Archive | January/February

143

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July 1, 2007
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Introduction To Synthetic Lubricants & Their Applications

All synthetics are not alike. Selection should be based on the optimum base stock type for the application. The additive system, which also is very important, imparts unique properties to the finished synthetic lubricant. As a result, there can be major differences in performance for the same synthetic type from different suppliers. Case histories and actual field tests are the best way to select a particular synthetic fluid. There are many applications where mineral oils, because of their cost and performance, are perfectly acceptable. Synthetics are problem solvers to be used in applications where their unique properties are cost-justified under the following conditions:

  • Temperature Extremes—Since synthetics contain no wax they are used at very low temperature conditions. ISO 32 PAO and ISO 32 diesters have pour points > -50 F. They also are effective at temperatures well above 200 F, whereas mineral oils should be limited to a maximum of 200 F and synthetics should be considered at temperatures as low as 180 F.
  • Lower Wear—In general, synthetics provide much higher film strength and lubricity than mineral oils, especially in a high-sliding environment that occurs in worm and hypoid gears.
  • Energy Savings—Some synthetics have low coefficients of friction because of their uniform molecular structure, resulting in significant energy savings in many applications.

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Properties & applications of synthetics 

Table I illustrates the most common synthetics and their major applications.

Polyalphaolefins (PAO)… 
If only one synthetic could be selected in a plant, it would be a PAO. These are the most versatile and most widely used synthetics. They operate over a very wide temperature range, can be produced in a wide viscosity range without changing their basic properties and are compatible with most other lubricant types. Because of their nonpolarity, they have poor additive solubility and cause slight seal shrinkage. Consequently, they must be blended with a polar synthetic such as an ester, which swells seals and gives good additive solubility.

Some of the more common uses for PAOs include:

  • Hot and heavily loaded gear boxes: an EP PAO is used for helical and herringbone gears, while a non-EP ISO 460 is commonly used for worm gears.
  • Rotary screw air compressors: PAOs and polyalkylene glycols (PAGs) are the two most commonly used air compressor oils for extended life service.
  • ISO 68 PAO is used in oil mist lubrication of rolling element pump and motor bearings.
  • PAOs have H1 approval in food plants and are used in a wide range of applications.
  • PAOs are not recommended for high-temperature reciprocating compressors because they can form hard deposits on exhaust valves, thus not allowing them to seat properly.

Diesters…
Diesters are one of the oldest synthetic types—and they are limited in the viscosity ranges produced. The most common ISO VGs are 32, 46, 68, 100 and 150. The viscosity indexes are only high for the ISO 32 while the others are in the 70- 100 range, depending on the alcohol and acid used in their manufacture.

The major performance strength for diesters is their excellent solvency minimizing deposit formation. They also have good low-temperature properties and high thermal stability and flash point.

Diesters have a low aniline number and a tendency to swell elastomeric seals. Therefore, resistant seals, such as DuPont Viton, need to be used. Diesters also can hydrolyze in a hot, high-moisture environment—something that
occurs in rotary screw air compressors.

Uses for diesters include:

  • Major application in severe duty reciprocating air and hydrocarbon compressors: diesters’ high thermal stability and excellent solvency will prevent carbon buildup on exhaust valves.
  • The synthetic of choice in air compressors many years ago: diesters are still used, but to a limited extent because of their potential for hydrolyzation. They are blended with mineral oils to form partial synthetics used in air compression and with PAGs for air compression.
  • Diesters are used extensively both in the ISO 68 and 100 viscosity grades for oil mist lubrication of rolling element pump and motor bearings.

Polyol Esters (POE)… 
POEs have very high thermal stability allowing them to be used in a very high temperature environment. They also are fire resistant with high flash- and fire-point temperatures. Because they are readily biodegradable, they can be used as hydraulic fluids in environmentally sensitive areas.

The major disadvantage of POEs is their cost. They are 50% more expensive than PAOs, PAGs and diesters. Although they have a tendency to hydrolyze at hightemperature and high-moisture conditions, POEs are more stable than diesters.

Primary uses for POEs include:

  • Aviation and industrial gas turbine applications where the effective operating range is -40 F to 400+ F, with primary viscosity ~27cSt.
  • Extended life fluid for air compressors: rated >12,000 hours and stable at temperatures of 240 F, which is higher than the maximum temperature allowable in a rotary screw air compressor.
  • Fire-resistant hydraulic fluid for underground mining, steel mills and foundries: Factory Mutual approved and MSHA certified; flash point for ISO VG 46 > 510 F and fire point >680 F.
  • Environmentally friendly hydraulic fluids that are readily biodegradable and contain ashless antiwear additives.

Polyalkylene glycols (PAG)…
As discussed in the first article in this series, PAGs are quite versatile. They can be designed to produce a wide variation in water solubility by adjusting the ratio of ethylene and propylene oxide during manufacturing. They have very high viscosity indexes exceeding 250, as well as excellent polarity for metal surfaces that gives them good lubricity. PAGS don’t produce deposits and can be designed to minimize hydrocarbon gas solubility. Their major weakness is compatibility with hydrocarbon lubricants like mineral oils and PAOs. They also shrink many elastomeric seals and attack certain paint types.

Some primary uses for PAGs include:

  • Rotary screw and centrifugal air compressors
  • Enclosed gear boxes in particular worm gears
  • Fire-resistant hydraulic fluids
  • Food grade products ISO VG 150 and higher needing H1 approval
  • Hydrocarbon-flooded rotary screw compressors
  • High-pressure ethylene compressors in HDPE production

Applications 
This following list highlights several applications where synthetics provide major cost justifications. Many more applications could have been presented:

  • Air Compressors
    • Rotary Screw
    • Reciprocating
  • Hydrocarbon Compressors
    • Rotary Screw
    • Reciprocating
  • Enclosed Gear Boxes
    • Helical, Herringbone, and Spiral Bevel
    • Worm

0707_formulations_img1Air compression
Rotary screw compressors…
 
Most of today’s industrial air compressors are rotary screws like that shown in Fig. 1.

 

In a rotary screw compressor, air is compressed, high temperatures are generated and, along with the moisture that is present, a severe oxidative environment is present for oil. The lubricant in this equipment performs four major functions: cooling, lubricating (bearings, gears and screws), sealing and corrosion prevention. This requires an oxidatively stable lubricant with high VI and good lubricity. Many OEMs have their own fluids—which are mainly synthetics. As shown in Table II, the different lubricants used can be classified based on fluid life.

The expected hours shown in Table II are OEM recommendations on expected life. Depending on the conditions, synthetics may exceed these numbers if the temperature and moisture are lower than normal.

 

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The most common fluids used for air compressors for extended service are ISO VG 46 PAO and PAG/Ester. The esters most commonly used with PAGs are diesters and POEs that swell seals to counteract shrinkage caused by PAG.

POE gives the longest life extension for the fluid and is being used for extendedwarranty applications. Some POEs on the RPVOT test, which is a measure of the oxidative stability of a fluid, give results in excess of 3000 minutes—that’s nearly double the results obtained with PAOs and PAGs. POEs can be used at temperatures up to 240+ F, which is above the shutdown temperature of an air compressor. PAO can handle temperatures up to 220 F and PAGs are lower at 200 F. PAGs have the added advantage of very high viscosity indexes that gives a thicker film at high temperatures which minimizes wear. Furthermore, they don’t form deposits at high temperatures when they oxidize.

