When it comes to modern concepts in the field of lubrication and applied tribology, many users these days are far more sophisticated than those who are designing and building the machines they operate. This lack of sophistication by original equipment manufacturers (OEMs) is very evident when you see what’s not included with the sale of new machinery. One could assume that what’s missing from the machine and its documentation is functionally missing from the knowledge and awareness of the engineers and builders of this equipment. Ignorance is not bliss. The same is true for complacency.

Every link in the chain must be equally strong in order for
the chain’s full length to bear the load.

Reliability needs to have shared responsibility. It must be fixed in the DNA of the machine as well as in the minds of operators and maintainers. It’s like a reliability chain; every link in the chain must be equally strong in order for the chain’s full length to bear the load. Machinery Lubrication magazine is primarily devoted to advanced concepts in lubrication from a user’s perspective, more specifically lubrication-enabled reliability. Users not only have a significant influence on machine reliability during operation but also by what is being done (or not done) by equipment builders to “ready” machines for optimum reliability. They want the machine’s design to have an implanted genetic code that enables reliability.

Users define what’s expected from OEMs and the machines they deliver. Of course, meeting the minimum required operating performance is a basic need of every machine, but prolonged sustainability of that performance is also important. This is not simply a matter of quality manufacturing to a design specification in order to avoid defects. From the standpoint of reliability, it’s more about including design features that have little to do with the machine’s functional performance. At first, this may seem unnecessary and wasteful, but when viewed over a timespan of several years, these “extra features” could translate to huge financial benefits.

Reliability Readiness

In sum, OEMs can achieve machine reliability in the following ways (used collectively):

  • Design for functional robustness (functional design, material selection, lab and field testing)
  • Design for optimum maintainability by the user (ease and effectiveness)
  • Quality manufacturing to reduce defects and other anomalies (e.g., Six Sigma)
  • Provide a documented equipment maintenance plan (EMP) (see sidebar on page 3)
  • Training and education of field-service technicians, operators and maintainers to execute the EMP

Developing Reliability Readiness

Investments in machine reliability should be purposeful. Certainly, there will be costs and even risks associated with reliability initiatives. You aren’t trying to maximize reliability but rather optimize it in the context of the user organization. OEMs must be keenly aware of how their machines will be deployed, the operating environment and the minimum needs for reliability. Ideally, they should follow these steps:

  • Determine the overall machine criticality. This process weighs both the probability of failure and the consequences of failure. For more information on quantifying machine criticality, see A New Look at Criticality Analysis for Machinery Lubrication.
  • Rank the most likely failure modes. This is often done using failure modes effects analysis (FMEA). If you don’t know how the machine is likely to fail, you won’t know how to control it. Criticality defines the risk, while FMEA reveals the de-risking opportunities that bring focus and strategy to reliability.
  • Based on criticality and FMEA, develop the specific attributes of the optimum reference state (ORS). As described previously in Machinery Lubrication magazine, the ORS is defined as the prescribed state of machine configuration, operating conditions and maintenance activities required to achieve and sustain specific reliability objectives. In the context of this article, the ORS defines the need for equipment modifications and accessories that optimize the state of lubrication.

While this is the critical beginning of the reliability life cycle, there are many stages that follow to the end of the machine’s life. These stages are described at Reliability Engineers: The Holistic Physicians of Machine Care. Again, this article addresses only the first design stage.

Topics for a Machine Lubrication Manual

  • Detailed and illustrated lubrication procedures (oil change, grease change, grease addition, oil top-up, etc.)
  • Detailed and illustrated flushing procedures and listing of suitable fluids for flushing
  • Oil change interval/regrease interval
  • List of all lube points
  • Recommended lubricants (performance specification) for all lube points and operating conditions (speeds, loads, etc.)
  • Brand/type cross-reference for all lubricants
  • Equipment storage protection practices/products, including the use of fogging agents, shaft extension sprays, breathers and vapor-phase rust inhibitors
  • Contamination control guidelines including target cleanliness/dryness needs
  • Run-in procedures for gears and similar equipment
  • Seal compatibility information for system lubricants and other fluids
  • Frequency and procedural information for all necessary PMs and inspections
  • Comprehensive oil analysis and other condition-based maintenance guidelines

Designing for Maintainability

Maintainability is typically defined as the ease, economy, safety and accuracy with which the necessary maintenance of a machine can be effectively undertaken. When machines are designed and built for optimized maintainability, many benefits are realized including:

  • Increased reliability
  • Lower overall costs of enabling reliability
  • Decreased time to complete maintenance tasks
  • Fewer maintenance errors
  • Reduced maintenance injuries
  • Less training required to perform tasks
  • Improved troubleshooting effectiveness

In seeking lubrication-enabled reliability (LER), the vast majority of the opportunity comes from paying close attention to the “Big Four.” These are vital attributes to the optimum reference state needed to achieve lubrication excellence. The “Big Four” individually and collectively influence the state of lubrication and are largely controllable by machinery maintainers, especially if a machine is designed and built for optimum maintainability. The “Big Four” are:

  • Correct lubricant in use (meets reliability objectives)
  • Stabilized lubricant health (physical and chemical properties)
  • Contamination control
  • Adequate and sustained lubricant level/supply

While it may seem to be an oversimplification to reduce lubrication excellence to just four basic objectives, as a practical matter, not much else is required. See the tables on pages 2, 4 and 5 to learn how machine maintainability can be applied in the context of the Big Four.

Role of Buyers/Purchasing

Before buying new machinery, an engineering specification should be carefully and thoroughly developed. Engineers charged with writing these specifications should be educated on modern concepts in machinery lubrication. Simply working as an engineer or having an engineering degree alone does not qualify. Instead, training by leading consultants and instructors is strongly advised.

Training should be followed by certification compliant to ISO 18436-4 and similar standards. Noria recommends that engineering specifications for new equipment only be written by professionals with Machine Lubricant Analyst (MLA) Level II and III certification credentials. A specification should address many, if not all, of the maintainability features shown in the preceding tables. It must also address hardware and design features that are not permitted. These might include ring oilers, drip oilers, screen filters, snorkel vents, high-watt-density tank heaters, long pump suction lines, etc.

Consider having the specification carefully reviewed by an outside lubrication consultant, especially for the most reliability- critical machines. Remember that the cost of retrofitting needed maintainability hardware will be many times the cost of the same hardware when installed at the factory (as part of the original bill-of-material).

Conversely, buying machines stripped to the bones in an attempt to reduce costs is almost always false economy. The astute reliability professional views new equipment in terms of the cost of ownership, not simply the cost of purchase. Most important is the overall machine reliability, which includes repair costs but also equipment utilization (uptime), maintainability (PMs, inspections, etc.), safety and other factors. All of these should drive the business decision to invest in reliability readiness. Take the next step. Learn how Noria can help transform your lubrication program.