DC Water’s Blue Plains Advanced Wastewater Treatment Plant is the largest advanced wastewater treatment plant in the world. It covers 153 acres and has a capacity of 384 million gallons per day (MGD) and a peak capacity of 1.076 billion gallons per day. This massive facility, commissioned in 1937, consists of hundreds of rotating assets that must operate efficiently to effectively support the needs of customers in a multi-jurisdictional area.
In recent years, DC Water’s Equipment Reliability Group focused efforts on improving overall equipment reliability through effective lubrication management. With thousands of rotating assets, equipment reliability is a critical issue, as many of the machines have been in service for nearly 30 years.
The Old Business as Usual
As with many large organizations, the lubrication program evolved from a time when lubrication management was not well defined or documented. Historically, lubrication management has been the responsibility of the individual mechanic or millwright completing the work. Generally, anyone who needed oil or grease could order any type or amount of lubricant to complete the task at hand. The result was an excessive amount of new, unused oil and grease stashed in every corner of the plant. The goal was to have easy access to lubricants at the point of use, which is critical in a plant the size of Blue Plains. However, with little to no oversight, this practice quickly created an environment in which misapplication, poor quality control and a host of other poor practices resulted in inflated up-front lubricant costs, followed by unexpected downstream reliability issues.
DC Water has a long history of using oil analysis to guide the maintenance program. One of its first efforts was to implement an internal oil analysis program that utilized a benchtop minilab for immediate results and quick action. As with many organizations with a huge amount of grease-lubricated equipment, technicians know early on that their grease selection and application practices need to be improved. The Equipment Reliability Group believed DC Water was not getting sufficient product life from bearings and there was either over or under lubricating. The fact was incorrect amounts of grease were being applied to most bearings based on industry accepted guidelines. The next action was to investigate and implement an ultrasonic greasing program to add much needed precision to the mechanical reliability program.
Although these efforts are typical of world-class programs, the team soon realized the efforts were not addressing the root causes of some of their most common problems. Although an oil analysis program was helping to assure quality in lubricants, the technicians often didn’t get the right information necessary to make decisions on equipment maintenance. Additionally, though its ultrasound program was adding precision to the grease program, the team suspected the technicians weren’t always using the correct or optimal lubricants in all applications.
Even after the team’s initial efforts, there was a consensus that the lubrication program still had plenty of room for improvement. Like many others before them, they really didn’t know where to start. Wanting to learn best practices, they sought professional help to support their improvement program with a site-wide benchmark assessment of the lubrication program.
The assessment documented how DC Water approached lubrication. The assessment covered three days and was divided into 10 areas of lubrication, including:
- Equipment Maintainability and Contamination Control;
- Lubricant Storage, Handling and Dispensing;
- Lubricant Application Practices;
- Oil Analysis Basics;
- Oil Sampling Practices;
- Training and Education;
- Lubricant Purchasing, Selection and Quality Assurance;
- Lubricant PM Optimization;
- Lubricant Scheduling, Tracking and Reporting Metrics;
- Leakage Control, Safe Lubricant Handling Practices and Environmental Compliance.
The team conducted and documented inspections in every area of the plant regarding the 10 key areas of lubrication. Based on the information gathered, a grade in each area was awarded with a maximum score of 10.
The assessment’s results were largely as expected. Even though an oil analysis program was underway, the reports only told the team that it hadn’t really made a consistent effort in areas like contamination control and storage and handling. Most of the equipment was still equipped with original equipment manufacturer (OEM) air filters that were allowing moisture and small particles to enter freely into the equipment. They also treated the new lubricants as clean and dry and ready for immediate use. The contamination from these two practices was noted in the analysis, but there was no comprehensive strategy to address the issues.
Figure 1: Benchmark of 10 key areas of lubrication
While they felt the correct condition-based volume of new grease was being added based on the use of ultrasonic feedback, they still were not seeing the life span projected for the bearing systems. A detailed asset by asset audit was not conducted during this assessment, but it was noted that some lubricant selections were clearly incorrect. The most apparent examples were the extreme pressure (EP) grease selected for use in electric motors and the use of another EP2 grease used in couplings. These greases did not have the correct base oil viscosity or additive packs needed for the selected components.
The Impact of Lubrication on Machine Reliability
There are several ways maintenance organizations can learn about the impact lubrication has on machine reliability. Conferences, published articles, collective team experience and training all provide conduits for knowledge transfer. However, few catalysts illustrate the impact as bluntly as equipment failure.
Over the years, many experts have attempted to quantify the cost of lubrication in their plants. The biggest challenge is calculating assumptions on the lubrication program because most organizations don’t typically collect and trend lubrication-specific data. Some studies suggest that in extreme cases, plants will lose up to 30 percent of their annual maintenance budget to the downstream effects of poor lubrication. On average though, the figure is closer to 10 to 15 percent, which is still a significant number. A plant with a $10 million annual maintenance budget is expected to waste $1 million to $1.5 million through poor lubrication practices. The problem is many organizations do not know how to properly identify what poor lubrication actually is.
Poor lubrication can be defined as any of the following:
- Over lubrication;
- Under lubrication;
- Wrong lubricant (e.g., base oil, additives, thickener type);
- Poor or nonexistent contamination control;
- Poor storage and handling practices;
- Incorrect application methods;
- Poorly trained technicians.
Many in the industry are not informed enough to identify poor lubrication practices because they don’t yet know if they are over or under lubricating, using the wrong oil or grease, or not properly addressing contamination or storage.
