New Technology Solves Aftermarket Parts Problems

Written by: Dr. T. Ravisundar and Dibu Chowdhury, HydroAire, Inc,. and Heinz P. Bloch, P.E., Process Machinery Consulting
Publisher: Pumps & Systems / March, 2014

 

Industrial equipment users are often confronted with pump parts issues and must make choices. Handling these issues requires making experience-based decisions and prioritizing. How pump hydraulic and wear components in existing inventory are treated is an issue that merits consideration. Plant size, age, past purchasing, maintenance and storage-related practices are among the factors that affect a facility’s status with respect to operational readiness and downtime risk.

As these generally-known facts are applied on a pump component level, it is often determined that the specific pump components in the storehouse may not be the same as the components currently operating in a particular process centrifugal pump. Nor is it always the case that truly optimized components are presently installed. Therefore, the risk of experiencing unforeseen downtime can be reduced by having the right parts on hand. If the parts are truly optimized, installing them at the next opportunity will take the facility beyond being back in business—it will actually take the equipment owners to greater profitability.

To ensure that pumps will perform their intended functions, inventoried or stocked parts should be thoroughly inspected and corrected as needed prior to installation. Incoming inspection is practiced by best-of-class equipment owners and only verified-as-correct parts will be placed in the storehouse. This case study examines a real-life scenario and demonstrates essential precautions that can be taken when procuring pump hydraulic and wear components.

 

A Condensate Pump Repaired & Improved

During a planned outage, a nuclear power plant (NPP) sent a three-stage condensate pump to a highly experienced service center with hydraulic pump design engineers on staff. The NPP provided the hydraulic components, wear rings and bearings from its stock inventory for the pump rebuild project. The hydraulic pump design engineers at the service center performed a thorough inspection of both the disassembled rotor and the parts supplied by the NPP. A visual inspection quickly revealed that the geometry of the replacement impellers did not match the impellers that were removed from the disassembled pump (see Figure 1).

 

Figure 1. Cross-section of a three-stage pump created by an experienced pump repair facility for this three-stage pump. Note semi-open impellers in stages two and three.

 

 

Left: Impeller from disassembled pump
A) Leading edge of vane is straight.
B) Ring turn face to leading edge dist ~ 7/16 inch

Right: Spare impeller supplied from inventory
A) Leading edge of vane edge is curved.
B) Ring turn face to leading edge dist ~ 1inch

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Collaboration and Innovation Result in Efficient Outage

Written by: Paul Gray, Joe Alvey, and Jackson Simmons, Calvert Cliffs Nuclear Power Plant,
Brian Hegarty, Hydro East, Simon Daou, P.E., HydroAire

Publisher: Nuclear News / September, 2013

 

A Hydro East welder repairs the impeller of a Foster Wheeler circulating water pump.

 

 A Hydro East welder repairs the impeller of a Foster Wheeler circulating water pump.

During the 2012 refueling and maintenance outage at Unit 1 of the two-unit Calvert Cliffs nuclear power plant, near Lusby, Md., Hydro East, a subsidiary of Hydro Inc. based in Aston, Pa., supported the on-site overhaul of two large circulating water pumps. Used to supply cooling water to the plant, the Foster Wheeler vertical pumps are 8 ft 3 in. in diameter, 11 ft 5 in. tall, and weigh approximately 25,000 lb.

After the 2012 refueling outage was completed, Calvert Cliffs engineers and Hydro East’s field service team convened to discuss the project, review lessons learned, and generate plans for making the 2013 refueling outage at Unit 2 even more efficient and cost-effective. In preparation, the two groups reviewed the process that had been used in 2012 to remove, rebuild, and reinstall the Unit 1 circulating water pumps, which had been rebuilt on-site. Hydro East’s field service technicians reconditioned the impellers on location, and the Fort Smallwood Fabrication Shop gathered the other parts required to complete the rotating assemblies. The complete disassembly of an entire pump took four 12-hour
shifts, requiring one shift to clean all the reusable parts and another shift to flip and stage the parts. Each shift required a significant number of site resources as well—including security, a crane, and the crane operator—and because other tasks being performed during the outage required the use of some of these same resources, the field service technicians experienced substantial downtime.

To eliminate downtime caused by plant-induced delays—such as having to wait for the crane to become available or for spare parts to be machined—Calvert Cliffs decided to remove the Unit 2 circulating water pump rotating assemblies in one piece and send them to the Hydro East service center to be rebuilt. This plan enabled Calvert Cliffs to achieve cost savings by maximizing the availability of its internal resources and by reducing the number of shifts needed to remove
the pump assemblies from four 12-hour shifts to two. More important, lifting the assemblies in one piece eliminated two high-risk rigging activities for each pump.

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Reverse Engineering: A Strategy for Solving Critical Part Shortages

Written by: Jeff Smith, Hydro Parts Solutions Inc., Dr. T. Ravisundar and Werner Barnard, HydroAire Inc.
Published: June, 2013

 

Reverse Engineering: A Strategy for Solving Critical Part Shortages

The population of industrial pumps is aging. An article from Pumps & Systems’ August 2012 issue chronicled a repair done on an 82-year old pump still in service in a major refinery (click here to read that article). Like this refinery, many industrial operations are using pumps that have been in service 30 to 50 years or more. It is clear the infrastructure of industry is at risk due to the lack of planning by the pump owners and the more limited support from the companies that provided the pumps. To be fair to the pump OEMs, these pumps have been kept in service much longer than a pump OEM would have originally anticipated.

