various types of pumps represents an important segment of the service center repair market. Electric motors and pumps are the two most widely used industrial machine components.

Although there are two principle pump types (dynamic and positive displacement), this manual focuses on dynamic pumps and the fundamentals of dynamic pump repair. The information it contains will be helpful to both novice and experienced pump repair technicians, to supervisors and managers of pump repair operations, and to customer service and sales personnel who communicate with customers about pump repair issues.

Section 2 covers repair concerns and techniques common to most pumps, while the following sections focus on specific pump types and the unique concerns associated with repairing them. These sections include submersible pumps, vertical turbine pumps, end suction pumps and split case pumps. Where appropriate, these sections may reference the general repair information in Section 2.

Table of Contents- (Download the complete Table of Contents)

1. Nomenclature
2. General Pump Repair Procedures
3. Submersible Pumps
4. Vertical Turbine Pumps
5. End Suction Radial Split Pumps
6. Axial Split-Case Pumps
7. Seals
8. Pump Reliability
9. Glossary and Standards Organizations

Gene Vogel
EASA Pump & Vibration Specialist

Service centers that provide field service for equipment removal and installation have little trouble handling most common horizontal pumps. However, vertical turbine pumps (and similarly mounted vertical pumps) present some additional challenges. Vertical pumps of this style use the discharge column to suspend the pump below grade from a grade mounted discharge casing. The casing provides the support for the pump, the pedestal for the vertical drive motor, and a 90 degree discharge elbow. The discharge elbow may be above or below grade.

The initial challenge for pump removal is presented by the length of the pump. Short set pumps range to about 50 ft. (15 meters) in overall length, minus the drive motor. Deep set pumps can extend hundreds of feet (or meters) into a well or sump. The designation as short set or deep set is somewhat arbitrary, depending on the working height of the available crane to lift the machine. A short set pump could be handled as a single piece (again, less the motor). But if the length of the pump exceeds the working height of the crane, then field disassembly is necessary – usually referred to as a deep set pump.

Topics covered include:

• Documenting the condition of the machine
• Overhead clearances
• Reinstalling the pump
• Tests

Doug Moore
Kentucky Service Co., Inc.

Many EASA members perform service on pumps of some type and have had the customer return the pump or call back to say it leaks or it still will not pump. We solved this by making a very inexpensive test center for all types of pumps: flooded suction, immersion lube, submersible, centrifugal, deep well and many others.

Gene Vogel
EASA Pump & Vibration Specialist
and
Walter Barringer
Mobius Institute, Knoxville, TN

Temperature is hot or cold, pressure may be high or low and a tank may be full or empty. But vibration cannot be adequately described by a single parameter. Vibration is composed of amplitude, frequency and phase. Overall amplitude may be used as a simplistic indicator of machinery condition; much like a noise could be described as loud or soft, even though there is a big difference between the scream of a siren and the roar of a train. And so it is with vibration.

The siren sounds different than the train because they are different frequencies. In the same way, the vibration from a failing rolling element bearing can be distinguished from coupling misalignment. This combination of vibration amplitude and frequency is the most common and useful vibration data for determining machinery condition, and analyzing machinery vibration problems. The phase angle of the vibration plays an important role in dynamic balancing and advanced analysis. The analysis of vibration amplitude and frequency as represented in the vibration spectrum, is the topic of this paper.

This paper covers how to get the vibration spectrum and what it means, including:

• Wave form
• Displacement
• Velocity
• Demodulation

Mike Howell
Technical Support Specialist
Electrical Apparatus Service Association
St. Louis, MO

This paper, presented by Mike Howell at the EASA Convention 2015, explores strategies for minimizing calibration costs for measuring and test equipment (M&TE) in service centers. Howell emphasizes the importance of inspection and testing activities, as well as controlling special processes like vacuum pressure impregnation and oven cycles. The goal is to minimize measurement error and ensure that measurement values are close to actual values, which necessitates the calibration of M&TE.

Howell begins by differentiating between accuracy and precision, using an archery example to illustrate these concepts. Precision refers to the repeatability and reproducibility of measurements, while accuracy is the degree to which the measured value agrees with the true value. Calibration, defined as a comparison between M&TE readings and standard measurement units, is crucial for assessing accuracy.

The paper explains the formal definition of calibration provided by the Joint Committee for Guides in Metrology (JCGM) and highlights the importance of not confusing calibration with adjustment or verification. Howell discusses the concepts of Test Accuracy Ratio (TAR) and Test Uncertainty Ratio (TUR), explaining their relevance in calibration processes. TAR is the ratio of the accuracy tolerance of the M&TE to the measurement ensemble, while TUR is the ratio of the accuracy tolerance to the measurement ensemble uncertainty.

Traceability in metrology is another key topic, requiring a calibration hierarchy where measurement uncertainty increases along the sequence of calibrations. Howell provides an example of this chain, starting from a national standard to the final measurement at the service center.