Two major cost justification areas for the use of synthetics is in fluid life extension and energy savings. Consider the following case study.

An evaluation was performed on a 300 hp compressor with a 60-gal. sump capacity operating at 180 F. Running mineral oil required change-out every 1000 hours, while a PAO greatly exceeded the OEM recommendation of an 8000-hour change by running 15,000 hours. This resulted in a 67% savings—or more than $1700—in lubricant costs in one year. (Data courtesy of Dr. Ken Hope, Chevron Phillips.)

Energy savings can be significant with air compressors. A number of studies have shown savings between 3-5% with rotary screw compressors. Combining energy savings and longer fluid life, along with less wear and better operation, synthetics make sense for air compression applications.

Reciprocating… 
While reciprocating compressors (Fig. 2) are not used much in air compression today, there are still many old compressors working in the industry.

Because of high temperatures, the cylinder region in a reciprocating compressor is the most difficult area to lubricate. One major problem associated with the use of mineral oils for this application is that they form hard deposits when they oxidize and coat the exhaust valves, thus keeping the valves from seating properly. As a result, hot gas is drawn back into the cylinder to be recompressed. This dangerous condition can lead to high heat generation and a possible fire.

The lubricant of choice for reciprocating compressor applications is an ISO 100 or 150 diester with excellent solvency. Fig. 3 shows two actual exhaust valves. The valve on the left had been running for six months on diester. The valve on the right had been running four months on mineral oil. The valve on diester continued to run with no coking, saving over $10,000 in valve replacement costs.

0707_formulations_img4Hydrocarbon compression Rotary screw compressors…
Non-flooded rotary screw compressors running at temperatures below 180 F can use mineral oils without major problems. Users, however, may want to turn to a synthetic like a diester or a PAO for their energy-saving potential. Flooded screw compressors with hydrocarbon gas will quickly lose their viscosity with most mineral oils and synthetics because the gas dissolves in the lubricant, thus lowering the viscosity.

PAGs are the most resistant lubricant to hydrocarbon gas dilution and are recommended for flooded screw compressors. More resistant to dilution than mineral oils, PAGs will, however, be diluted to an extent with hydrocarbon gases, a fact that must be taken into consideration in selecting the initial viscosity to arrive at the correct viscosity at the operating temperature. PAGs have the added advantage of having very high VIs.

Ethylene high-pressure reciprocating compressors…
PAGs are the lubricant of choice for high-pressure ethylene compressors because of their minimal dilution by hydrocarbon gas. The typical viscosity of PAGs used in this application is 270 cSt. The film integrity at a reasonable viscosity is maintained at very high pressures, leading to low lubricant consumption and very low wear rates.

Low-pressure hydrocarbon compressors…
Mineral oils at ISO VG at moderate temperatures have been used successfully. As conditions become more severe, though, synthetics need to be considered. Both PAGs and diesters are good alternatives. PAOs, however, are not recommended because of their tendency to form hard deposits when they oxidize.

Enclosed gearboxes Helical, herringbone and spiral bevel…
0707_formulations_img5Gearboxes experience EHL lubrication through sliding and rolling motion. A key criterion in lubricating gear teeth is to have thick enough film for the high sliding and shock loads. In many cases, EP additives are effective as anti-scuffing agents and are used in many loaded gear reducers. Parallel and right angle shaft gears such as helical, herringbone and spiral bevel are lubricated normally with an ISO VG 220 with EP. Under abnormal conditions, such as high temperatures and high shock loads, an ISO VG PAO with EP is used. Although PAGs can be used, because of their incompatibility problems, PAOs are preferred. Energy savings are more diffi- cult to attain with high-efficiency gears like helicals, herringbones and spiral bevels. Normally, synthetics have shown efficiency improvements of 3% or less. Therefore, the use of synthetics for these gears is not justified by energy savings alone. A better way to justify in these applications is to take into account how dramatically gear performance is improved under difficult load or temperature conditions when synthetics are used.

0707_formulations_img6Worm… 
Worm gears (Fig. 4) are highly inefficient. They also are good candidates for synthetics. A worm gear is a right-angle gear with non-intersecting shafts. These units consist of a steel worm and a sacrificial bronze wheel. There is very little rolling motion. Most motion is sliding—which causes the high wear and high heat. Worm gears typically can run 90 F degrees or higher than ambient temperatures. Since EP additives can attack bronze, very few EP gear oils had been used in the past. The only alternative had been to use a compounded high-viscosity mineral gear oil—such as ISO 460—containing animal fat for lubricity to protect the teeth during boundary lubrication. These types of lubricants oxidized quickly at high temperatures and didn’t provide a high level of wear protection.

The two most popular synthetics used in worm applications today are ISO VG 460 PAO and PAG. Each will perform very well. Neither of these synthetics contain EP and they both provide a high film strength and score very high on the FZG test that measures scuffing of gear teeth at different load stages. Mobil SHC 634, which is an ISO 460 PAO with no EP, exceeds 13 stages, the highest level on the test. This results in very low wear rates and energy savings.

Efficiency savings in excess of 7% have been documented. Because of their lower traction coefficient (which is the internal friction in the lubricant) PAGs often provide higher efficiency savings—but PAOs do very well. Temperature drops with a synthetic can be 20-30 F degrees. While PAGs are more common in gearboxes in Europe, more are being used in the United States. A PAG, because of its greater energy efficiency, is a good choice for new gears and can be used on other gears only with the proper flushing procedures. Moreover, PAGs attack some paints. A safer choice to convert a worm gear from mineral to synthetic is to use a PAO.

The following is a case history of the conversion from mineral oil to PAO:

A major can manufacturer used double-enveloping worm gears with an average reduction ratio of 60:1. The company was using a compounded ISO 460 mineral oil. On average, the company was experiencing four gear failures per year, each costing an average of $12,500 to repair. Temperatures typically were 200 F—and in some cases got as high as 215 F. The mineral oil was replaced with an ISO 460 PAO and the failures were eliminated. In fact, to date, 18 months later, there still have been no failures in this equipment. In addition, the average temperature dropped across the worm gears by more than 20 F degrees.

Conclusion
Synthetics are real problem solvers. While they can work well and be cost justified, there are many applications where mineral oils will do just as well. Three applications where synthetics can improve equipment operation and provide major cost savings are air compressors, high-pressure and hot reciprocating compressors and worm gears.

Deciding which synthetic to use is very important. Each candidate will have advantages and disadvantages that need to be considered before a final decision is made.

Keep in mind that the same synthetic type from different manufacturers can give different results. Even though the base stocks may be similar, the additive package may impart different properties from one supplier to another. Make comparisons between the data sheets, but let your final decision rest on field performance. Look at case histories and, if possible, run a carefully controlled plant test where meaningful data can be collected. Even though this will not be possible in some cases, definite equipment improvements can still be observed without rigorous testing and data collection. Be sure to document this data. Since synthetics are more expensive than mineral-based oils, you will want to be very accurate in your cost justifications.

Acknowledgements
The author wishes to thank Tim Taylor of Summit and Dr. Martin Greaves of Dow Chemical for their assistance in the preparation of this article.

Contributing editor Ray Thibault is based in Cypress (Houston), TX. An STLE-Certified Lubrication Specialist and Oil Monitoring Analyst, he conducts extensive training in a number of industries. E-mail: rlthibault@msn.com; or telephone: (281) 257-1526.

