Archive | March, 2008

93

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March 1, 2008
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Problem Solvers

0408_probsolver_cameraCompact IR Technology

Infrared Cameras’ new compact ICI 7320 is roughly the size of a business card. Offering high image sensitivity and clarity for a 320 x 240 radiometric imager, it operates on a single watt of power using a USB connection. IRFlash software sends real-time radiometric data directly to a hard drive or portable device. Available enclosures provide harsh weather and/or environment protection while meeting all meeting NEMA 4-NEMA 9 specifications.

Infrared Cameras, Inc. 
Beaumont, TX

0408_probsolver_lockout

Lockout/Tagout Compliance

Brady’s new 16- page “Complete LOTO Solutions” handbook lays out a straightforward “4-Steps to Compliance” plan for creating an effective energy control program. Each step includes an explanation of OSHA’s basic requirements, and provides information on the related resources Brady has available for successful implementation of your lockout/tagout program.

Brady Corporation 
Milwaukee, WI

Interactive Tool Helps Manage Energy Costs

Dow Corning has launched an interactive Molykote® Energy Savings Calculator. The online tools helps manage rising energy prices and carbon dioxide emissions by identifying energy and cost savings available through lubrication best practices. Users enter the number of motors, gearboxes, pumps, compressors and fans, the kilowatts needed to run them, their efficiency, the hours per day and days per year into the calculator. They are shown potential reductions in kilowatt hours, CO2 emissions and the associated cost savings.

Dow Corning
Midland, MI

0408_probsolver_shaftShaft Seals For Dry Bulk Processing

According to Woodex Bearing, its custom-engineered MECO shaft seals can increase MTBF by a factor of 4 or more over packed glands in dry bulk process equipment. Rotating on a plane perpendicular to a shaft means there is no relative motion between the shaft and seal, and, thus, no shaft abrasion damage. Seal faces are soft, faulttolerant and almost impossible to break. Like all MECO seals, these robust products are available fully-split for quick installation and rebuilds. Accommodating 6mm or more total shaft runout/misalignment, shock loads and thermal shaft growth, they also contain no internal springs to loosen, corrode or break.

Woodex Bearing Company
Georgetown, ME

0408_probsolver_trampCompact Tramp Oil Separator

Master Chemical’s Master Coalescer Jr.™ is a compact and affordable processor of machine tool coolants. Designed for use with water-miscible coolants and parts-washing fluids that reject tramp oils, it is available in both wheeled and stationary models. Requiring minimal maintenance, these units allow for maximum removal of tramp oil, even while they are running.

Master Chemical Corporation 
Perrysburg, OH

0408_probsolver_tank

Tank & Vessel Level Measurement

The Gladiator Smart Admittance Level Switch from Hawk is designed to detect the level of liquid, slurry or powder in a tank or vessel. Designed to operate in tough environments, it measures the capacitance between a probe and the wall of the container. The Gladiator is simple to set up and calibrate, and has excellent temperature stability. Several probe types are available to meet specific application requirements, and all types are resistant to product build-up.

Hawk Measurement Systems 
Melbourne, Australia

0408_probsolvers_bearingsSelf-Lubricating Bearings For Dry & Submerged Jobs

Metallized Carbon Corporation offers Metcar grades M-161 and M-162 mechanical materials, unique carbon/graphite Babbit impregnated products designed to operate where conventional lubricating methods can’t. At temperatures up to 350 F, they are well suited for lubricating in submerged low viscosity fluids such as water and fuels. For dry environments, they provide oil-free lubrication at high temperatures. According to the manufacturer, because these materials are completely homogenous and provide continuous lubrication for their long service life, they are ideal for use in bearings, bearing assemblies and mechanical components operating at elevated temperatures. Bearings made from Metcar are self-lubricating, non-galling, dimensionally stable and have high compressive strength.

Metallized Carbon Corp.
Ossining, NY

0408_probsolvers_lanceNew Jet Lance

Lightweight and ergonomic, the NCG40-286 water jet lance from NLB Corp. offers a 40,000 psi and 60- second cartridge change. A one-finger latch prevents accidental actuation and its patented trigger design allows the operator to immediately dump pressure by simply pushing the trigger forward. The lance also can be used with the company’s Viper 40™ self-rotating head, producing rotating water jet action without compressed air.

NLB Corp. 
Wixom, MI

0408_probsolvers_oilmistCalling All Safety-Conscious Oil Mist Users

Inpro/Seal’s OM 32 oil mist seal contains no ferrous materials that could generate sparking conditions by sealing faces or magnets upon wear and eventual component d e g r a d a t i o n . Made of 100% non-sparking bronze, it does not contain any contact surfaces to heat up due to the combustion of volatile materials. Plus, it puts an end to mist condensation on surrounding structures. If the rolling element, primary bearing fails, the OM 32 acts as an emergency sleeve bearing to prevent shaft-to-housing contact. Improvements to the original design include the ability to work with low base lubricant viscosities and the addition of VBXX™, a proprietary technology that eliminates the ingress of contamination.

Inpro/Seal Company 
Rock Island, IL

0408_probsolvers_airUpgraded Air Management Equipment

F or storage, handling and unloading of commodities, AIRLANCO offers the AIRAUGER™ unloading system for storage, handling and unloading of commodities. It safely and efficiently empties commodities from storage facilities utilizing both pitched flooring and air—without bin entry. Capable of being installed in new or existing storage units, all mechanical equipment is situated outside the bin for added safety and ease of service. The system also provides bin aeration of the stored commodity with the same ductwork and fans used during unloading operations.

AIRLANCO 
Falls City, NE

0408_probsolvers_loggerMulti-Tasking Data Logger

Omega’s battery-powered, 3-axis OM-CP-ULTRASHOCK101- 50-EB shock recorder measures and records temperature, pressure and humidity at the selected reading rates, while recording shock at peak acceleration rates. Compact and portable, features include CE compliance, 60-day battery life and data retrieval via a COM or USB port.