This article will present a case study of a recently refurbished vertical pump, show how the lack of a critical part was overcome through reverse engineering, and will share lessons learned for developing a strategy to overcome part shortages for old or obsolete pumping equipment.

Critical Part Shortage Identified

This single-stage vertical pump in a service water application was sent for repair by a nuclear power plant to Hydro Inc., a reliable independent pump service and engineering provider. A thorough inspection was performed, and although several important parts had to be reverse engineered and manufactured, all but one were machined parts for which raw material was available. One large cast part, a large aluminum bronze suction bowl weighing more than 500 pounds, was identified as the “critical delivery” issue.

 

Severely eroded suction bowl (Photo Courtesy of Hydro Inc.)

Hydro has a highly-skilled in-house engineering team that utilizes process control procedures for reverse engineering under their NUPIC-Audited Quality Assurance Program. Hydro’s organization is one that understands that reverse engineering is NOT the same as “replicating”. Hydro’s engineering team evaluated the critical characteristics of the component, which is essential to developing a replacement part that will meet the same form, fit, and function as the original.

 

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Solutions for Obsolete Parts

Written by: Jeff Smith, Hydro Parts Solutions Inc.
Publisher: Pumps & Systems / February, 2013

 

During the last 20 years of my career, my main focus was on the refining and chemical industries. As I approached retirement last year, I was allowed to make some comments for Pump and Systems related to the problem facing those industries as it relates to the availability of “replacement parts” for pumps that have moved into the age range of 40 plus years; namely, we have a nationwide infrastructure problem if we do not find ways to extend the lives of hundreds of thousands of pumps by having parts availability.

After a brief retirement, I was fortunate enough to find another role to play in the same capacity but more so in the utility industry for both fossil and nuclear power plants. I was actually not surprised to find the same problem; pumps are getting so aged that parts are no longer available. If you give this a little thought you will probably come to the same alarming opinion…..we have a problem that is nationwide and is not industry specific.

The Situation

Just today I visited with a utility company executive who confirmed that this is a problem that is already large and one that will grow AND that thus far there are few initiatives to address the problem. Most people say that when the pump ends its useful life, it will simply be replaced. This ignores the additional and often very considerable capital cost involved in replacing the pump beyond the cost of the pump itself; such as motors, piping, foundations, interruption in service, etc.

The purpose of my comments is to bring light to this problem and to answer a few simple questions:

Who is responsible for addressing the problem? While many will say this is the fault of the OEM and that they should address it, that is simply not correct. The OEM originally sold the pump noting a useful life of 20-25 years. Many pumps are decades older than that. The companies that originally bought the pumps have enjoyed service well beyond the original estimated useful life of the pumps. Our company recently rebuilt a pump that was 82-years old. The owner of that pump should look back on the purchase of that pump as a real bargain. The current owners of these older pumps should accept responsibility for addressing this problem.

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Upgrades Maximize Efficiency of 82-Year-Old Pump

Written by: Bill Rademacher and Jarrod Streets, BP, Jeff Johnson and William Gottschalk, Hydro Inc.
Publisher: Pumps & Systems / August, 2012

 

Photo provided by BP of four IR 24 HV bottom-suction pumps and one IR 24 FV pump (P-15) in BP Whiting Refinery’s water station on Lake Michigan

Positioned on the shores of Lake Michigan are two stations that contain cooling water pumps which feed cooling water to BP’s Whiting Refinery. The #1 water station contains four IR 24 HV pumps, which are large, single-stage, double-suction, horizontal split case pumps. Four pumps in station #1 (P-11, P-12, P-13, and P-14 in the photo below) are unique in that they were designed with a bottom-suction configuration.

 

Photo provided by BP of Cameron performance curve circa 1933

The rotating equipment engineers at the refinery wanted to better understand the operating characteristics of these pumps, which were originally built by Cameron in 1928. Because these pumps were installed so long ago, there was no NPSH data available and the pumps’ best efficiency point was not known.

BP’s rotating equipment engineers contacted Hydro, a reliable pump service provider with whom they had a long and positive relationship. Their initial inquiry for a pump performance test led to a review of the pumps’ operating environment. Hydro’s engineers learned that one pump was a designated spare and three of the four pumps were being run at a much lower capacity. Block valves had been used to limit the discharge pressure for the three operating pumps in an effort to prevent leaks in the cooling water piping inside the refinery.

Hydro’s engineers agreed with the refinery’s rotating equipment engineers that it would be beneficial to obtain the pumps’ best efficiency point. Running the pumps too far back on their operating curves could create internal forces that would be harmful to the pumps and decrease their operating life. For this reason, the refinery decided to pull one of the bottom-suction pumps from service to be tested. However, before sending this pump to Hydro’s independent test lab in Chicago, they seized the opportunity to make modifications that would enable the vintage pump to meet current standards.

The pump was promptly sent to Hydro and a comprehensive engineering analysis was performed. Hydro’s engineers communicated with the refinery’s rotating equipment engineers to determine the modifications and upgrades that could be made.

 

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