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200

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January 1, 2007
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Delivering It All: Robust & Value-Added

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Tom Madding, Vice President/Publisher

In our July-August publication, I wrote about the continued improvement and growth at Lubrication & Fluid Power, and how it is our goal to keep getting better at informing you on lubricationrelated issues, technologies and services. We haven’t stopped. In fact, one of the latest improvements can be seen in our name. With this January-February issue, our magazine now officially will be known as Lubrication Management & Technology.

Some things haven’t changed, though, including the editorial team that produces this publication. It takes a strong and dedicated team to effectively cover the many aspects of the lubrication market-management, technology and applications-and we’ve got one. Our editor, Jane Alexander, working with three world-class contributing editors-Ken Bannister, Heinz Bloch and Ray Thibault- will continue to deliver the power-packed, practical information that really matters to people like you, who strive to keep equipment and processes up and running through lubrication best practices. We are confident this editorial, coupled with the contributions of other respected industry experts and lubrication professionals, will continue to help make your operations competitive on a global playing field.

You’ll also want to make note of our magazine’s revamped Web site. Our new online address is www.LMTinfo.com. There you can read articles from both the current print version of the magazine and many of our past issues. We’ve also incorporated a new search engine that looks for your topic in the LMT site, as well as from issues of our sister publication, Maintenance Technology magazine. In addition, you’ll find new links for suppliers, events, training, etc. Spend some time and visit www.LMTinfo.com and familiarize yourself with theses changes and the valuable information we’ve made available for you.

Speaking of online offerings, our e-newsletter alerts subscribers to what will appear in a given issue of the magazine and provides useful links to a range of information. In 2007, it will be distributed more frequently than in the past, and will include more targeted messages on specific technologies, products and services.

MARTS, our annual Maintenance & Reliability Technology Summit, is yet another way we keep you informed. For each of the past three years, this conference has attracted over 500 attendees, who came to learn from noted industry experts and network with their peers on topics in the reliability arena, technology processes and lubrication solutions. This year, new tracks have been added in areas of Emerging Technology and Energy Management Payback. MARTS 2007 will take place March 13-16, at the Donald E. Stephens Convention Center, in Rosemont, IL. Please be sure to visit www.martsconference.com for an in-depth look at the great technical offerings that MARTS has for you. If you’re serious about lubrication management, you can’t afford to miss this event.

Robust and value-added are far more than mere buzz words around our organization; these words define Lubrication Management & Technology. Moving ahead, with a new name, new look, new Web presence and new direction, we intend to continue doing what we do best-delivering for you and your lubrication management programs!

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184

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January 1, 2007
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We Reserve The Right…Or Do They?

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Ken Bannister, Contributing Editor

As a classic car and motorcycle enthusiast, I spend much of my spare time restoring and “playing” with vintage vehicles. Ironically, modern technology, through introduction and use of the Internet, has drastically changed my hobby over the past 5-10 years. In this realm of lightning-fast communication, likeminded individuals engage in continual virtual discussions, passing on a wealth of experiences, techniques and knowledge that would have been practically impossible for an amateur to amass in pre-Internet society.

Recently, during a favorite user group session on MG sports cars, a thread regarding lubricant reformulation generated signifi cant discussion. That’s because vintage vehicles employ simple metallurgy and mechanical systems that are content to run on a variety of quality fuels and lubricants-as long as they contain basic anti-wear ingredients. In the past, old engines relied heavily on ZDDP (zinc dialkyldithiophosphate) to retard engine component friction and wear. Without much fanfare, though, early 2006 saw the introduction of the latest API SM lubricant standard, formulated specifi cally to meet the demands of modern engine design and increased catalytic converter life. As a result, ZDDP has been all but eliminated from virtually every oil manufacturer’s standard oil product. Unfortunately, lacking any knowledge of this reformulation, vintage vehicle owners have continued performing regular oil changes with their trusted lubricant products, only to experience premature failures of critical valve trains and camshaft components-within 1,000 miles of an oil change!

Consumer product manufacturers have always reserved the right to change recipes, formulations or designs at their discretion. When a trusted brand or product is changed, it often is done with little ceremony-or impact to the end user-until someone eventually realizes the “new and improved” product can no longer be trusted.

For example, CocaCola wasn’t able to hide a new recipe (masquerading as the original) from discerning taste buds for long. The corporation soon was forced to reevaluate its new formula.

In the world of lubrication and lubricants, it’s different. The impact of a formulation change is diffi cult to assess-unless a diligent approach to monitoring lubrication-related failures and lubricant composition has been implemented.

Those who have been through a lubricant consolidation program know that you establish a relationship with a lubricant manufacturer in which they become intimate with your lubrication practices, working environment and equipment bearing needs. The least number of lubricants are chosen to deliver optimal reliability in accordance with your needs. Still, conditions and products change from time to time. To protect equipment from premature failure caused by product reformulation, companies can perform the following:

  • Establish agreements with your supplier(s) to inform you of any formulation change, then perform an equipment impact assessment prior to ordering new formulation stock.
  • Inform your lubricant supplier(s) of any changes in work environment conditions, equipment design, new equipment additions, etc.
  • Inform your lubricant supplier(s) of any recurring lubrication-related failure.
  • Perform regular “virgin” stock oil sampling, and compare to the original “virgin” baseline. Contact the supplier if signifi cant formulation change is encountered.
  • If you do not have a lubrication/lubricant management program, START ONE NOW!

Sadly, we live in a “buyer beware” society in which the end user cannot afford blind trust or complacency. Are you monitoring your lubricant quality? Good Luck!

Ken Bannister is the lead partner and principal consultant with Engtech Industries, Inc. E-mail: kbannister@engtechindustries.com; or telephone: (519) 469-9173.

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276

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January 1, 2007
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Lubrication Management & Technology News

SKF EXPANDS SERVICES WITH ACQUISITION OF ILLINOIS-BASED PREDICTIVE MAINTENANCE CO.
In a move expected to strengthen SKF’s position in
reliability services, condition monitoring products, maintenance strategies and consulting services, the company’s subsidiary SKF USA Inc. has acquired Preventive Maintenance Company Inc. (PMCI), of Elk Grove Village, IL. PMCI has 70 employees and annual sales of approximately $10 million. It specializes in predictive maintenance (PdM) services for industrial customers throughout the Pulp & Paper, Metals, Food, Automotive and other industry sectors.

The growing trend in contract reliability services continues to drive double-digit growth in this area, and the strength of PMCI will help position SKF to meet these market demands. SKF intends to use PMCI’s expertise in vibration data collections and analysis, balancing, alignment, ultrasonics, lubrication sampling and thermography to create a primary service delivery organization.

According to Bart Bartholomew, vice president of SKF Service Sales in North America, the addition of PMCI to SKF’s Reliability Service business significantly expands his organization’s geographic coverage for the delivery of SKF knowledge to key customers at the foundational service level of predictive maintenance.

HYDRAULIC INSTITUTE INVITES NEW “STANDARDS PARTNERS” 
The Hydraulic Institute (HI) is now offering the opportunity for engineering consultants and pump users to participate as “HI Standards Partners.” As a Standards Partner, North American corporations, partnerships, sole proprietorships and government agencies that are engineering firms, provide engineering services or are end-users of pumps are eligible to receive a valuable package of HI products and services.

Mechanical Solutions, Inc., a Whippany-NJ-based engineering research and consulting firm active in the pump, compressor and turbine industries, is the first organization to become an HI Standards Partner. Headed by William D. “Bill” Marscher, a past president of STLE, Mechanical Solutions offers analysis, testing and troubleshooting services in a number of areas, including tribological component analysis.