OMEGA Engineering, Inc.
Stamford, CT

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135

6:00 am
March 1, 2008
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Compact, durable, lightweight, economical… This New Speed Reducer Takes On Your Toughest Jobs

0408_solutionspotBaldor has introduced the Dodge MagnaGear XTR, an extra-tough speed reducer that has been engineered to offer maximum reliability and superior performance in especially challenging, high-torque applications. According to the manufacturer, the MagnaGear XTR is ideal for bulk material handling in dirty, dusty, harsh environments. That means mining, aggregate, cement, wood products and grain industries, where these robust new products are well suited for a wide range of applications, including conveyors, bucket elevators, feeders, mills and crushers/breakers.

Putting proven technology to work 
Engineered with proven planetary and helical gear technology, the new MagnaGear XTR line covers a full range of horsepowers, up to 2000 HP. Designed as a global product, the reducers are offered with parallel shaft or right-angle configurations, a solid or hollow shaft output and will initially offer torque capacities up to 920,000 lbin. Incorporating a modular design that allows for multiple mounting configurations, they can be used with a variety of soft-start mechanisms.

Developed to meet or exceed AGMA and international standards, heavy-duty, cast iron units feature carburized, hardened and precision-ground gearing. Tandem HBNR lip seals are standard for extra protection. All bearings exceed AGMA standards for L10 life. All components are power matched for optimum performance at a lower installed cost.

A complete line of engineered accessories are available for MagnaGear XTR, including internal lift-off style backstops, cooling systems, rigid couplings, torque arms, swing base mounts, tunnel housings and baseplates.

Baldor Electric Company 
Fort Smith, AR

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136

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March 1, 2008
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Onboard Pump Intelligence Gives A Timely Heads Up

Kiss unexpected ANSI pump failures good-bye. This industry first is the type of intuitive and efficient early warning system you’ve been wishing for.

0408_solutionspot_2

We all know it. With so few people and so little time to manage and maintain your equipment and processes, your plant’s ANSI pumps simply may not get as much love and attention as your turbines, compressors and higher-ticket pumping equipment. That’s all about to change!

The new i-FRAME from ITT Goulds provides operations personnel, maintenance managers, reliability engineers and technicians—anyone responsible for monitoring and repairing rotating equipment on a 24/7 basis—with early warning of impending trouble so that changes to the process or machine can be made before failure occurs. The unit’s stainless-steel condition monitor (see inset) is nested securely atop the power end to measure critical vibration and temperature readings. Variations that exceed preset parameters will activate the early warning system by displaying flashing red lights—things that are easily recognized during routine walk-arounds.

Great has gotten better 
According to Patrick Prayne, product manager of ITT Goulds ANSI Process Pumps, the company’s Model 3196 is acknowledged to be the most popular process pump in the world. “Now,” he says, “we’ve made it even better. This increased reliability and condition monitoring intelligence gets to the heart of our most important customer requirement—reduced downtime and equipment life cycle cost.”

In addition to the condition monitor built into the pump, the patent-pending i-FRAME incorporates a number of other standard features designed to increase reliability and the life of the pump, including:

  • Premium severe duty thrust bearings that increase fatigue life by 2 to 5 times that of standard bearings.
  • Dual stainless-steel, bronze bearing isolators for improved corrosion resistance and contaminant exclusion.
  • An optimized sump design to improve heat transfer and collect and concentrate contaminants away from the bearings, resulting in longer bearing life.

Model 3196 units with i-Frame power ends also carry a whopping 5-Year Warranty as standard.

Availability
Recognized as a true workhorse in chemical, oil & gas, petrochemical, pulp & paper, and other industrial operations around the globe, the Goulds 3196 comes in 29 different sizes offering a wide range of features for handling challenging applications. According to the manufacturer, its new i-Frame units will be available this April.

ITT Goulds
Seneca Falls, NY

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161

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March 1, 2008
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Taking it to the extreme…Lubes For Severe Environments

0408_techupdateThe places where lubrication is needed aren’t always made to order. Too often, lubricants are required to stand up (and perform without a hitch) under some of the most severe conditions imaginable—extremely hot and cold environments, hazardous surroundings, contaminated areas, etc. The following list reflects companies and products that take care of the critical equipment and processes that must stay up and running in these types of challenging, often remote, situations.

Royal Purple
Most severe-service equipment reliability problems are caused by heat, contamination and/or load. The severity of these conditions impacts lubricant’s ability to adequately lubricate and protect equipment, resulting in premature failure and reduced operating efficiency. Conventional, low-film strength R & O (rust and oxidation inhibited) oils rely almost solely on their viscosity to protect equipment against wear. A new generation of lubricants offers improved oxidation stability to withstand heat and dramatically increased film strength to withstand severe load. Synfilm, from Royal Purple, has become increasingly popular in severe service applications. Synfilm is a long life, high film strength, synthetic lubricant that’s proven to significantly increase the reliability and life of equipment operating in severe conditions.

Royal Purple 
Porter, TX 
www.royal-purple-industrial.com

The Timken Company 
Timken’s Mill Grease is formulated with high VI paraffinic mineral oil, resulting in better oxidation stability than competitor formulas that use low VI naphtenicbase oil. Use this grease when resistance to water washout and performance under broad operating temperatures are absolutely necessary. Design attributes include superior protection against rust and corrosion, including salt spray, and excellent high-temperature properties, including conditions from -40 F to 400 F. The lubricant contains no heavy metals or other environmentally undesirable additives. Timken’s Mill Grease is applicable for steel mills, paper mills, aluminum mills, foundries, cement plants, power generation, off-road applications, mineral processing, offshore rigs and marine applications.

The Timken Company 
Canton, OH
www.timken.com

CITGO Petroleum Corporation 
According to CITGO, its range of synthetics provides exceptional protection for compressors in remote locations, where maintenance and parts replacement demand premium products. CompressorGard PAOs offer superior oxidation and thermal stability for use in rotary vane, rotary screw and centrifugal compressors. The CompressorGard PAGs are recommended for highpressure reciprocating compressors pumping natural gas, hydrogen, helium, CO2 and other polar gases. DE synthetics combine premium diester base stocks with advanced additives for better low-temperature fluidity and thermal conductivity. Compared to conventional lubes, the low vapor pressure of the CompressorGard SS helps reduce oil carryover in a compressed gas stream, and inhibits H2S corrosion. CompressorGard IPG 100 provides increased viscosity at high temperatures, oxidation resistance and good water separation.