The paper outlines the steps for developing a calibration program, emphasizing the need to control and calibrate all M&TE used for activities affecting quality. Howell suggests compiling information about M&TE in an indexed manner, which can be done through a database or a paper-based system. This information helps service centers decide which M&TE to calibrate internally and which to subcontract.

Subcontracting calibration to accredited laboratories is recommended for certain types of M&TE, as these labs provide tools for managing calibration programs efficiently. In-house calibration is feasible for some M&TE, depending on available standards and personnel skills. Howell suggests starting with micrometers and digital multi-meters, leveraging existing skills and shadowing subcontract calibration suppliers.

The development of a calibration program involves evaluating equipment capability, identifying calibration requirements, selecting standards, establishing a recall system, and implementing documentation and reporting systems. Calibration procedures should be detailed and approved according to service center document control procedures.

Howell also discusses calibration checks, which provide added assurance that M&TE is acceptable for use. Impact analysis for out-of-tolerance conditions is crucial, requiring evaluation of previous measurements and actions based on the significance of the condition.

Finally, Howell emphasizes the importance of minimizing calibration costs through proper planning and sound business decisions. He provides a rough estimate of relative costs for subcontracted calibration of typical service center M&TE, highlighting the potential cost savings from a well-planned calibration program.

Key Points Covered:

• Importance of inspection and testing activities
• Differentiation between accuracy and precision
• Formal definition and process of calibration
• Concepts of Test Accuracy Ratio (TAR) and Test Uncertainty Ratio (TUR)
• Traceability in metrology and calibration hierarchy
• Steps for developing a calibration program
• Subcontracting vs. in-house calibration
• Calibration checks and impact analysis for out-of-tolerance conditions
• Strategies for minimizing calibration costs

Key Takeaways:

• Calibration is essential for minimizing measurement error and ensuring accuracy
• Understanding TAR and TUR is important for effective calibration
• Traceability requires a calibration hierarchy with increasing measurement uncertainty
• Proper planning and documentation are crucial for developing a calibration program
• Subcontracting calibration to accredited labs can simplify program management
• In-house calibration is feasible for certain M&TE with the right standards and skills
• Calibration checks provide added assurance of M&TE accuracy
• Impact analysis for out-of-tolerance conditions is critical for maintaining measurement validity
• Minimizing calibration costs requires sound business decisions and efficient program planning

8 presentations

$40 for EASA members

 

A special discounted collection of 8 webinar recordings focusing on various aspects of pump repair.

Once purchased, all 8 recordings will be available on your "Downloadable products purchased" page in your online account.

Downloadable recordings in this bundle include:

Troubleshooting Pump Performance Problems
Presented May 2017

This presentation covers:

• Not enough pressure (head) or not enough flow – how do you respond?
• How to determine if a pump is operating properly
• Differentiating a pump problem from a system problem
• Determining pump load and power requirements
• The effect of fluid parameters and cavitation on pump performance. 

Target audience: This will be most useful for service center technicians and engineers. The content will also be beneficial for supervisors and managers who are responsible for pump failure analysis and testing. 

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Pump Failure Case Study
Presented December 2013

This presentation covers:

• Brief overview of disassembly and evidence of failure
• Discussion of possible failure scenarios
• Review of actual repairs, modification and reassembly
• Update of machine's present operation

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Repair Tips for Submersible Pumps
Presented February 2013

This presentation focuses on:

• Types of submersible pumps
• Tips on seal arrangements
• Common repair procedures
• Cables and cable entries
• Testing submersibles in the service center

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Assessing Impeller Damage
Presented May 2019

The impeller is generally the most difficult pump component to repair and the most expensive to replace. This session will look at case histories of failed pumps and the steps to determine the cause of failure. Topics covered include:

• Erosion, corrosion, cavitation or wear: What happened to this impeller?
• How to spot the tell-tale signs
• What operational conditions led to impeller damage

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Repairing Impeller Damage
Presented May 2016

We’ve covered how to assess impeller damage. Now learn how to fix that damage. This presentation covers: 

• Replacing/repairing wear rings
• Repairing cavitation damage
• Impeller replacement options
• Dynamic balancing impellers

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Techniques for Straightening Pump Shafts
Presented March 2011

The slender dimensions of many pump shafts make them susceptible to distortion, which affects pump performance and reliability. This recording presents a methodical approach and effective techniques for measuring and correcting shafts which are bent or twisted.

Target audience: This presentation is intended for service center supervisors, managers and machine shop technicians.

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Vertical Turbine Pump Repair Tips
Presented February 2012

Vertical turbine pumps are used extensively in every segment of industry. Although they are not complex, repairing them in the service center can present a few challenges. This presentation gives some approaches and procedures that experience has shown will make the job easier.

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Final Testing for Pumps - An Overview
Presented November 2014

The pump repairs are completed! Now the pump needs to be tested. This presentation discusses the procedures for the basic tests that can be performed on pumps that have been repaired in the service center.

Final testing of pumps can include:

• Operational tests
• Seal leakage test
• Motor chamber leakage test (submersibles)
• Casing pressure test

While some of these tests are not difficult to perform, knowing the methods and limits will help service centers to confidently deliver quality pump repairs.