To qualify as a Standards Partner, organizations or individuals will need to establish that they provide pump and pumping system engineering, process or facility design, procurement, project management, construction services, hydraulic or mechanical modeling, analytical methods or laboratory or field-testing to a facility owner, government or vendor, or that they are an end-user of pumps themselves.

For more information, visit www.pumps.org

FORD MOTOR CO. DONATES $150K TO SME IN SUPPORT OF THE FUTURE OF ENGINEERING 
Reinforcing its 25-year commitment to the education of its future workforce, the Ford Motor Company has awarded two grants, totaling $150,000, to the Society of Manufacturing Engineers (SME) Education Foundation. Since 1981, Ford has donated $1,608,000 to the SME Education Foundation for scholarships and other engineering education programs.

“Once again, Ford has demonstrated its leadership in supporting and advancing industry by investing in the future of the manufacturing skilled workforce,” the Foundation’s president Glen H. Pearson noted. “Ford’s ongoing support of the SME Education Foundation’s programs gives young people positive, hands-on manufacturing experiences and exposes them to exciting careers in math, science and technology.”

One grant awards $100,000 to support the SME Education Foundation’s Science Technology & Engineering Preview Summer (STEPS) Program at the University of Detroit Mercy. STEPS is a one-week summer camp that gives middle-school students a look into the exciting world of science and technology through hands-on activities. This early exposure helps young people plan ahead and take the necessary courses in high school to prepare them for engineering degree programs.

With Ford’s past contributions, the University of Detroit Mercy’s STEPS camps have introduced 427 young students to the possibility of pursuing an engineering career at an affordable cost to the students.

An additional $50,000 grant will fund the SME Education Foundation’s Ford Partnership for Advanced Studies (PAS) Scholarship, a grant that has funded the education of eight students to date. The SME Ford PAS Scholarship is awarded to graduating students of the Ford PAS program-a high school curriculum created by Ford that links classroom learning with the challenges students will face in post-secondary education and the workplace. Former PAS students who are applying to college and want to pursue a degree in technology or engineering can apply for the annual $10,000 PAS Scholarship, which can be used at any accredited college or university in the United States.

For more information about these and other programs, go to www.sme.org/foundation

OOOOOOPS! 
In some program materials for the 2007 Maintenance & Reliability Technology Summit (MARTS), the terms “Maintenance Technician Effectiveness,” “Overall Maintenance Effectiveness” and their acronyms, MTE and OME, should have been identified with the registered service mark symbol (SM). All of these terms are service marks of LAI Reliability Systems, Inc.

PLANNED REFINERY UNIT TURNAROUNDS CONTINUE TO DECREASE FOR 2007
According to research by Industrial Info Resources (Sugar Land, TX), the number of planned unit maintenance shutdowns for the North American Petroleum Refining Industry will decrease in 2007, marking the second year in a row for declining planned maintenance. This trend is forecast to change in 2008 as refiners schedule maintenance shutdowns to coincide with the first wave of unit additions associated with an industry-wide plan to increase refining capacity.

A number of key issues have combined to reduce the number of planned refinery unit turnarounds over the past two years including, labor shortages, prolonged longlead equipment delivery times, hurricanes, and strong profit margins. After hurricane Katrina shut down a good portion of U.S. Gulf Coast refining capacity in September 2005, the White House asked U.S. refiners to postpone scheduled maintenance in order to keep production at a high level. That trend has continued today. The number of units scheduled for planned maintenance repairs during the second half of 2006 at refineries located in North America is down by 8% as compared to the same period in 2005. This decrease in activity is arguably being attributed to several different events that occurred over the last year following Hurricane Katrina in 2005.

Labor shortages play a role
Some maintenance projects are being delayed and rescheduled because of a shortage of labor coming from skilled craftsmen such as iron workers, millwrights, pipefitters and electricians. Companies that provide personnel for construction, as well as equipment service providers, are having difficulties meeting demand. Historically, slow petrochemical construction markets over the past decade led to a downsizing of the service industry.

Now, with industrial project activity picking up significantly, not only in the petrochemical sector, but across most sectors such as Power and Metals & Minerals Industries, equipment and service providers are having difficulty keeping up with increased demand. Long-lead delivery times are out as far as two years for some equipment such as pressurized reactors and vessels, and the labor pool is running thin. Deer Park Refining LP (Deer Park, Texas) rescheduled a $35-million fall 2006 turnaround to January 2007.

Other factors
Another factor that may have contributed to the decrease is that there were a significant amount of shutdowns scheduled earlier last year in order for refineries to upgrade process units to produce ultra-low sulfur diesel (ULSD) by the mandated June 2006 deadline. A majority of the refiners scheduled ULSD project tie-ins during this timeframe, resulting in some turnarounds that were originally scheduled for 2007 to occur in 2006.

For 2007, there are currently 257 units planned to be taken offl ine for maintenance repair and overhaul. That’s a decrease of 21% when compared to the 328 units that went down for repair in 2006.

Opportunities in unscheduled repair services
In addition to planned maintenance, there are also opportunities to provide services for unscheduled repairs. Since 2003, there has been an average of 65 process units per month that have been shut down for unplanned reasons. A majority of the units were shut down due to a glitch in the process, but other reasons include fires, hurricane preparation and economic slowdowns.

Looking beyond 2008, refinery maintenance activity is forecast to increase significantly. In a continent-wide trend to increase refining capacity and improve unit efficiencies, the nation’s refineries are planning a large number of unit additions, expansions and upgrades. Over the past year, Industrial Info has reported 430 projects at U.S. petroleum refineries, with a total investment value of $19.8 billion. Scheduled construction starts for these projects range between November 2005 and April 2012.

About Industrial Info Resources
Industrial Info Resources (IIR) is a Marketing Information Service company that has been doing business for over 23 years. IIR is respected as the leader in providing comprehensive market intelligence pertaining to the industrial processing, heavy manufacturing and energyrelated industries throughout the world. For additional information, send inquiries to refininggroup@ industrialinfo.com, or visit the organization online at www.industrialinfo.com

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152

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January 1, 2007
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Companies Work Together To Help Power Gen Facilities

Oil skimming capabilities enhance oil/water separating…

0207_solutionspotlight_img1Power generation facilities depend on oil/water separators to separate oil from wastewater. Such equipment, however, usually is not going to be particularly effi cient when it comes to removing oil once it has been separated from the waste stream. Traditionally, the separator industry has either used overfl ow skimmer pipes or weirs, or has depended upon an outside removal fi rm to pump off the oil. While they are inexpensive to use, skim pipes/weirs have inherent problems in that oil is always left on the surface of the separator. Oil removal services are effective in removing the layer of oil, but they can be expensive. In addition, because they are needed on a continuous basis, oil removal services are an ongoing expense.

Difficult problems 
When oil is not continuously removed from the surface of an oil/water separator, several problems occur:

  • Heavy rain or water fl ow can exceed the design of the separator and wash out the oil buildup.
  • Failure to remove the oil causes excessive oil buildup, which increases the chance for the oil to escape and reduces the area of the separation chamber.
  • The oil layer prevents oxygen from reaching the water, allowing anaerobic bacteria to grow, thus plugging the separator plates and leading to foul odors.
  • As the level is lowered for certain maintenance procedures, or as components are lifted out, the tank walls and interior components become completely oil-coated. Also, if the unit is completely drained, residual oil will escape into the outlet piping and be released downstream upon refi lling the separator when bringing the system back on-line.
  • The oil layer makes visual inspection of the coalescer and components very diffi cult, if not impossible.