CITGO Petroleum Corporation 
Houston, TX
www.citgo.com

Mobil Industrial Lubricants
Mobilgear 600 XP Gear Oil Series is engineered to deliver exceptional, long-lasting wear and corrosion protection for gearboxes, and can help companies become more competitive by raising their productivity. Surpassing the industry’s most demanding specifications, such as Flender BA Table 7300 A, DIN 51517 Part 3 and AGMA 9005 E02, Mobilgear 600 XP helps control micropitting and is designed to significantly reduce the formation of oil degradation by-products that often lead to frequent oil changes.

Mobil Industrial Lubricants 
Fairfax, VA
www.mobilindustrial.com

CRC Industries
CRC’s Extreme Duty Open Gear & Chain Lube is a heavy duty, extreme pressure lubricant recommended for reducing friction and wear in harsh environments. The formula is specially prepared to penetrate pores in metal, with exceptional “stay-put” characteristics. It assures a smooth, long-lasting, economical and effective coating that will not wash or wear off because of harsh weather and will not break down after repeated use. The lube contains Moly and Graphite, providing lubrication and shock protection, preventing scoring and welding of gear teeth. Its black color guides proper coverage, allowing easy touchup. Use CRC Extreme Duty Open Gear & Chain Lube to lubricate open gears, chains, cables or wire ropes. It is ideal for use on quarry and mining equipment, leaf springs, drive chains, screw threads and flexible couplings. It can also be used on racks and pinions, ball and rod mills, trunions, roller gears and winches.

CRC Industries 
Warminster, PA
www.crcindustries.com

ConocoPhillips 
The use of synthetic lubricants has become more widespread in automotive and industrial machinery, partly because of the severe demands imposed on the lubricants by downsizing of oil sumps, generating more power and the more stringent performance requirements established by the OEMs. ConocoPhillips Syncon® & Syndustrial ® synthetic lubricants are commonly used in industrial machinery such as air & gas compressors, aero-derivative turbines, underground mining equipment and gearboxes operating in very cold weather or very high temperature environment. They offer significant advantages over conventional lubricants in terms of low temperature pump ability and easier starts in cold weather, as well as energy savings, superior high temperature protection and longer service intervals.

ConocoPhillips Lubricants 
Houston, TX 
www.conocolubricants.com
www.76lubricants.com
www.phillips66lubricants.com

DuPont 
Designed specifically to perform under harsh conditions and critical chemical service, DuPont™ Krytox® NRT & XHT oils and greases offer an ideal solution to extend equipment life, improve safety and reduce the potential for explosions and fire. Krytox NRT inert lubricants deliver safe, non-reactive, non-flammable lubrication for systems containing LOX, GOX, chlorine and other reactive gasses while extending equipment life. Krytox XHT Extreme High Temperature lubricants perform up to 752 F. From gearboxes, bearings and chains—to seals, actuators, valves, and more—DuPont Krytox NRT & XHT provide unparalleled performance with everyday reliability.

DuPont Performance Lubricants 
Wilmington, DE
www.dupont.com

JET-LUBE, Inc.
JET-LUBE’s industrial 769 Lubricant®, first introduced in 1969, is still delivering high performance in harsh environments. Salt water and salt spray, in particular, are no match for this product. It’s economical, environmentally safe and non-flammable, and it doesn’t evaporate or harden. It contains ashless extreme pressure additives and highly refined lubricating oils that provide superior lubricating protection and anti-wear properties. Additionally, 769 lifts and displaces moisture, while also preventing rust and corrosion. The product is available in a variety of sizes, ranging from 12-oz. aerosol containers to 50-gal. drums.

JET-LUBE, Inc. 
Houston, TX 
www.jetlube.com

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151

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March 1, 2008
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Communications: Partnering For Safety

0707_bannister1

Ken Bannister, Contributing Editor

In 1995, the U.S. National Safety Council published a provocative paper entitled “In Safety, Half Truths Hide the Story.” It stated: “Practically every [safety related] incident is the result of inadequate management action, supervisor and worker training, procedures and work conditions and/or safety rules and policy enforcement.” This reflects the common belief that a safe workplace is most likely one in which management has embraced worker safety as the highest priority.

While worker education and policy enforcement is an absolute requirement to realizing a safe workplace, we cannot dissolve individual accountability when it comes to personal safety. This is apparent when, despite all the safety messages, procedures, meetings, checks, specialized equipment, training, permits, measures and good intent, we still hear about maintenance professionals getting hurt on the job.

A parallel prime non-workplace example can be found with the automobile. Here, the manufacturer has been both legislated and proactive in providing the user with what is arguably the safest environment in the world.

Today’s vehicles are emblazoned with colorcoded safety messages, safety glass, seat belts, front and side air bags, body roll protection, energy-absorbing crumple zones, climate control, traction control, ABS braking systems, warning systems, etc. Yet, we still see an alarming amount of injury and death on the roadways.

Conjectured opinion has placed blame for most automobile accidents on human error caused by distraction. Driver distraction takes many forms, including eating and drinking, primping, listening to loud music, using cell phones, reading and the not-so-obvious distractions such as fatigue, anger, relationship problems and other types of emotional stress, among others.

How often, while driving or performing a task at work, have you found yourself distracted and poorly focused on the task at hand? Unfortunately, stress caused by workloads, relationship problems, poor diets and/or sleep deprivation all can cause distraction and compromise safety. The reality is that we are all partners when it comes to safety. Accordingly, we are responsible for both our own and each other’s safety.

Frame of mind
Safety is a combination of understanding, managed risk, common sense and—above all— frame of mind.

Prehistoric man truly understood the dangers of his environment, as his life very much depended on personal awareness every minute of the day. In today’s world, we are accustomed to “handing over” our safety to others, often ignoring our intuition, and rarely seeking to truly understand the dangers that accompany us every minute. Changing one’s frame of mind begins when we actively seek understanding about the dangers within our working environment.

