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Articles in Industry Publications

Axial Thrust in Rotodynamic (Centrifugal) Pumps

  • February 2024
  • Number of views: 1457
Webinar recording

When repairing centrifugal and axial flow pumps, axial thrust is a concern. An understanding of the causes and the mitigating provisions of various pump designs will help repair technicians to ensure those provisions work properly.

Adjusting End Play on Vertical Pump Motors

  • January 2024
  • Number of views: 1398
Video

This video walks through the steps to adjust and set end play on a typical vertical hollow shaft pump motor.

Submersible Pump Seal Fluid Guidelines

  • November 2023
  • Number of views: 1673
Article

There are many considerations for selecting a barrier fluid in general, but only a few apply to submersible pumps. When the fluid specification cannot be found or when the specified fluid is not available for the repair, there are some general guidelines to follow that are offered here.

Pautas Para el Fluido de Sellado de las Bombas Sumergibles

  • November 2023
  • Number of views: 1534
Article

En general, existen muchas consideraciones para seleccionar un fluido barrera, pero sólo unas pocas aplican a las bombas sumergibles. En casos en que no se pueda encontrar o no esté disponible el fluido especificado para la reparación, este artículo ofrece algunas pautas generales que se pueden seguir.

Importancia del punto de mejor eficiencia (BEP)

Entendiendo los factores involucrados para determinar el desempeño de la bomba

  • September 2023
  • Number of views: 669
Article

Cuando trabaje con bombas, seguramente encontrará instancias en las que se hace referencia a la curva de la bomba, junto con una serie de parámetros asociados con ella. Un parámetro clave de la curva de la bomba es el Punto de Mejor Eficiencia (BEP). Este concepto simple de un punto de operación que produce la operación más eficiente no es difícil de visualizar. Para motores eléctricos, la eficiencia varía con la carga; la mejor eficiencia está en alrededor del 75% de carga. Sin embargo, con las bombas rotodinámicas, que incluyen bombas centrífugas y de flujo axial, hay que considerar cuatro parámetros clave, uno de los cuales es la eficiencia. Estos cuatro parámetros son cabeza, caudal (también conocido como capacidad o volumen), potencia y eficiencia.

Common Causes of Surface Damage in Pump Impellers

  • March 2023
  • Number of views: 3230
Article

It’s common to find pump impellers with significant surface damage. The three most common causes of surface damage are erosion, corrosion and cavitation. For each of these there are characteristics which will help indicate the primary cause of the damage.

Causas Comunes del Daño en la Superficie de los Impulsores de las Bombas

  • March 2023
  • Number of views: 3709
Article

Es común encontrar impulsores de bombas con daños significativos en la superficie. Las tres causas más comunes de daño superficial son la erosión, la corrosión y la cavitación. La apariencia del daño en las superficies del impulsor refleja las características de cada uno de estos tres fenómenos.

Repairing Corrosion and Erosion Damage on Pumps

  • May 2022
  • Number of views: 4649
Article

Corrosion and/or erosion damage is inevitable for some pump applications. Pumps received for repair with significant damage may look like a candidate for the junk bin, but with proper repair techniques can often be restored to original performance – or perhaps better than original.

Reparando Daños por Corrosión y Erosión en Bombas

  • May 2022
  • Number of views: 3893
Article

En algunas aplicaciones, los daños por corrosión y/o erosión de las bombas son inevitables. Las bombas enviadas para reparación que presentan daños significativos pueden parecer buenas candidatas para ser desechadas, pero a menudo con las técnicas de reparación adecuadas pueden restaurarse a sus condiciones originales o quizás a unas mejores.

Sizing Pumps and Pump Motors

Important considerations for your application

  • January 2022
  • Number of views: 3077
Trade press article — Modern Pumping Today

End users or service centers often need to specify replacement pumps or pump motors, sometimes involving a retrofit or re-application project. A successful outcome depends on accurate assessment of application requirements and a good understanding of the parameters that govern pump performance.

Sizing Pumps and Pump Motors

  • July 2021
  • Number of views: 9198
Article

Service centers are often called on to provide replacement pumps or pump motors or to advise on pump retrofit and re-application projects. A good understanding of the parameters that govern pump performance is essential to help customers with these opportunities. The information here relates to rotodynamic pumps (centrifugal and axial flow impellers) and not to positive displacement pumps.