 

Innovative solutions
Dave Goding, president of Mercer International, an oil/water separator manufacturer based in Mendham, NJ, chose to take a proactive approach in solving these problems for his customers, many of which are in the power gen market. Mercer already had solved a number of their problems with the gravitydisplacement Compliance Master™ separator, which features fi eld-adjustable coalescer plates.

0207_solutionspotlight_img2Goding wanted to go even further, though. He researched a number of methods to remove oil from the separators and discovered that the installation of a “fl oating tube” oil skimmer with the separating device would eliminate the excess oil. After researching equipment, he turned to Oil Skimmers Inc., a manufacturer that uses fl oating tube technology.

Now, Mercer offers Compliance Master separators to its customers with Oil Skimmers’ Model 6V and Model 5H, which incorporate specially designed fl oating tube collectors that fl oat on the surface of the water. Oil adheres to the outside of the closed looped tube that is continuously driven across the separator’s surface and through a set of scrapers that remove oil. The oil then gravity drains into a collection tank. This movement of the tube draws the oil to itself and assures total surface oil removal.

Both skimmer models are designed to operate unattended on a continuous basis. Their looped tubes are long enough to cover large skimming areas and require little maintenance. In addition to being used on new oil/water separators, these skimmer units are available with mounting systems that allow them to be retrofi tted onto existing oil/water separators.

Welcome results
Goding’s customers are pleased with the results of the attachment of the Model 6V and the Model 5H to their oil/water separators. Using Oil Skimmers’ units in conjunction with his organization’s separators, power gen companies have reported saving both time and money by not having to rely on traditional oil removal methods. These new systems also have eased the environmental concern of oil discharge. When discharges exceed the limit set by the Environmental Protection Agency (EPA), large fi nes must be paid. With the help of oil skimming equipment, oil discharges have been eliminated.

“By offering this product feature with our entire separator line, I become a more reliable, forward-thinking source for my customers,” says Goding. “Our product offering is the only one of its kind in the oil/water separator industry. These oil skimmers solve the problem, and that’s invaluable to me and my customer base.”

Oil Skimmers Inc. offers customized oil skimming equipment and solutions for diverse manufacturing and industrial applications that require dependable, continuous removal of oil from process liquids and wastewater. The company has thousands of systems in operation, some of which have been in service for over 35 years.

Mercer International offers a full line of above- and below-ground separators, as well as existing system retrofi ts, that incorporate Oil Skimmers equipment. Mercer can furnish replacement of a client’s existing brand of coalescer and internals with their proprietary components.

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January 1, 2007
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PROBLEM SOLVERS

Keep It Clean And Keep It Running With Smarter Contamination Measurement

Schroeder Industries introduces its SMART™ Kit (SMK) for the measurement of contamination levels in hydraulic and lubricating oils.0207_problemsolvers_img1 The unit comes complete with the Schroeder TestMate Contamination Monitor® (TCM), making it easy for users to continuously monitor ISO levels in real time. This product can be added as a retrofi t to any of Schroeder’s standard fi lter carts, kidney loops and skids, with no additional modifi cations required. Schroeder carts and kidney loops now can be ordered with the SMK included. According to the manufacturer, these user-friendly SMART Kits help save time by completely eliminating the need for bottle sampling when determining fl uid contamination levels. In addition, the SMK package provides the option of downloading data to a PC for trending.

Schroeder Industries, LLC
Leetsdale, PA

 

Steel-Disk Seals For Protection Of Bearings In Mining Equipment

0207_problemsolvers_img2SKF offers NILOS® steel-disk seals for grease-lubricated roller bearings to provide superior protection against contaminants in mining equipment exposed to extreme levels of dirt, dust and debris. They can further prevent leakage of lubricant and contribute to optimized bearing service life in a wide range of applications, including idlers, crushers and conveyor rollers, among others. Their non-contact, grease-fi lled labyrinth sealing elements consist of laminated steel-seal disks and steel cores. These seals resist axial pressure and will not slip when clamped in the axial direction of both the inner and outer periphery of a roller-bearing ring. In use, they offer additional advantages by minimizing bearing friction losses and heat buildup. They are available in a wide range of shaft and casing diameters and are supplied ready-to-install for quick and easy mounting. They also can be customized to meet application-specifi c requirements.

SKF Linear Motion & Precision Technologies 
A division of SKF USA Inc. 
Bethlehem, PA

 

Digital Control For Electrostatic Oil Cleaning

UAS/Kleentek has introduced a new, easy-to-read digital control panel to its line of electrostatic oil cleaning systems.0207_problemsolvers_img3 The UAS/Kleentek system works electrostatically to draw contaminants of all particle sizes out of hydraulic oil. The new control panel features a text display that shows key operating conditions, including motor amperage and oil dwell time. An optional oil temperature monitor helps protect the system’s components from damage caused by sustained high oil temperatures. The new panel also notifi es operators of errors by displaying the cause of an error in text, rather than numeric code, and activating a fl ashing alarm on top of the control panel’s enclosure. For remote or hard-to-access installations, the unit can be connected to a PLC controller to relay the alarm signal. It has a NEMA 4 rating that allows use in dirty and harsh environments and outdoor conditions. An optional enclosure heater also helps ensure uninterrupted operation of the control panel in cold environments.

United Air Specialists (UAS)/Kleentek 
Cincinnati, OH

 

Coolant Cleaners Help With Machine Accuracy And Cost Reduction

Maintaining clean coolant is important in any operation to ensure machine accuracy and reduce costs. 0207_problemsolvers_img4Eriez ceramic and rare-earth magnetic coolant cleaners extract ferrous particles to help meet tolerances and improve surface fi nish in grinding and metal-cutting operations. These products are effective wherever clean coolant is required, including in oil reclaiming machines. Permanent ceramic magnetic indexing units, available with either a smooth-faced or extended-pole roll, can be used when both ferrous and non-ferrous contaminants are present. According to the manufacturer, its non-indexing models are ideal for applications where little or no non-magnetic contaminants are present in the coolant. The ce- ramic magnetic coolant cleaners remove particles as small as 15 microns. They are available in several sizes and can handle up to 600 gpm of water-soluble cool- ant. The company’s Xtractor rare-earth coolant cleaners remove particles as small as 3 microns. Available in four sizes, the Xtractor units can handle up to 120 gpm of water soluble coolant.

Eriez 
Erie, PA

 

Cost-Effective, High-Capacity Varnish Removal Systems

Seaworthy Industrial Systems’ varnish removal fi ltration solution is a
compact, 0207_problemsolvers_img5self-contained engineered unit incorporating a skid-mounted
circulating pump and fi lter assembly with a built-in drip pan. Designed
to operate continuously in a side-stream mode, it leaves the primary lubricating
oil system untouched. According to its manufacturer, this “set
and forget” capability, coupled with some of the industry’s highest varnish-
holding-capacity fi lters means no service calls and very little regular
maintenance. The company also notes that the system offers one of the
highest fi ltration fl ow rates in the industry, which, in light of the product’s
simplicity, comes in at one of the lowest prices in the market.