This presentation focuses on:

• Types of submersible pumps
• Tips on seal arrangements
• Common repair procedures
• Cables and cable entries
• Testing submersibles in the service center

By Gene Vogel
EASA Pump & Vibration Specialist

High vibration is a common problem for motors that are installed on top of vertical pumps. Its source can be a mechanical issue with the pump, motor or coupling or even hydraulic forces from the pump. Structural issues involving “reed frequency” resonance often amplify the problem, but effective diagnosis must begin with an understanding of the underlying vibratory forces. Although the general vertical pump category includes submersibles, this article focuses solely on the ones that most commonly exhibit high-vibration conditions: surface-mounted pumps with the motor bolted to a pedestal on top.

Topics covered in this article include:

• Mass unbalance
• Coupling type and alignment
• Mechanical action of pump shaft & impeller
• Hydraulic action of fluid
• Resonant frequencies
• Basic frequency analysis
• Trim balancing
• Other possibilities
• Vertical pump troubleshooting checklist

READ THE ARTICLE

This presentation covers:

• Head & flow = volts & amps for pumps
• Testing pumps to their performance curves
• Troubleshooting pump performance
• What the pump curve tells you about cavitation 

This presentation covers:

• Not enough pressure (head) or not enough flow – how do you respond?
• How to determine if a pump is operating properly
• Differentiating a pump problem from a system problem
• Determining pump load and power requirements
• The effect of fluid parameters and cavitation on pump performance. 

Target audience: This will be most useful for service center technicians and engineers. The content will also be beneficial for supervisors and managers who are responsible for pump failure analysis and testing. 

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

The paper "Vibration Testing in the Service Center" by Gene Vogel, presented at the EASA Convention 2010, provides a comprehensive overview of the importance, methods, and challenges of vibration testing for electric motors and generators in service centers. Vibration testing is crucial for assessing the condition of machines before and after repair, diagnosing vibration-related issues, and ensuring proper operation post-repair. The paper emphasizes the need for a solid understanding of vibration fundamentals, adequate instrumentation, documented acceptance criteria, proper mounting methods, and awareness of advanced analysis techniques.

Vogel explains that the most common standard for electric motor vibration is the NEMA Standard MG1, Part 7, which specifies maximum allowable vibration levels. Vibration amplitude and frequency are key parameters, with amplitude measured in displacement, velocity, or acceleration units, and frequency measured in cycles per minute (cpm), Hertz (Hz), or orders (multiples of rotating speed). Proper mounting methods, such as resilient mounts, flush mounts, and bolted test-bed mounts, are critical for accurate vibration testing.

The paper discusses the practical aspects of machine mountings and the impact of mounting methods on vibration levels. Resilient mounts, which use durometer pads, are preferred for isolating motor vibration from external effects. Flush mounting and bolted test-bed mounting are also acceptable, with specific considerations for each method. Vertical motors and various pumps present unique challenges for test runs, requiring careful handling to avoid damage and ensure accurate vibration measurements.

Vogel delves into vibration fundamentals, explaining the importance of amplitude, frequency, and phase in vibration analysis. He highlights the need for appropriate instrumentation, such as spectrum analyzers and oscilloscopes, to measure and analyze vibration data. The paper outlines various vibration analysis techniques, including high-resolution spectrum analysis, synchronous-time averaging, and phase analysis, to identify the sources of vibration and distinguish between mechanical and electrical forces.

The paper also addresses common vibration issues, such as unbalance, resonance, and mechanical looseness. Unbalance is characterized by steady amplitude and phase at 1x rpm and is often caused by factors like empty keyways or auxiliary fans. Resonance occurs when the machine mount is tuned to the rotating speed, amplifying vibration levels. Mechanical looseness can result from improper mounting or frame distortion.

Vogel concludes with practical advice for diagnosing and correcting vibration problems, emphasizing the importance of careful analysis and knowledge of available techniques. He notes that while most vibration issues can be resolved through precision balancing, more complex problems may require advanced analysis and troubleshooting.

Key Points Covered:

• Importance of vibration testing in service centers
• NEMA Standard MG1 for electric motor vibration
• Vibration amplitude and frequency parameters
• Proper mounting methods for accurate testing
• Vibration fundamentals: amplitude, frequency, phase
• Instrumentation for vibration measurement and analysis
• Vibration analysis techniques: spectrum analysis, synchronous-time averaging, phase analysis
• Common vibration issues: unbalance, resonance, mechanical looseness

Key Takeaways:

• Vibration testing is essential for assessing machine condition and ensuring proper operation post-repair.
• Understanding vibration fundamentals and using appropriate instrumentation are crucial for accurate testing and analysis.
• Proper mounting methods significantly impact vibration levels and testing accuracy.
• Advanced analysis techniques are necessary for diagnosing and resolving complex vibration problems.
• Regular vibration testing and careful analysis can prevent machine failures and extend equipment life.