Learn warning signs of needed repairs and avoid common mistakes.

Vertical turbine pumps (VTPs) are workhorses in the petrochemical, power generation and manufacturing industries, and prolific in municipal water applications that handle the primary intake load. The ability to develop high head with multiple impeller bowls—coupled with the ubiquity of standard vertical motors that can support heavy pump shaft loads—makes VTPs a good choice. Although these machines are ruggedly built, abrasive sediments in the pumpage take a toll, particularly on line shaft and pump bowl bearings, so periodic overhauls are often necessary. Rather than simply replacing the bearings, however, it is important that repairs address all of the issues needed to restore maximum operating life.

Common Repairs

Common VTP repairs include replacing line shaft and pump bowl bearings, replacing worn shafting, removing corrosion from submerged components and applying corrosion-resistant coatings. Corroded or cavitation-damaged impellers may be repaired and coated or, if badly damaged, replaced.

Pump bowls, suction bells and discharge casings are typically heavy castings that can be reconditioned and fitted with replacement wear rings as necessary. Column sections are similarly reconditioned or replaced if severely corroded.

The discharge elbow that supports the pump (mounted below) and the motor (mounted above) may be less affected by corrosion than submerged components, but special attention is needed to identify and correct any distortion that may have resulted from the heavy stresses applied to this component.

Fit & Alignment

Since line shaft and pump bowl bearings are the most common wear parts for VTPs, repairs should address the fit and alignment of these components. If the discharge elbow and column sections have become distorted, simply replacing the worn bearings will not restore proper running clearances. In that case, the faces and rabbits of the mating components must also be remachined to restore dimensional integrity. Unless special manufacturing equipment is available, this challenging task requires a lathe or boring mill large enough to handle the bulky pump components, and possibly careful engineering to properly support them in the machine tool.

Finish the article online here: https://www.pumpsandsystems.com/best-practices-vertical-turbine-pump-repair

Have you ever heard that water and electricity don’t mix? If so, then the title “submersible pump motor” must sound like a bad idea. However, it is a very common application for electric motors  in a variety of industries. Given the fact that the motor and most of the power cables are under water or something similar to water, your approach to acceptance criteria may need to be tweaked a little from your normal acceptance criteria for electric motors designed to operate in dry environments. Manufacturer’s recommended guidelines for continued operation of submersible pumps/motors include very broad tolerances which would suggest trending as a preferred approach to evaluating insulation integrity and reliability.
 
 Unlike more standard applications of motors where access to the motor connection box is possible for troubleshooting, access to the motor connection box of a submerged pump/motor becomes difficult, if not impossible. This dramatically increases the importance of sound quality control testing of the motor and power cables separately prior installation. Submersible pumps are always subject to condensation within the pump seals and water jacket. The fluid surrounding the cables and insulation creates a vast parallel conductor which lowers the overall insulation resistance-to-ground and substantially increases the overall capacitance-to-ground. The resistance-to-ground values often do not reach the minimum values allowed by the IEEE Standards.
 
Finally, the Submersible Wastewater Pump Association (www.SWPA.org) suggests that a new motor installed in a wet well with cap and cable assembly installed can go as low as 2Mohms to ground for continued operation. As always experience and historical comparison should be guiding factors in your decision as to when low is too low.

If you or your motor repair facility are planning on  moving a motor for installation or repair make sure you use all of the lifting points available by the manufacturer and don’t forget to disconnect the load from the motor. This may be even more important for long frame motors. Using only part of the lift points available or leaving a pump connected to the motor can twist the stator frame resulting in a non-symmetrical air gap between the rotor and stator. This twisted frame will produce elevated 2x line frequency peaks in the vibration spectrum, as well as elevated eccentricity frequency peaks in the current signature spectrum. The worst case scenario may result in premature bearing failure or a rotor/stator rub.

July 6, 2015 Press Release: DECATUR, ILLINOIS 

The Employer Support of the Guard and Reserve (ESGR) of Illinois recognized Decatur Industrial Electric with “Above and Beyond” Award from the US Office for the Secretary of Defense for consistently going beyond the requirements of the Uniformed Services Employment and Reemployment Rights Act to support their uniformed employees. 

The Above and Beyond Award is presented by Employer Support of the Guard and Reserve (ESGR) State Committees to recognize employers at the local level who have gone above and beyond the legal requirements of the Uniformed Services Employment and Reemployment Rights Act (USERRA) by providing their Guard and Reserve employees additional, non-mandated benefits.  This award is given in limited numbers by state committees to employers who have had at least one of their supervisors/managers recognized with a Patriot Award, and who have signed or agree to sign a statement of support (SoS).  Decatur Industrial Electric was awarded the Patriot Award in 2014.

Trent Thompson, President of Decatur Industrial Electric, stated that he was “honored to have be given the award and we are very proud that approximately 1/3rd of the workforce is active or former Military.”

February 27: Governor Rauner paid a visit to Decatur Industrial Electric Tuesday afternoon to find out more about the company and talk to their employees about what he is doing in Springfield to help the manufacturing industry.

“This is a great company providing high quality service and this company keeps manufacturing growing and working in America.” Rauner said to a group of Decatur Industrial employees after he toured the plant.

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The manufacturing industry is seeing a lack of skilled and qualified workers as high school graduates have gravitated towards four-year institutions instead of the vocations. Trent Thompson, President and owner of Decatur Industrial, said that was one of the areas he and Rauner covered as he gave him a guided tour of the plant. “What we do is really cool stuff for people who like to build and make things. There are lots of opportunities out there for great jobs that I would really like to see our education system be bolstered for starting in the junior high level and leading into high school and community colleges.” Rauner supported Thompson by saying that more people need to be trained in the trades because “strong manufacturing and a strong economy are key to the prosperity to the people of Illinois.”

In addition to an increase in vocational students, Thompson talked about the difficulty of being a business in Illinois. Rauner agreed with Thompson’s concerns and said there are a few areas he wants to address with the General Assembly. When it came to the high tax burden recently passed by legislators Rauner said, “I want to roll that back down so you can save that money and keep it in your pocket and you can keep it in your business so you can pay more and grow more.” He added he wants to propose a billion dollar tax cut and lower property taxes.

Another area Rauner covered was “cutting the red tape” that makes it more difficult for businesses like Decatur Industrial to do business. “That red tape and fees and requirements and filings and restrictions raises your costs; keeps you from being as competitive as you need to be; and keeps you from growing as fast. So I want to get that red tape off of you so you can grow and boom.”

Thompson said he would be happy with whatever Rauner and the rest of the legislatures could do to make it easier for him to continue his family’s business and become more competitive in the Midwest. Decatur Industrial Electric has been around for over 65 years and Thompson is the third generation to run the plant. He said they remanufacture equipment to help give customers tools that will last a long time and he wants to see that longevity within their business as well.

Story Credit: 

Now Decatur: Governor Rauner Talks Manufacturing with Decatur Industrial Electric