Seaworthy Industrial Systems, Inc.
Essex, CT

 

Viscosity Analysis Equipment

0207_problemsolvers_img6Brookfield Engineering Laboratories has released a new, full-color catalog,
featuring the company’s complete line of Viscometers/Rheometers and
Texture Analyzers. New offerings for 2007 include:

  • A more durable ball bearing suspension system as an option for new digital
    viscometers and rheometers or as a retrofi t. This system is ideal for instruments
    that experience exceptionally heavy use, multiple operators or dusty
    and dirty work environments.
  • Single and Multi-Station Controllers for AST-100 Viscometer Systems that
    make in-line measurement and control of viscosity easier than ever.
  • A newly designed, spring-loaded, Quick Action Lab Stand, wherein with the
    push of a button, the viscometer glides up and down, allowing for quick
    positioning and faster measurements.

Brookfield Engineering Laboratories
Middleboro, MA

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504

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January 1, 2007
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Justify Your Equipment Reliability Enhancements

According to statistical reliability data, as much as 65% of the life cycle costs are determined during the design, procurement and installation phases of new machinery applications [Ref. 1]. While design and procurement are important aspects for any application, the installation of the equipment plays a very signifi cant role. A superb design, poorly installed, will give poor results. But, a moderate design, properly installed, will give good results.

Baseplate considerations
Baseplate designs have become less rigid over time. Attention has been focused on the pump end of the baseplate to provide enough structural support to contend with nozzle load requirements. The motor end of the baseplate is generally not as rigid as the pump end. Consequently, the process of shipping, lifting, storing and setting the baseplate can have a negative impact on the motor mounting surfaces. While these surfaces may have initially been fl at, experience shows that there is work to be done by the time the baseplate reaches the field.

The other issue of mounting surface distortion comes from the grout itself. All epoxy grout systems have a slight shrinkage factor. While this shrinkage is very small, typically 0.0002″/in (0.2 mm/m), the tolerances for fl atness and level of the mounting surfaces are also very small. A chemical reaction occurs when the epoxy resin is fi rst mixed with hardener (to which the aggregate is added a little later, so as to form what is commonly termed the epoxy grout). This reaction results in a volume change that is referred to as shrinkage. Chemical cross-linking and volume change occur as the material cools after the exothermic reaction. Epoxy grout systems cure from the inside out, as shown in Fig. 1. The areas closest to the baseplate-to-grout interface experience the highest volume change.

To achieve a proper installation, the reliability team will have paid attention to many requirements: good foundation design, no pipe strain and proper alignment are important, just to name a few. All of these issues revolve around the need to reduce dynamic vibration and prevent component deflection in the machinery system.

Great design effort and cost is expended in the construction of a machinery foundation. Reduced vibration severity and the long-term success of a proper installation are determined by how well the machinery system is joined to the foundation system. The baseplate, or skid, that supports the machine must become a monolithic, virtually integral, member of the foundation system. Twisting of a machine frame or casing must be prevented and machinery vibration should ideally be transmitted through the baseplate to the foundation and down through the subsoil. Failure to achieve such transmission will result in the machinery resonating on the baseplate, as shown in Fig. 2, very often causing consequential damage. Proper machinery installation will give long-lasting benefi ts by signifi cantly increasing mean time between failures (MTBF), extending the life of mechanical seals and bearings and reducing overall life-cycle costs.

Field installation problems of conventional units…
Grouting a baseplate or skid to a foundation requires careful attention to many details. A successful grout job will provide a mounting surface for the equipment that is fl at, level, very rigid and completely bonded to the foundation system. Many times, these attributes are not obtained during the fi rst attempt at grouting, and expensive fi eld correction techniques have to be employed. The most prominent installation problems involve voids and distortion of the mounting surfaces.

Void and bonding issues of conventional units…
The presence of voids at the interface between the grout material and the bottom of the baseplate negates the very purpose of grouting. Whether the void is one inch or onethousandth of an inch in depth, the desired monolithic support system has not been achieved. Voids prevent the foundation system from suppressing resonant and shaftgenerated vibration (see Fig. 2).

Mounting surface distortion of traditional units…
Another field installation problem with costly implications is distortion of the baseplate’s machined surfaces. Distortion can be induced prior to grouting as a result of poor field leveling techniques, or it can be generated by the grout itself.

Hidden budget impact of conventional units…
Correcting the problems of voids and mounting-surface distortion in the field is a very costly venture. Repairing voids takes a lot of time, patience and skill to avoid further damage to the baseplate system. Field-machining the mounting surfaces also involves two resources that are in short supply: time and money.

0207_equipmentreliability_img3

The real concern with correcting baseplate installation problems on site is that repair-related issues are not refl ected in the construction budget. Every field correction is a step backwards, both in time and money. On fixed-cost projects, the contractor must absorb the cost, whereas on costplus projects, the user/client must pay the bill. Either way, there will be extra cost, accompanied, all too often, by controversy and blame-placing.

Pre-grouted baseplates: a better method.
A pre-grouted (or pre-fi lled) baseplate is shown in Fig. 3. In the late 1990s, a Houston, TX-based service company developed a highly effective method that assists in minimizing fi eld installation costs and improving the reliability of pump baseplates [Ref. 2]. Using a pre-grouted baseplate in conjunction with the service provider’s proprietary pre-grouted baseplate procedure accomplishes these worthwhile goals and is able to provide a superior fi nished product. When OEM pump sets are delivered to plant site on pre-grouted baseplates, the pump train arrives 60% mechanically complete.

The procedure referred to includes a comprehensive pre-grout plan that calls for a detailed inspection of the primer system used on the underside of the baseplate, proper preparation of this primer for grouting, inverting and then fi lling the baseplate with a suitable epoxy grout, post-curing of the grout material and a detailed post-grout inspection of the baseplate mounting surfaces. If the mounting surface tolerances fall outside of the API 686 specifi cations for fl atness, co-planar and co-linear dimensions, precision grinding or machining is performed to restore or achieve the necessary tolerances. The use of shims is thus avoided and much future grief thereby eliminated. The service provider mounts and aligns pump and driver.

0207_equipmentreliability_img5

Calculating the value of pre-grouted baseplates…
It has been demonstrated that utilizing the combined hardware and procedural approach spearheaded by a leading provider of pre-grouted baseplate technology will save 30% of the cost associated with traditional machinery grouting methods, and provide a superior fi nished product. It can be inferred that superimposing the somewhat more elusive value of the resulting reliability improvement will substantially lower the life-cycle cost of pump installations that make use of this methodology. (For more details, see Table I that follows this case history.)

New fi eld-grouting method for pre-grouted baseplates…
Conventional grouting methods for non-fi lled baseplates are, by their very nature, labor- and time-intensive. Utilizing a pre-grouted baseplate in conjunction with conventional grouting methods (Fig. 4) helps to minimize some of the cost, but the last pour still requires a full grout crew, skilled carpentry work and good logistics. To further minimize the costs associated with baseplate installations, a new field-grouting method has been developed for pre-grouted baseplate. This new method utilizes a low-viscosity high-strength epoxy grout system that greatly reduces foundation preparation, grout form construction, crew size and the amount of epoxy grout used for the final pour.

New grout-forming technique for pre-grouted baseplates…

With the smooth concrete shoulder of the foundation still intact, a very simple “2 x 4” grout form can be used, (See Fig. 4). One side of the simple grout form is waxed, and the entire grout form is sealed and held in place with caulk. While the caulk is setting up, a simple head box can be constructed out of dux seal. Because of the flow characteristics of the low-viscosity epoxy grout, this head box does not need to be very large or very tall. The low-viscosity epoxy grout is mixed with a hand drill, and all the grout is poured through the head box to prevent trapping air under the baseplate.