With management providing the safety tools and training, it is up to us as individuals to make that training personal. Many individuals work in potentially hazardous environments; risk is managed through understanding consequence of failure and being competent in our response to those failures. Thus, making an effort to fully comprehend your work environment and method of manufacturing or process deliverable is crucial to understanding and managing risks you face should a failure occur.

Stay well and aware
Learn to recognize both normal and abnormal equipment behavior. Check out the Material Safety Data Sheets of both production and maintenance materials. Know what you are handling. Being trained in confined space management is futile if you cannot personally recognize a true or marginal confined space within your workplace— without an identification signpost. Knowing how to operate an emergency wash station is wasted, if you don’t know where the emergency wash stations are located.

Managing risk is all about marrying understanding, knowledge and common sense. However, developing and using a common sense approach to managing stressful and dangerous situations can be difficult to achieve when an individual’s frame of mind is distracted and unable to focus. To combat this, more and more companies now recognize that wellness—or an individual’s good mental and physical health—is equally important as a safety-driven workplace culture in providing enhanced employee self-esteem and a clear frame of mind. In turn, this all translates into a much healthier, safer and more productive workforce.

Forward-thinking companies are now providing opportunity for their employees to elevate their personal fitness levels by offering differing workplace programs that include gymnasium sports, field sports, meditation and healthier, lighter fare in their company cafeterias. Mental health programs are rapidly on the rise and manifest themselves in workplace day care programs, personal counseling programs, education completion programs, generalinterest training programs, etc. These types of company-sponsored or sanctioned initiatives are all clearly aimed at cutting down the stress in employees’ daily lives by significantly reducing distractions and growing healthier, safer workplace environments.

Be careful out there
Subscribing to a safer and healthier attitude toward work and life in general is all about developing and maintaining a true connection with your own self. Health and safety truly is a personal issue, connecting each and every one of us as partners. MT


Ken Bannister is lead partner and principal consultant for Engtech Industries, Inc. Telephone: (519) 469-9173; e-mail: kbannister@engtechindustries. com

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March 1, 2008
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Ensuring Reliability And Safety Of Your Process Cranes

Are you investing too much, too little or too late in your crane maintenance efforts? An in-depth reliability survey can be invaluable in helping determine what level of this maintenance is optimal for your operations.

It’s widely known that investing effectively in crane maintenance can help reduce the risk of safety and environmental incidents, breakdowns, loss of production and premature equipment failure. Unfortunately, what level of investment is “optimal” is not as well known. There are various levels of crane maintenance that dictate what value, benefits and return a company can expect on their investment. The optimal level must not only remediate risk factors but also demonstrate a measurable return on investment.

0308_cranes_21

Cranes represent a substantial investment for a company. Thus, determining the right level of maintenance required to maximize that investment should be a high priority. This is especially important for companies that depend on cranes as a part of their process.

When a crane becomes an integral part of a production process, it is called a “process crane.” Since process cranes are designed for round-the-clock use, they call for maximum reliability. They must be able to answer the most stringent performance requirements, including: automation, highly demanding duty cycles, difficult operating environments, high operating speeds and special control systems. The cost of downtime for a process crane can easily exceed $1 million US per day. Repairing the equipment after it breaks (i.e., corrective maintenance) is simply not enough. The optimal solution is to prevent the breakdown from occurring in the first place.

Optimal maintenance of process cranes can significantly reduce overall operating costs associated with downtime, etc., while boosting productivity. This is considered a proactive maintenance approach. In order to truly develop a proactive maintenance strategy, companies must conduct an in-depth crane reliability survey to gain the insights needed to develop their plans. Systematic and exhaustive surveys of this type will provide the facts needed to develop a smart strategy. In-depth crane reliability surveys also generate the information needed to enhance safety and mitigate issues, improve performance and reliability and extend the service life of a company’s process cranes.

Enhancing safety and mitigating issues
An in-depth crane reliability survey relies on the use of advanced diagnostic tools that penetrate deep into equipment and uncover problems that are undetectable by standard equipment inspections. Addressing those problems in advance prevents injuries from occurring and presents tremendous savings in injury-related costs.

Improving performance and reliability
A crane reliability survey provides a roadmap for improving equipment performance and reliability. Knowing what repairs are needed in advance allows a company to prioritize its maintenance activities and schedule the work so as to maximize productivity and increase uptime over the life cycle of its equipment. This not only helps prevent unnecessary production downtime— it saves money.

Extending equipment service life
A crane reliability survey also can help extend the service life of equipment by providing a guide for preventive maintenance, which, in turn, helps reduce capital investment costs. Knowing when to anticipate repairs allows a company to forecast expenses and put them into its budget for improved cash flow. This will help to avoid the unpleasant surprise of a sudden breakdown and the unexpected expense of the repair or replacement of their crane, which could lead to a loss in production revenue.

Conducting a crane reliability survey
A crane reliability survey is a very sophisticated undertaking. Every crane is different. Therefore, it’s important to study documentation, interview users and conduct in-depth analyses using advanced instruments that detect potential problems other inspections miss. A crane reliability survey should include four key modules: the CORE inspection, structures and working conditions, components and the maintenance assessment.

CORE inspection and analysis…
The aim of the CORE Inspection is to calculate the crane’s Safe Working Period—a time period assessed in which the operating characteristics of the crane (running speeds, acceleration, and deceleration) are suitable to the current use of the crane. During this phase, all crane information should be collected. It is important to become familiar with the crane through a review of all available documentation—reports and notes from past inspections and photographs of the crane and its parts. It also is important to gather information regarding the service history and current condition of the crane.

0308_cranes_3Next, it is important to conduct interviews to fully understand the usage and performance of the device. Any machine is best known by its primary operators. In some cases, the operator may need to adjust usage behavior and habits in order to extend the service life of the machine. Lastly, a detailed inspection is required. A field inspection should include gathering information on the overall crane condition. The crane should be inspected and the service life analyzed.

Structures and working conditions…
This study provides an overall analysis of the crane’s condition by evaluating the operating environment, the present state of the power supply, the alignment of the crane structure, its associated runways and the steel structures of the equipment. A series of four exhaustive analyses should be performed.