For generations of technicians, the focus in maintenance has been on trying to anticipate when a machine or component was likely to fail and what the consequence (e.g., downtime, cost, safety) of that failure would be. There was little attention given to the root cause of those failures. When evaluated on a cost-benefit basis, approximately 50 percent of PM tasks have essentially no value. Activities, like time-based oil drains, calendar-based filter replacements and high frequency lubrication preventive maintenance, are all merely guesses and most of the time, fail to add any value. In fact, many of these activities are detrimental to the health of the lubricant and, ultimately, the machine.
For example, on the surface, a task as simple as adding a little too much grease to a bearing a little too often can have significant effects down the road. Over greasing a bearing results in added visits and more product than necessary, so there is a cost associated with the labor and the material. The excessive grease envelops the bearing, insulating it so it holds in more heat. This additional heat leads to the rapid onset of oxidation, which creates by-products that can damage the bearing’s surface and reduce its overall useful life span. If a bearing is over greased today with the wrong grease, it’s unlikely it will catastrophically fail tomorrow. However, instead of that bearing running trouble free for 15 years, perhaps the life of the bearing has been reduced to five or six years. When you start to add up the lost productivity of that bearing, the cost of the replacement and the potentially hundreds of examples like it in the plant, the financial impact really adds up.
The First Step
As a result of the assessment, the Equipment Reliability Group realized its approach to lubrication was potentially costing a significant amount. Even though the group had been progressive in its program over the years, it was still relying on estimates and projections with respect to the lubrication program. It was clear an overall plan based on actual data was needed.
One of the primary deliverables from the initial assessment was the development of an action plan. The action plan was a task list of nearly 50 discrete items that detailed improvement possibilities in each of the 10 key areas of lubrication. One area in which the group knew needed improvement was lubricant storage and handling. The team learned that if it didn’t get lubricants into a condition suitable for in-service use in the storage area, it had little chance of achieving this in the plant environment. The group also learned that in order to mitigate the risk of additional equipment contamination during oil changes and top offs, technicians needed to prefilter the new lubricants. As a general rule, oil should be filtered to two ISO codes cleaner than the target cleanliness of the component for which it is intended. This will account for practices in the field, such as small volume top offs, that cannot be avoided and may potentially allow contaminants to enter the system.
DC Water was able to design a fully functional lubricant storage and handling room, with equipment designed to make the job more efficient and effective. The technicians realized that by making improvements in how they store and handle their new lubricants, they were able to improve in other areas, as well. They knew their new oil was free of dirt and water and several times cleaner than the oil in service. This adds important context when reviewing oil analysis reports. All the potential noise from dirty makeup oil was removed, allowing them to focus on real root causes when they saw a potential increase in solid contaminants or water.
Figure 2: Diagram of lubricant storage and handling room
The Next Step
The assessment identified some things DC Water was doing very well and some things that needed attention. The assessment’s recommendations included implementing several practices that hadn’t been previously considered. DC Water started to leverage what it did well and focused on implementing some of the new recommended practices.
The next step was to make sure technicians were using the correct lubricant in the correct place. Though the entire plant isn’t very old relative to most industrial plants, the lubricants in use have changed over time. This happens for a number of reasons: plants change lube suppliers, lube suppliers add and remove products from their product line, errors in selection and OEMs not providing enough specific details to select the optimal lubricant.
DC Water engaged professional assistance to collect the data needed to determine the right lubricant in the right amount and frequency and provide a complete lubrication policy. This included plans for each asset class on how best to make minor modifications so that maintaining equipment from a lubrication standpoint and controlling contaminants were easier and more effective.
Progress Toward World-Class: Where DC Water Is Today
Lubrication programs are ever-changing. As the demand on equipment changes and machinery and lubricants age, DC Water must adjust its lubrication program accordingly. With this understanding, DC Water continues to move toward world-class lubrication while consistently evaluating the lubrication process from cradle to grave.
Since implementing the program, the Equipment Reliability Group has been able to identify some quick fixes. For example, identification of equipment with significant leakage problems has become easier with a well managed program. Additionally, knowing what an ideal lubricant volume and consumption look like plant-wide makes it far easier to maintain a realistic inventory of lubricants. These examples, along with many others, help explain the ongoing cost of the lubrication program, which will improve accuracy when forecasting budgets in the future.
As DC Water continues down the path to world-class, it plans to improve on benchmarking by creating key performance indicators (KPIs) from oil analysis data entered into its computerized maintenance management system (CMMS). The plan is to use this data to better understand asset life expectancy of equipment in its normal operating context. Optimizing PMs, more efficient planning and scheduling, and identifying root causes and failures earlier to minimize the impact are all additional benefits DC Water is looking forward to realizing.
Figure 3: DC Water’s lubricant storage
A wastewater treatment plant of this magnitude has a vast amount of rotating assets that require many different types of lubrication tasks. DC Water’s Equipment Reliability Group (manager Phil Higgins, Gerald Wheeler, Edward Blankenship, John Adams and Coralynn Smith) works relentlessly at designing and implementing a lubrication program that uses industry best practices and produces tangible data that will support and justify its efforts to increase the asset’s life span.
With any lubrication program, it’s extremely important to approach it as a journey without an end. DC Water will continue to introduce new technologies to its mechanical reliability program as it fine-tunes its lubrication program for continued success.
A special thank you to Phillip Higgins, former Reliability Manager at DC Water, for his contribution to this article. Phillip has retired from DC Water since the writing of this article.