0207_equipmentreliability_img6

This new installation method has been used for both ANSI and API-style baseplates with excellent results. With this technique, fi eld experience has shown that a pre-grouted baseplate can be routinely leveled, formed, and poured with a two-man crew in three to four hours. The proof of benefi ts can be readily seen in rigorous fi eld installation cost comparisons. This comparison applies realistic labor costs; it does not take credit for the elimination of repair costs associated with fi eld installation problems, such as void repair and field machining. It is shown on page 19.

0207_equipmentreliability_img7

Cost comparisons
It should be noted that industry experience shows eight men typically involved
in the average size conventional grouting job. Using 2003 data, an actual labor cost of $45 per man-hour was assumed in U.S. installations. Here, employee benefits and overhead charges were included.

Using this information, a cost comparison can then be developed, based on the installation of a typical API baseplate, using epoxy grout, for the conventional two-pour procedure, and a pre-grouted baseplate, using the new installation method. The following conditions apply:

0207_equipmentreliability_img8

In 2003, a baseplate with the listed dimensions could be pre-grouted for $2,969. This expenditure included surface preparation, epoxy grout, surface grinding and a guaranteed inspection. The essential results of following this experienced service provider’s well-defi ned baseplate installation procedure were found to include:

  • Void-free grout installation
  • Proper surface preparation of baseplate underside
  • All machine surfaces fl at, co-planar and co-linear, in accordance with API-686
  • Elimination of the need for costly and less effective field machining
  • 30% cost-savings over the traditional field installation procedure

In conclusion, then, Table I shows a realistic accounting of time and labor for the installation of a typical API baseplate. The total installed cost for a conventional two-pour installation is $6,259. The total installed cost for a pre-grouted baseplate, installed with the new installation method, is $4,194. Aside from the obvious cost-savings, the long-term reliability impact of this void-free and fully co-planar installation is of great importance to reliability-focused pump users.

Payback? 
This is one of the rare occasions where a longer-life, less-failure-risk-inducing product actually costs less than its more maintenance-intensive predecessor alternative. The payback is, thus, instantaneous and the benefi t-to-cost ratio could be called “infinite.” What more could we ask?

References

  1. Stay-Tru® Corporation, Houston, TX
  2. arringer, Paul, and Todd Monroe, 1999, “How to Justify Machinery Improvements Using Reliability Engineering Principles,” Proceedings of the 16th International Pump Users Symposium, Turbomachinery Laboratory, Texas A&M University, College Station, TX.

Contributing editor Heinz Bloch is the author of 17 comprehensive textbooks and over 340 other publications on machinery reliability and lubrication. He can be contacted directly at: hpbloch@mchsi.com

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January 1, 2007
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The Five Rights of Lubrication

Many companies fail to realize the importance of lubrication and the application of its five basic “rights” in achieving world-class machinery reliability. This article examines each of these concepts in detail, along with a summary of best practices including procedures in the selection of the optimal lubricant supplier.

1. Right type
As a first step in the lubrication of equipment, refer to the OEM manual, and contact the OEM if you have any questions. With old equipment, the manual may be outdated and better lubricants may be available. When in doubt, utilize your lubricant supplier along with the OEM.

The two major classes of lubricants are oil and grease. The selection of the type is based on the application. Greases are used extensively in the lubrication of small bearings. As rule of thumb, use oil where possible, because it can be cooled and filtered-this is not possible for many applications where grease is the better choice. The following are applications for grease:

  • To decrease drips and splatters, as grease is an added seal to reduce leakage
  • To access hard-to-reach lubrication points, where lubrication frequency is important and oil circulation is impractical
  • To seal in a lubricant and help seal out contaminants, such as water, dirt and corrosives
  • To protect metal surfaces from rust and corrosion
  • To lubricate machines with intermittent operation
  • To suspend solid additives, such as moly or graphite
  • To lubricate sealed-for-life applications
  • When extreme or special operating conditions exist
  • When machine parts are badly worn
  • When noise reduction is important

Greases are composed mainly of oil dispersed in a thickener with additives. Typical grease is ~ 85% oil. It is the oil in the grease that does the lubricating. The NLGI classifies greases according to consistency with the following grades increasing in hardness: 000, 00, 0, 1, 2, 3, 4, 5, 6.

The most common NLGI grade is #2. At high speeds, #3 may be used and at low temperatures and in centralized systems, #0 or #1 is used.

Most large equipment is oil-lubricated and selection of the right type is critical to reliability. Two major factors in selection of an oil-based lubricant are the correct viscosity and additives in the formulation. For a more complete discussion of viscosity, refer to the article “Basic Principles Of Viscosity And Proper Selection Techniques,” published in this magazine last year. For a more complete discussion of the additive types, refer to one of the installments appearing in another recent series in this magazine, “All Lubricants Are Not Created Equally (Basic Concepts In Formulation Of Finished Lubricants).”

0207_fiverights_img2

OEMs will recommend the correct ISO viscosity grade for their equipment, based on the operating temperature. Table I classifies kinematic oil viscosity in centistokes for industrial lubricants, based on the ISO grade that is the midpoint of a viscosity range +/-10%.

Since grease is made up primarily of oil-which does the lubricating- the correct viscosity must be selected in the grease formulation. Table II provides guidelines on the selection of the correct viscosity in grease. Once the correct viscosity has been determined, the correct lubricant type based on additive composition needs to be selected. Lubricant formulations consist of a base stock and additives. Most base stocks are mineral oils from refining of crude oil. Table III summarizes lubricant composition in various lubricant types.

0207_fiverights_img3

2. Right quality
Once the right type of lubricant has been selected, it is important to select a high-quality lubricant. Quality is both the ability of the lubricant to meet OEM specifications, based on performance on ASTM tests, and the cleanliness of the fl uid in which is delivered. You can have the highest quality lubricant, but if it is not handled properly during delivery or storage, it will not perform the way you expect it to.

Product data sheets provide useful information on lubricants and their behavior on ASTM tests, which, in turn, provides insight on their performance on equipment. The best test for a lubricant is how it has performed in YOUR plant, but there are some situations where a lubricant is selected only on specification tests. In 2005, a series of articles was published in this magazine on turbine, hydraulic and gear oil specification tests. Refer to these articles for an in-depth coverage of lubricant specification tests and how they can help in the selection of the right quality lubricant.

The following list is a summary of the best practices for maximizing lubricant quality:

  • Utilize specification tests on product data sheets to compare lubricants.
  • Contact OEMs for minimum specification requirements.
  • Set minimum lubricant specifications with suppliers.
  • Set standards on new lubricant deliveries, but be reasonable. During the delivery process, it is difficult to maintain high levels of cleanliness. Most hydraulic oils need to be filtered before use.
  • Utilize certificates of analysis for water content and viscosity on any delivered lubricants.
  • Routinely run more extensive tests with an oil analysis laboratory, to determine if a supplier is meeting minimum requirements.
  • Routinely run more extensive tests with an oil analysis laboratory, to determine if a supplier is meeting minimum requirements.
  • Don’t use price as the main criterion in supplier selection.
  • Establish return criteria in lubricant contracts.

3. Right amount Grease lubrication… 

More is not better. Too much lubricant in a system can be as destructive as not enough.as evidenced by the over-greasing of electric motors, which is a major failure mode. Use the formula in Fig. 1 to help grease rolling element bearings with the correct amount.