  1. An ambient conditions analysis ascertains the operating conditions of the equipment, in which temperature, humidity and dust of operating equipment are analyzed. In addition, it is important to define the corrosive effects of the environment, using both tests and visual inspections.
  2. A power supply analysis can detect potential problems related to the supply voltage of a crane. Common problems may include: a too high or too low voltage level, voltage dips, swells or interrupts.
  3. It also is essential to conduct a geometric analysis to study the runway where the equipment is located. The condition of the runway strongly influences how well a crane moves on its rails, affecting the usability and lifetime of the traveling machinery units. It’s important to inspect the permitted geometrical tolerances: measuring, visually inspecting the rails and their fixings and comparing them to original installation drawings.
  4. During the final stage in this phase, it is crucial to conduct a steel structure analysis to scrutinize each individual part for deficiencies in physical condition and assess structural safety.

Components…
The component analysis is a specific, detailed assessment of the present condition of the crane’s electrical components— all motors, gearboxes, hook block assemblies and the wire rope and its revving component. It is important to evaluate the risks that can lead to production loss due to component failure and explore options to minimize such occurrences.

An electrical component analysis will help to determine the condition of crane electrification. To improve reliability, there are many objects in the electrification that require monitoring. Furthermore, a motor analysis is necessary to determine the current condition of the motors on the crane.

The wire rope is one of the most critical parts of the hoisting machinery. The rope is stressed by tension, compression and bending during lifting cycles. Along with visual inspection, it is imperative to perform an advanced, non-destructive assessment with a rope tester.

Determining the condition of the crane’s hoisting and traveling gear is critical. Gears are normally designed so that the gear surfaces wear clearly and the load-carrying capacity is not lost—assuming that the gear case is maintained correctly. The purpose of the gear analysis is to define the current status of the gear in order to reduce the risk of gear failure.

Based on international standards, the hook and hook block also should be examined. The hook is used during every lift cycle and can be subjected to conditions that will produce mechanical stresses.

Maintenance and reliability…
During this phase, evaluate the overall maintenance of the crane by analyzing the reliability of the crane. The purpose of this analysis is to define the reliability of the crane and identify the most critical components that could cause downtime.

The reliability analysis should include a Life Cycle Assessment (LCA) environmental impact analysis, a spare parts analysis, and a cost analysis. The Life Cycle Assessment (LCA) determines the total environmental impact the crane will produce during its operating lifetime. This analysis includes emissions to air and water.

Spare part availability can cause an increased threat to productivity. The purpose of the spare parts analysis is to determine the parts that are critical and that should be readily available. The analysis also considers the suitable requirements of a storage location and estimates the value of the inventory of spare parts.

Next, evaluate all costs associated with the operation of the crane in a cost analysis. This analysis documents the company losses—time and monetary—as a result of inefficient equipment. Examine maintenance and operation records from a two-year span to determine the duration and frequency of a crane’s downtime and its overall impact on the production line. During this phase, analyze maintenance costs, production and quality losses. Moreover, a complete audit of the current maintenance situation of the company’s material handling equipment is recommended.

A company can perform its own crane reliability surveys or obtain them through outside sources (see Sidebar). Whatever approach you take, the point is to help you determine that “optimal” level of maintenance that will keep your process cranes up and running as scheduled—safely, reliably and cost-effectively. MT


Mike Williams is vice president of Service with Konecranes Americas. Telephone: (937) 525-5560; e-mail: mike.williams@ us.konecranes.com

About Konecranes

Products and services backed by 80+ years of experience

Konecranes designs, manufactures and services standard and heavy lifting equipment for multiple industries around the globe. Operating in 41 countries, it maintains more lifting equipment than any other company in the world. It also is a leader in the development of specific industry requirements and regulations for reliability and safety of overhead lifting equipment.

Konecranes is able to assemble highly-experienced teams to conduct Crane Reliability Surveys (CRS) on all makes and models of cranes. Each Konecranes CRS team is composed of technicians and specialists. CRS results are presented in a comprehensive, yet easy-to-read report that includes recommendations for future action. After the CRS, the company will understand the crane’s current operating capacity, know how to plan ahead and be able to forecast expenses in order to better manage its maintenance budget.

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148

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March 1, 2008
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Solution Spotlight: New Speed Reducer Takes On Your Toughest Jobs

B0308_solutionspotlight1aldor has introduced the new Dodge MagnaGear XTR, an extra-tough speed reducer that has been engineered to offer maximum reliability and superior performance in especially challenging, high-torque applications. According to the manufacturer, the MagnaGear XTR is ideal for bulk material handling in dirty, dusty, harsh environments. That means mining, aggregate, cement, wood products and grain industries, where these robust new products are well suited for a wide range of applications, including conveyors, bucket elevators, crushers/breakers, feeders and mills.

Putting proven technology to work
Engineered with proven planetary and helical gear technology, the new MagnaGear XTR line covers a full range of horsepowers, up to 2000 HP. Designed as a global product, the reducers are offered with parallel shaft or right-angle configurations, a solid or hollow shaft output and will initially offer torque capacities up to 920,000 lb-in. Incorporating a modular design that allows for multiple mounting configurations, they can be used with a variety of soft-start mechanisms.

Developed to meet or exceed AGMA and international standards, heavyduty, cast iron units feature carburized, hardened and precision-ground gearing. Tandem HBNR lip seals are standard for extra protection. All bearings exceed AGMA standards for L10 life. All components are power matched for optimum performance at a lower installed cost.

A complete line of engineered accessories are available for MagnaGear XTR, including internal lift-off style backstops, cooling systems, rigid couplings, torque arms, swing base mounts, tunnel housings and baseplate. MT

Baldor Electric Company
Fort Smith, AR

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742

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March 1, 2008
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Part IV. Non-OEM Pump Rebuild Shops: Case Studies

0308_pumprebuild_fig11How competent is competent? More importantly, how much might it actually cost your operations if you were to entrust your pumps to the wrong shop?

This article is the last installment in a four-part series based on a presentation delivered at the 2007 NPRA Reliability & Maintenance Conference in Houston, TX. As in the previous installments, (which ran in the July and September 2007 and February 2008), the authors discuss how to distinguish competent pump repair operations.