Dynamic Balancing on Pump Impellers

  • February 2021
  • Number of views: 12844
Article

As with most other machines commonly repaired in EASA service centers, dynamic balancing on pump impellers is an important concern. Excessive imbalance imparts forces on bearings, reducing their lives and subjecting machine mountings to vibratory energy that deteriorates foundations.

Balanceo Dinámico de los Impulsores de las Bombas

  • February 2021
  • Number of views: 11340
Article

Al igual que con la mayoría de las otras máquinas reparadas comúnmente en los centros de servicio de EASA, el balanceo dinámico de los impulsores de las bombas es una cuestión importante. El desbalanceo excesivo imparte fuerzas sobre los rodamientos, reduciendo su vida útil y sometiendo los soportes de las máquinas a una energía vibratoria que deteriora las fundaciones.

Help Customers Save Energy & Money with Power Drive Systems

New study shows major savings potential with power drive systems on commercial pumps

  • December 2020
  • Number of views: 9450
FREE for Members of EASA
Webinar recording

While adding variable speed capability in commercial buildings is not a new idea, a new analysis confirms major energy and cost savings is available by pairing those products with a power drive system (PDS) – regardless of a pump’s load variability. A PDS combines an electric motor, adjustable speed controls and sensors that provide feedback to the equipment, allowing the equipment to slow down or speed up to meet current demand. This idea and the added flexibility a PDS can provide may be even more important as we move forward in uncertain times.

Natural Frequency Testing – Bump Tests and Modal Analysis

  • October 2020
  • Number of views: 13758
FREE for Members of EASA
Webinar recording

Anyone dealing with installed machinery, or even test running motors in the service center, will encounter instances where structural resonance is amplifying machine vibration. The machine may meet stringent specifications in one instance but exceed acceptable vibration levels in another. A good understanding of natural frequencies and the tests necessary to identify them will help solve these vexing situations.

Causes and Solutions for Leaking Pump Mechanical Seals

  • October 2020
  • Number of views: 11105
Article

It is commonly known that pump mechanical seals are temperamental devices that fail frequently. The fact is, mechanical seals are simple devices that are often misapplied, sometimes installed incorrectly, or perhaps installed on pumps that are not well suited for the application.

Causas y Soluciones de las Fugas en los Sellos Mecánicos de las Bombas

  • October 2020
  • Number of views: 8649
Article

Para aquellos que son nuevos en el negocio de la reparación de bombas, los sellos pueden resultar intimidantes, sin embargo, es bien conocido que los sellos mecánicos de las bombas son dispositivos temperamentales que fallan con frecuencia. El hecho es que los sellos mecánicos son dispositivos simples que a menudo son utilizados de forma inadecuada, algunas veces instalados incorrectamente o tal vez montados en bombas que no son aptas para la aplicación. En la mayoría de las aplicaciones, los sellos mecánicos son lo suficientemente macizos para tolerar condiciones de operación y de manejo menos óptimas. Para aplicaciones exigentes todo debe estar bien.

Pump Reliability Essentials

  • July 2020
  • Number of views: 7922
FREE for Members of EASA
Webinar recording

The EASA Pump Reliability Seminar is a two-day program that describes in detail the factors related to pump reliability. This webinar introduces participants to those factors and how they come together to ensure a reliably operating pump.

Determining Impeller Trim Diameters for Pump Re-Applications

  • June 2020
  • Number of views: 7689
FREE for Members of EASA
Convention presentation

Whether it is a simple re-application of a pump from 50 Hz to 60 Hz (or vice versa), the repurposing of an existing pump, or the application of a new pump to an existing application, determining the proper trim for an impeller can be challenging.

Why Pumps Fail

  • June 2020
  • Number of views: 11245
FREE for Members of EASA
Convention presentation

Centrifugal pump failures are most commonly attributed to seal failure, impeller damage and bearing failures. A good understanding of failure modes for seals, impellers and bearings is essential to providing customers with reliable pump repairs.

Making Shaft Lift Adjustments in Vertical Turbine Pumps

Best practices for safe operation and easy accessibility.

  • June 2020
  • Number of views: 10085
Trade press article — Pumps & Systems

Vertical turbine pumps (VTP) commonly have rotors with multiple mixed-flow impellers (sometimes 12 or more) that are supported by a vertical pump motor. Such designs offer a lift adjustment for raising or lowering the pump rotor to properly position the impellers within the bowl. Depending on the type of pump, this may be critical for maximizing pump efficiency and could have a significant impact on motor load (current) and reliability.