0207_fiverights_img4The calculation in Fig. 1 will give you the number of ounces to add to a bearing during greasing. This is especially important with electric motors, as there seems to be a tendency to over-grease. In order to add the correct amount, grease guns need to be calibrated on their delivery of number of shots/ounce. This can be done by using a postage scale to weigh out one ounce of grease. An easier method is to count the number of shots required to fill a 35mm film canister; thatfs approximately one ounce of grease. Once your grease guns have been calibrated, try to use the same grease gun type for a given application. Some newer guns will indicate the amount that is being added.

Oil lubrication… 
Centralized oil systems add the right amount at the right time. This section focuses on having the correct level in oil baths and splash-lubricated gearboxes. Many small pumps are lubricated by oiler baths, as illustrated in Fig. 2. The correct level for a bottle oiler bath should be at the middle of the lowest ball.

0207_fiverights_img6Large pumps and process steam turbines that have journal bearings are often
lubricated with the use of slinger rings, as illustrated in Fig. 3.

The oil level with slinger rings should be set at 1/8″to 3/8″ from the bottom inside edge of the ring. The faster the speed the lower the level should be.

Splash-lubricated gearboxes are very common where both gears and bearings are lubricated. Enough oil needs to be splashed up for cooling and lubrication. Too high an oil level will cause churning that over heats the oil; too low a level will not provide proper oil cooling and lubrication for bearings and gear teeth. Spur helical, bevel and spiral bevel gears are lubricated with the gears dipping into the oil at twice the tooth depth. The OEM will provide information on the correct oil level

Worm gears consist of a steel worm and a bronze wheel with the worm being either above or below the wheel. Fig. 4 0207_fiverights_img5shows a worm below the wheel, where the oil level is normally set just below the worm center line. With the worm above the wheel, as illustrated in Fig. 5, the oil depth ranges from just above the wheel tooth depth to the center line of the wheel. The oil level is dictated by the speed. The higher the speed the lower the oil level to minimize churning.

4. Right place
Once we have selected the right type lubricant and the quantity to add, we need to apply it at the proper location. Adding the wrong oil to a lubrication point is not uncommon. This situation will usually go undetected until a problem occurs. With an oil analysis program, early-stage detection is more likely, thus helping to avoid possible equipment damage.

0207_fiverights_img7

 

All lubrication points should be properly labeled as to the lubricant to be added. Lubricant manufacturers provide lube tags for proper identifi cation of the proper lubricant to be used at the lube point. A typical tag is illustrated in Fig. 6.

It is a good practice to use separate containers for different lubricant types. Mixing lubricants with different additive packages is not recommended. Normally, each lubricant supplier color-codes its tags by lubricant types. In Fig. 6, all of the supplier’s hydraulic oils would have red tags, but they would display different ISO numbers, such as ISO 46 and 68. Containers also should be properly tagged, as should the drums or totes from which the oil is transferred to the container. This will minimize the addition of the wrong oil.

The following summarizes best practices for the addition of lubricant at the right place:

  • Become acquainted with lubrication points on new equipment through the OEM manual.
  • Train personnel on correctly adding lubricants to equipment.
  • Label all equipment lube points with color-coded lube tags obtainable from lubricant suppliers. These tags should note:
    • ISO viscosity
    • Type of lubricant based on color
  • Lube containers should be used for only one type of lubricant and display color-coded tags indicating lubricant type. Ideally, use only one container per lube type and ISO viscosity. Apply tags to all lube containers, including totes and drums.

5. Right time
Greasing…
Once we have established our program with the right type, quality, amount and place, we need to establish proper lubrication intervals. Grease frequencies can be determined by using charts, but the following easy calculation also can be used:

Oil…
The frequency of changing lubricants depends upon the type of system and size of the reservoir. Initial guidance can be obtained from the OEM and should be adjusted based on the environmental conditions

0207_fiverights_img9Small reservoirs (under 50 gallons) in non-circulated systems are often changed on a certain frequency based on OEM recommendations and experience. As an example, small ANSI centrifugal pumps in plants typically hold less than two quarts of oil. Interestingly, one plant may change the oil in such pumps every quarter, while another, using the same type of pumps, will change it every two years.

Environmental conditions dictate oil change frequency. The plant changing its pump oils on a quarterly basis probably has diffi cult conditions leading to water ingression and contamination problems, while the plant changing biannually has much more favorable conditions. Such factors also apply to splashlubricated gearboxes and bath-lubricated systems. To determine the correct change frequency for similar equipment under similar conditions, statistically evaluate the condition of the oil through oil analysis tests. This can provide useful information on establishing change frequency.

0207_fiverights_img10

Change frequency for large systems (over 50 gallons) should be established with oil analysis condition monitoring tests. Two major failure mechanisms for lubricants are contamination (particles/water) and oxidation. Routine visual monitoring of the oil is crucial. Oils that are becoming darker indicate possible oxidation and should be further evaluated. Oils that appear to be hazy or have suspended solids in them indicate excessive contamination and also should be further evaluated.

Oxidation, one of the primary reasons lubricants fail, is temperature-dependent. For every increase in temperature of 18 F degrees, the oxidation rate doubles, which in turn, cuts oil life in half. This is noticeable at temperatures over 140 F. When oils oxidize, they produce sludge, varnish and acids, all of which can cause equipment damage. One very useful test is to monitor the increase in the acid number of a lubricant through oil analysis and to set condemning limits for the oil. Refer to “Proactive Maintenance Practices Through Condition Monitoring Of Used Oils,” an article published in this magazine in 2005. Excessive water contamination can be determined with a Karl Fisher test and particle counts that measure the cleanliness of the oil. Both of these procedures are an integral part of an oil analysis program.

The following summarizes best practices in determining oil change frequencies:0207_fiverights_img11

  • Follow OEM recommendations for change frequency.
  • Set frequencies for small systems, based on environmental conditions and operating temperature. Adjust as conditions change.
  • Periodically evaluate used oil in small systems statistically with oil analysis tests to confi rm correct frequencies.
  • Continuously monitor lubricant visually for any color changes and contamination.
  • Utilize oil analysis condition monitoring tests for large systems to establish lubricant changes.
  • Use higher-priced synthetics, where appropriate, to extend drain intervals, especially under high-operating-temperature conditions.
  • Remember that the cost of changing a lubricant is minimal compared to potential equipment damage and downtime. It’s better to err on the side of changing too frequently.

Conclusion 
Establishing a world-class lubrication program through application of the fi ve rights of lubrication will pay dividends. In the long run, enhanced equipment reliability will result in major bottom-line savings. Establishing the right program requires real planning and work-and the lubricant supplier and OEM should be utilized when needed. The fi rst step is to recognize and promote the importance of a well-designed lubrication program to management. The next step-and the most diffi cult one-is to effectively implement that program.

References

  1. Bannister, Kenneth E., Lubrication for Industry (2nd edition), Industrial Press, 2007
  2. Lansdown, A.R., Lubrication and Lubrication Selection, Mechanical Engineering Publications, 1996
  3. Neale, M.J., Lubrication and Reliability Handbook, Butterworth and Heinemann, 2001

Contributing editor Ray Thibault is based in Cypress (Houston), TX. An STLECertifi ed Lubrication Specialist and Oil Monitoring Analyst, he conducts extensive training in a number of industries. E-mail: rlthibault@msn.com; or telephone: (281) 257-1526.

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