In this fourth and concluding part in our series on non-OEM pump repair facilities, we discuss two actual case studies. As you read on, please recall that we coined the acronym “CPRS” to convey the term Competent Pump Repair Shop.

Repair case study #1:
Two IR Type J4x 15 lean amine pumps The first of our two case studies concerns the repair of two IR Type J4 x 15 radially split, double suction, betweenbearing pumps purchased in 1982 for lean amine service. Figs. 1 through 3 provide specifics.

The pumps were to be repaired using new 316 stainless steel casings and heads furnished to a CPRS by the refinery client. The client had bought these parts from the “current” OEM—a successor company to the initial OEM. While one pump was being repaired, the other pump remained in service, operating without a spare. However, the new casings and heads required considerable rework before they could be used. This rework included:

  1. Sleeving and re-machining an oversize stuffing box bore;
  2. Re-machining the two spiral wound gasket faces;
  3. Weld-repairing a sand inclusion on a stuffing box face;
  4. Re-facing the stuffing box faces to remove steps caused by the milling operation;
  5. Re-machining two stuffing box bores that had been damaged so that the seal gland pilot would not engage.
0308_pumprebuild_fig2_31

Based on the location of the bolt holes in the bearing housing mounting flanges, neither cast casing was symmetrical with respect to its shaft centerline. The new casings and covers also were drilled for the bearing housing alignment dowel pins. The casing and head for the second pump were returned to the “current” OEM after a pinhole leak was discovered while air testing the mechanical seals. The second pump was returned to the refinery with the original carbon steel casing and head.

Repair case study #2: Worthington Type 8 UZDL21 multistage ash sluice pump
A Worthington Type 8 UZDL21 two-stage pump from a power plant was received by this CPRS in 2006. It was disassembled and inspected and the names of the personnel involved in this work were recorded in the evaluation. By recording these names, the owner-operator (“client”) of the pump was able to ascertain the experience levels of staff assigned to dismantling and inspection duties. Client representatives were in attendance for the inspection and met with CPRS personnel. A comprehensive Inspection Report & Repair Proposal was generated, submitted and quickly approved by the client. Repairs were started without delay.

The purpose of an Inspection Report and Repair Proposal is to evaluate repair options and/or design changes that may (or may not) be included in the repair plan, but which the examining engineer believes could increase the run time of the pump. The following design changes were implemented in this repair sequence:

  1. Wear ring configurations were changed from “saw tooth” to “smooth.”
  2. All wear rings were coated with 88-12 tungsten carbide, 0.020” thick.
  3. Thrust bearings were changed from MRC 8317 AB to SKF 7317 BEGAM.
  4. Oil flinger ring diameters were increased from 7” to 7.50”.
  5. An appropriately sized oil drain hole was added in the bearing housing bore at the 6 o’clock position
  6. Bolt-in bearing housing oil dams were eliminated.
  7. The bearing housing oil level was changed from its previous level to an appropriate new level.

Based on the condition of the ash sluice pump and conversations with the client, the abrasive action of the ash sluice mixture limited the run time of the 316 stainless steel pumps to between 12 and 18 months. Based on the client’s information package, this particular pump had operated for about 18 months and was taken out of service due to a catastrophic thrust bearing failure. In turn, this failure caused rubbing of the 2nd stage impeller back shroud to the casing and the shaft-to-thrust-end cover. The direction of thrust was away from the coupling and opposite to the preferred direction for the SKF/MRC “PumPac 8317 AB” bearing. The wear ring clearances were abnormally large and there was no evidence of oil in the thrust bearing or in its housing. Other damaged components included:

  1. Coupling end sleeve nut;
  2. Oil slinger rings;
  3. Radial bearing; and
  4. Cracked first stage impeller shroud.

The most probable and primary cause of the failure was (initially) determined to have been lack of lubrication to the thrust bearings. Nevertheless, the failed radial bearing showed a slight hint that there had, in fact, been oil in its housing. The CPRS examining engineer realized that the pump could not have operated for 18 months without oil in the bearing housings. Hence, lack of oil was judged a maintenance issue that would have to be addressed at the plant.

But, the examining engineer also believed that a thrust bearing failure could have occurred—even if the housings did have the required amount of oil. He knew that Type 8317 AB bearings, as had been installed, are designed to carry axial thrust toward the coupling. Calculations were made indicating that, with normal running clearances, the direction of thrust would be toward the coupling.

From common pump experience, the CPRS reasoned that wear ring clearances become larger with time; the direction of axial thrust then reverses. Further calculations demonstrated that if the pressure on the backside of the second stage impeller is 17-psi lower than on the front shroud, the axial thrust force will be approximately 3000 lbs away from the coupling. A 17-psi reduction in pressure can occur due to excessive leakage across the balance drum wear ring to the first stage impeller suction chamber. To overcome the thrust reversal problem, two recommendations were more closely evaluated by the CPRS:

  1. Reducing the wear rate of the rings and bushings; and
  2. Increasing the axial thrust capacity of the pump away from the coupling.

Comments on wear rate of rings and bushings…
The informative input from a CPRS explains why a certain course of action is recommended. The report generated during this case study discussed the following items:

1. Flushing One method of reducing the wear rate of the rings and bushings would be to reduce the concentration of abrasive matter forced through the running clearances. Flushing the rings and bushings with clean water would accomplish this. (Slurry pumps used in refineries are often designed with this feature.) This option was briefly discussed but did not seem to be feasible due to the lack of high-pressure clean water at or near these ash sluice pumps. Low-pressure water is available for bearing housing cooling and mechanical seal flushing. If this option were to be pursued, it would be necessary to determine the flow rate and pressure of the water needed so that a booster pump could be selected and the economics of the system could be evaluated.

Another source of flush water that might be investigated would utilize separators to remove fly ash from a small side stream of the pump’s discharge. However, the maintenance cost associated with separator wear might make this option uneconomical.

