State of the Art Parts: Bearing Cartridge & Adaptor Piece

State of the Art Parts: Hydro Parts Solutions recently supplied a new bearing cartridge and adaptor piece for an OH2 pump from a Caribbean rum distillery. The customer had no spares for these components and was in a critical situation because both parts had failed and were unusable.

The OEM had provided a minimum delivery time of 10-12 weeks for both parts. Because these parts were necessary for the equipment to be returned to service, the customer sought out a qualified vendor who could provide the components in a shorter turnaround time. Hydro Parts Solutions was able to offer a 5-6 week delivery.

This job was particularly challenging because there were no samples to reverse engineer, only rough sketches from the customer. While it is standard to request samples to reverse engineer, because of the tight timeframe, Hydro Parts Solutions created a model using the sketches and the design experience and engineering resources within Hydro. Continue reading

Using Latest Technology to Refurbish a 50-year-old Pump Element

Power pump performance improved with redesign of the first-stage, double-suction impeller and twin volute. 

This project has been divided into two articles. The first, published in the June 2017 Pumps & Systems; the second, published in September 2017 Pumps & Systems.

Written by: Dave Allard & Dr. Gary Dyson
Published by: Pumps & Systems

In the aftermarket business, part replication is not enough. Precision engineering combined with the latest technology are essential for manufacturing high-quality parts. A main boiler feed pump at a Midwestern United States power plant was built in 1967 using sand casting and wooden patterns, now considered outdated technology. Even though the pumps received refurbishment every six to eight years, the pumps continued to have low performance as well as vibration issues.

Using all its resources—including casting simulations, 3-D models, up-to-date foundry casting techniques and considerable engineering data—Hydro fully manufactured a complete element, performed sophisticated testing in the Pumps Test Lab Approved Program (PTLA) certified test lab, and returned the pump to operation within just 12 weeks.

This project involved the manufacture of a complete first stage twin volute and a description of the latent defects.

The pump suffered from ongoing vibration issues which were caused by pressure pulsations at vane frequency. To improve the vibration levels, hydraulic analysis and redesign were required to develop a new, improved design.

This project has been divided into two articles. The first is the manufacturing of the twin volute and the second is the design of a new impeller.

Twin volute stage piece

Image 1. A received bundle showing failure in the twin volute stage piece. Hydro received the internal element and casing (pump bundle, or element) of the pump. (Images and graphics courtesy of Hydro, Inc.)

The first-stage twin volute is a complicated casting, which failed during operation as a result of poor design.

Hydro re-engineered the casting by using sophisticated engineering and 3-D modeling, along with simulation software and 3-D sand printing.

In addition, Hydro identified the opportunity to improve the performance of the pump by redesigning the first-stage double-suction impeller. To improve vane passing frequency, the first-stage double suction impeller was redesigned with staggered and split vanes.

Hydro’s aftermarket services capability provided a completely new replacement element for this high-energy boiler feed pump and also redesigned the castings to eliminate the original latent defect in the casting design.

Hydro provided sophisticated hydraulic engineering improvements to increase the mean time between repairs (MTBR) of the newly manufactured element.

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Analysis & Rerating Solve Pipeline’s Acoustic Resonance Problem

The phenomenon occurs when a system experiences extreme vibration caused by excessive pump pressure and pulsation.

Written by: Greg Matteson & Jeff Johnson
Published by: Pumps & Systems

A North American natural gas liquids pipeline company was experiencing an acoustic resonance issue that cost up to $35,000 a month in maintenance and repair. A six-week project resulted in rerating three American Petroleum Institute (API) designation between-bearing (BB3) horizontal multistage split-case mainline pumps and performing extensive and specific vibration analyses to identify the problem. The project involved designing and manufacturing new impellers using exclusive milled vane technology, conducting API hydraulic performance tests, and returning the pumps into service.

This midcontinent pipeline gathers, processes, stores and transports natural gas—in this case, propane. Because of its geographic location, extreme temperatures and conditions are a factor in the selection of major equipment and components. The pumps operate at 2,917 gallons per minute with 2,926 feet at 1,500 horsepower and 3,560 revolutions per minute (rpm).

The Problem

The pipeline company was experiencing an acoustic resonance vibration problem at the pump crossover, causing major maintenance and repair issues. Acoustic resonance occurs when a system experiences extreme vibration due to excessive pump pressure and pulsation, with frequencies loud enough for humans to hear. This can happen with the use of variable speed drives.

The pulsations are caused by a non-uniform flow from turbulence, sudden change of flow structure, direction or cross-section.

The acoustic resonance had existed since the pumps were installed more than five years ago. Rather than repairing or replacing them, the company performed continuous unscheduled maintenance that cost as much as $35,000 in a single month.

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Advanced Engineering Boosts Reliability in Boiler Feed Pump

This approach incorporated reverse engineering, design verification and casting simulation to address equipment failure.

Written by: Dr. Gary Dyson and Jesse Stinson (Hydro, Inc.)
Publisher: Pumps & Systems / December 2015

 

Pump technology requires the extensive use of castings to form the complex shapes needed to guide process fluids through the machine. The shape of these passages is crucial to the machine’s performance.

Pump designers spend extensive time designing and optimizing the shapes of these passages to optimize the machine’s efficiency. Unfortunately, casting processes cannot always represent the pump engineer’s true design intent, and the manufacturing processes have a direct impact on the machine’s reliability and design integrity. Designers take these processes into account when proposing their designs, but sometimes the deficiencies of the casting process become apparent after a major equipment failure.

One example involved determining the root cause behind the first-stage failure of a Worthington 12-WCND-166 six-stage boiler feed pump. The pump exhibited high vibration and performance degradation, and it was taken out of service. The inspection determined that a crack had resulted from a welded core plug. Continue reading

New 3-D Casting Methods Produce Spare Parts Faster

Additive manufacturing also improves geometric tolerances.

Written by: Jesse Stinson (Hydro Parts Solutions) & Werner Barnard (Hydro Inc.)
Publisher: Pumps & Systems / March 2, 2015

 

An increasing number of industrial plants are reducing the spare parts inventories stored at their facilities. At the same time, they are replacing fewer pumps because of capital constraints and have determined that remanufacturing existing equipment is the best path forward. Many of the pumps within these facilities have exceeded 50 years of service. This drives the need for replacement parts and, in some cases, emergency replacement parts. Considering the age of these pumps, the replacement parts from the manufacturer are likely obsolete and may not be easily available. Further complicating the situation is the location of manufacture. Many cast parts are manufactured outside the U.S and have long lead times.

To address these challenges, many companies are developing technologies to meet the specific and growing demands of the industry. Many of these advanced tools, including coordinate measure machine (CMM) technology, allow for quicker emergency repairs, faster deliveries and higher quality pump parts.

Image 1. New bronze impeller casting (Images and graphics courtesy of Hydro Inc.)

Image 1. New bronze impeller casting (Images and graphics courtesy of Hydro Inc.)

Figure 1. Reverse engineering raw scan data

Figure 1. Reverse engineering raw scan data

Emergency equipment repairs are common throughout the industry. Having fewer spare parts makes this classification of repair more challenging. Standard equipment repairs typically take six to eight weeks, while emergency repairs must be completed within one day to three weeks, depending on the severity of the situation.

This type of repair often drives the need for rapidly supplied cast parts, which traditionally require long lead times because of the use of wooden tooling to create the mold to manufacture the casting.

Recent advancements in 3-D technology, known as additive manufacturing, allow the cast parts manufacturer to meet customer demands by eliminating the need to create traditional tooling.

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