How Up-Thrust Occurs in Vertical Turbine Pumps and Provisions to Control It

Up-thrust can occur during shutdown or when the pump is operating at flow rates greater than the allowable operating range.

  • June 2020
  • Number of views: 7703
Trade press article — Empowering Pumps & Equipment

Vertical turbine pumps depend on the vertical motor's thrust bearings to support the combined weight of the pump rotor and the motor rotor and to counteract the dynamic down-thrust that the pump impellers generate in lifting the liquid.

Important Considerations for Accommodating Pump Repair in Your Service Center

  • June 2020
  • Number of views: 6654
Article

It happens to just about every EASA service center. A machine shows up for repair; it has leads, and there’s a motor, but the machine is a pump. Most often, it’s a close-coupled pump or a submersible pump. If your response is, “We don’t work on those here,” because you’re thinking, “We don’t know anything about repairing pumps,” you may be turning your back on some very profitable work.

Consideraciones Importantes Para Acondicionar la Reparación de Bombas en su Centro de Servicio

  • June 2020
  • Number of views: 6486
Article

Esto sucede en casi todos los centros de servicio de EASA, aparece una máquina para reparación, con cables y un motor, pero es una bomba. A menudo es una bomba sumergible o de acoplamiento cerrado. Si su respuesta es: “Aquí no reparamos estos equipos” y está pensando: “Nosotros no sabemos nada sobre reparación de bombas” puede que le esté dando la espalda a un trabajo muy rentable.

Pump Repairs and Procedures

  • April 2020
  • Number of views: 11605
Webinar recording bundle

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

Just $40 for EASA members!

BUY A COPY

Pump Theory and Application

  • April 2020
  • Number of views: 5931
Webinar recording bundle

A special discounted collection of 7 webinar recordings focusing on pump design theory and how to determine is a pump is appropriate for an application.

Just $35 for EASA members!

BUY A COPY

The Pump Repair Option for Service Centers

  • February 2020
  • Number of views: 5011
Article

EASA service centers looking for options for expansion, or to replace evaporating existing electric motor repair markets, have seen pump repair as a good fit. A majority of EASA service centers currently repair roto-dynamic pumps. Pumps are by far the largest category of machines driven by electric motors. If a service center is repairing electric motors, then it is almost certain that some of those motors are driving pumps, and the prospects for pump repair are its existing customers.

La Opción para la Reparación de Bombas en los Centros de Servicio

  • February 2020
  • Number of views: 5007
Article

Los centros de servicio miembros de EASA que buscan expandirse o que estén interesados en reemplazar los mercados de reparación volátiles existentes, han visto en la reparación de las bombas algo idóneo. Por lo general, la mayoría de los mismos repara bombas roto-dinámicas. Por mucho, las bombas son la categoría más grande de máquinas accionadas por motores eléctricos.

Como ocurre el empuje hacia arriba en las bombas de turbina verticales y disposiciones para controlarlo

  • October 2019
  • Number of views: 5374
Article

Las bombas de turbina verticales (VTP) son accionadas por motores verticales provistos con grandes rodamientos de empuje que soportan el peso del rotor del motor, el rotor de la bomba y el empuje dinámico hacia abajo, producido por los impulsores cuando levantan el líquido. El peso del rotor del motor y del rotor de la bomba se determinan fácilmente a partir de datos de ingeniería simples. El cálculo del empuje producido por los impulsores cuando interactúan con el líquido en movimiento es mucho más difícil y no siempre el empuje es generado hacia abajo.

En este artículo revisemos brevemente cómo se produce el empuje hacia arriba en las bombas y las disposiciones en los motores VTP diseñados para controlarlo.

How up-thrust occurs and provisions to control it in vertical turbine pumps

  • October 2019
  • Number of views: 6633
Article

Vertical turbine pumps (VTP) are driven by vertical motors with large thrust bearings that support the weight of the motor rotor, the pump rotor and the dynamic down-thrust generated by the pump impellers as they lift the liquid. The weight of the motor rotor and pump rotor are easily determined from simple engineering data. The amount of thrust generated by the impellers as they interact with the moving liquid is much more complicated, and the thrust is not always generated in the downward direction. This article looks at how up-thrust occurs and the provisions to control it.