2. Ring and bushing geometry The CPRS now considered various popular wear ring configurations. The examining CPRS engineer believed that the pump was last repaired with “saw tooth” type rotating rings and smooth stationary rings and bushings. For the same running clearance and differential pressure per length of seal, this style has the lowest leakage rate. The “saw tooth” geometry disrupts the flow causing high turbulence and thus increases the friction coefficient. During the inspection process it was noted that the rotating wear rings for this pump were oriented so that the direction of flow was opposite to normal. This would most likely cause the wear rings to become less efficient— to have higher leakage rates. In an abrasive-laden ash sluice service the saw-tooth wear ring profiles, stationary casing wear rings and balance drum bushings would show wear. The disassembled pump showed this to be the case. The outside diameter of the 300-series stainless steel impeller wear rings had a hard surface coating, but the inside diameters of the 300-series stainless steel case wear rings and balance drum bushing were soft. It was assumed that the stationary wear parts supplied by the client had a hard surface coating but that it had worn away.

This is where experience helps. The CPRS had recently repaired a multistage pump in coke cutting (abrasive) service. In this instance, the stationary wear rings and bushings incorporated “saw tooth” geometry and the rotating rings were smooth. The impeller wear surfaces had been overlayed with Stellite 6 (42 RC) and the stationary wear rings and bushings were made from 440 C material (48/52 RC). When, after three months of service, the pump was shut down due to a sleeve bearing failure caused by insuffi- cient oil, it was discovered that the smooth cylindrical wear surfaces on the impeller had become grooved due to the abrasive coke fines.

Based on these two experiences (and notice how the CPRS uses what it learns), the lead examining engineer believed that the “saw tooth” grooves trap and, therefore, locally increase abrasive particles. This then causes greatly accelerated wear. The trapped abrasive particles can originate from the pumpage and from the worn hard-coated surfaces. High turbulence created by the “saw tooth” geometry also increases the wear rate.

In an effort to reduce the rate of wear on the inside surface of the case wear rings and balance drum bushing, the lead engineer recommended changing to the normal smooth ring configuration traditionally used in pumps. This would reduce the impact angle of the abrasive mixture to zero, eliminate much of the turbulence and reduce the high local concentration of abrasives caused by groove trapping. The plain cylindrical surfaces also would be simpler to coat and, accordingly, have a higher bond strength.

0308_pumprebuild_tab11

Hard surface coating…
The center stage bushing, impeller, case and balance drum wear rings were to be coated with 0.020” of 88-12 tungsten carbide (88% tungsten carbide, 12% cobalt) using the HVOF process. Having access to a good reference library, the CPRS knew this coating (70-72 RC) had been recommended in the Proceedings of the 9th International Pump Symposium (“Evaluation of Coatings for Abrasive Service”) for slurry services. Running clearances were being increased over API-610 minimum standards to compensate for the reportedly low galling resistance associated with making both the rotating and stationary wear parts from 88-12 tungsten carbide. The design and “as built” running clearances are shown in Table I.

Bearing load capacity issues: thrust direction away from coupling…
When it was received at the CPRS facility, the ash sluice pump was found to be fitted with MRC (SKF) 8317 AB PumPac thrust bearings oriented for axial thrust toward the coupling. With the cracked thrust bearing end cover and worn back shroud of the second stage impeller, it was obvious that the thrust direction had reversed.

History is of interest here. PumPac bearings were developed in the mid 1980s to overcome ball skidding in heavyduty applications where the thrust load is in one direction only [Ref. 1]. Ball skidding becomes a more significant problem as bearing size and operating speed increase. At nDm (rpm “n” times mean diameter “Dm”) values below 250,000, there is little risk of ball skidding. (This ash sluice pump with an operating speed of 1785 rpm and a mean bearing diameter of (85 + 180)/2 or 132.5 mm has an nDm value of 236,513.)

0308_pumprebuild_tab21Assuming over the life of the ash sluice pump that the axial thrust load changed direction, a pair of lightly preloaded 40° angular contact bearings would represent a better bearing selection. Nonetheless, to evaluate the improvement in L10 life, calculations were performed for the existing MRC 8317 AB PumPac bearing set and for a more conventionally applied SKF 7317 BEGAM bearing set. PumPac life calculations were performed by one of the bearing manufacturer’s application engineers. His calculations were based on an axial thrust load of +/- 3000 lbs and radial loads of 167 and 250 lbs. They demonstrated that the values used by the CPRS for bearing life estimates were in the right league (see Table II, as follows). Again, in essence, this situation shows what happens when a CPRS facility involves competent suppliers of pump components in cooperative analyses: The pump user benefits.

The calculations assumed clean ISO VG 32 oil operating at approximately 160 F [Ref. 2]. It appeared, with the original design, that the oil lubricating both the radial and thrust bearings was trapped in its own sump with the oil level above the center of the lowermost ball. Consequently, the oil level in the original bearing sump was being controlled by the two ½” diameter radial drain holes shown in Fig. 4. By eliminating the bolted-in dams in each bearing housing, the bearing balls would no longer be submerged in the oil and churning would be reduced. The temperature rise would be less and the bearings would run cooler.

The CPRS opted for a larger diameter flinger (7.50” instead of 7”), which now makes it possible for the outside diameter of the flinger to be submerged in 0.25” of oil. A 3/8” diameter third drain hole was added to the bearing bore at the 6 o’clock position to drain oil from the cavity between the inboard bearing covers and the bearings. The inboard covers were notched at that position to provide an unobstructed opening to the drain holes. Again, these reflect small, but important, experience-based changes with major beneficial impact on uptime of the pump [Ref. 3].

The CPRS calculated hydraulic thrust generation (in the axial direction) based on the following assumptions:

  1. The first stage double suction impeller is axially balanced.
  2. The back hub of the second stage impeller is essentially the same diameter as the balance drum wear ring, but has neither bushing nor case wear rings.
  3. The head vs. capacity curve for each impeller is similar to the United L-10×23 TC proposal curves.
  4. The specific gravity of an ash sluice mixture is 1.0.
  5. Differential pressure at zero flow is 260 psi, at BEP it is 220 psi.
  6. Each stuffing box is at or near suction pressure.
  7. The pressure distribution on each impeller shroud is equal and has an average value of 0.75 times the pump differential head.
  8. The impeller eye side ring diameter is 11.75”, the shaft diameter is 3.937” and the spacer sleeve diameter is 4.937”. 9. Because suction pressure acts throughout the pump, its effect does not influence the axial thrust and is taken as zero to simplify calculations.

At this point, the CPRS engineer listed his assumptions and submitted detailed calculations. At zero flow and P = 260 psi, the calculations corroborated his assumptions, yielding T = 3604 lbs toward the coupling. Similarly, at BEP and P = 220 psi, the calculations indicated thrust T = 3049 lbs toward the coupling.

While we elected to omit further details, the radial bearing loads were investigated in a similar manner. The message, once again, is that one should select a CPRS that will support its recommendations by readily providing the client with every relevant calculation or evaluation [Refs. 4 through 8].

Furthermore, some pump issues deserve to be tackled just as one would approach a new design. The effects of operation with worn running clearances must be considered; with wide-open clearances, only the anti-friction bearings will carry the radial loads [Ref. 9].

CPRS personnel also know that bearing life is reduced by incorrect bearing-to-shaft fits. Therefore, and in this example, relevant dimensions were recorded. Table III shows the bearing vs. shaft interference fits associated with the ash sluice pump. (Note that “T” stands for “tight.”)

Considering the cracked first stage impeller shroud…
As identified in an Inspection Report and Repair Proposal issued by the CPRS, the outside diameter of the outboard shroud on the first stage double suction impeller was cracked at three locations. Each crack occurred adjacent to a discharge vane tip. These types of cracks are common, especially on impellers that have accrued relatively long run times [Ref. 10]. The CPRS knows this and will not try to sell new impellers where none are needed.

Cracking failures usually result from fatigue associated with pressure pulsations caused by the impeller vanes passing the casing volute tips. The magnitude of these pressure pulsations decreases with the clearance [generally called “B” gap, Ref. 11] between the impeller and volute vane tips. The first stage impeller had a “B” gap that met the API-610 criteria—an important reassurance.

Another, less common, cause of shroud cracking is found on impellers having a natural frequency coincident with a multiple of the operating speed, most frequently the vane passing frequencies. With a 5-vane impeller and two volutes, the pressure pulsations occur at 5 and 10 times running speed of 8900 cpm (148 Hz) and 17,800 cpm (297 Hz). Thus, the natural frequencies of the damaged impeller were measured experimentally using an accelerometer and hammer and the results of this “ring test” cataloged. The lowest natural frequency above running speed was found to be about 658 Hz (22 times running speed).

No conclusive root cause for the cracked shroud was found. The impeller was weld-repaired, re-machined and rebalanced. The shrouds were not thickened as proposed in the original repair scope. The message here: CPRS facilities and their staffs apply scientific principles and analyses every step of the way. (Note: Recent publications, including several “Proceedings of the Texas A&M International Pump Users Symposium,” have shown that new pumps suffering from different resonance phenomena have, on occasion, been delivered and put into service. So, in the case of this ash sluice pump, the testing done by the CPRS was justified, as was deviating from the original repair scope.)

At the conclusion of its work, the CPRS recapitulated and documented the repairs by restating problems and observations, and by again highlighting solutions that were both merely considered and actually implemented. It was a very thorough undertaking, much like this fourpart series, whose purpose, among other things, has been to alert you, the pump user, to the following very important fact:

As denoted by the acronym “CPRS,” a truly Competent Pump Repair Shop, be it OEM or otherwise, will provide considerable value to you and your organization through its experience-driven and highly cooperative efforts. Choose wisely when it comes to entrusting your pumps to others. MT


Regular contributor Heinz Bloch is well-known to Maintenance Technology readers. 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 Jim Steiger is senior aftermarket engineer with HydroAire, Inc., in Chicago, IL. Telephone: (312) 804-3694. Robert Bluse is president of Pump Services Consulting, in Golden, CO. Telephone: (303) 916-5032.

References used in this series
  1. Bloch, Heinz P. and Alan Budris, Pump User’s Handbook: Life Extension, (2006) Fairmont Publishing Company, Lilburn, GA, 2nd, Revised Edition, ISBN 0-88173-517-5
  2. Bloch, Heinz P. and Claire Soares, Process Plant Machinery for Chemical Engineers, (1998) Butterworth-Heinemann, Woburn, MA, 2nd, Revised Edition, ISBN 0-7506-7081-9
  3. Bloch, Heinz P., “Twelve Equipment Reliability Enhancements with 10:1 Payback”, Presentation/Paper No. RCM- 05-82, NPRA Reliability & Maintenance Conference, New Orleans, LA, May 2005
  4. Bloch, Heinz P., “High Performance Polymers as Wear Components in Fluid Machinery,” World Pumps, November, 2005
  5. Bloch, Heinz P. and Fred Geitner, Major Process Equipment Maintenance and Repair, (2006) Gulf Publishing Company, Houston, TX, 2nd Edition, ISBN 0-88415-663-X
  6. Bloch, Heinz P., “How to Select a Centrifugal Pump Vendor,” Hydrocarbon Processing, June 1978
  7. Bloch, Heinz P., “How to Buy a Better Pump,” Hydrocarbon Processing, January 1982
  8. Bloch, Heinz P., “Implementing And Practicing Reliability Engineering,” ASME Energy Conference, Houston, TX, January 1996
  9. Bloch, Heinz P., Machinery Reliability Improvement, Gulf Publishing Company, Houston, TX, 3rd Edition (1998) ISBN 0-88415-661-3
  10. Bloch, Heinz P. and Fred Geitner, Machinery Failure Analysis and Troubleshooting, (1997) Gulf Publishing Company, Houston, TX, 3rd Edition, ISBN 0-88415-663-1
  11. Dufour, John W., and William E. Nelson, Centrifugal Pump Sourcebook, (1993) McGraw-Hill, New York, NY, ISBN 0-07-018033-4
About Hydro

All photos in this and other articles in this series were taken by professional photographer Stephen J. Carrera, and used courtesy of Hydro, Inc. Founded in 1969 and headquartered in Chicago, IL, Hydro Inc. is the largest independent pump rebuilder in North America, providing support for industrial, municipal and power generation plants around the world.

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