The process of proper lubrication

The right work procedures drive consistency and ensure success

06/19/2013


Figure 1: Proper lubrication is an important factor in the manufacturing of plastic injection moulding for Blu-Ray DVD cases. Courtesy: Shell/AGI Freden S.A.Work procedures are a cornerstone of proper work execution and the reliability process, ensuring that equipment availability requirements are met to deliver business results. When effectively written, these procedures reduce human performance variability, thus maximizing both mean time between failures (MTBF) and the mean time to repair/replace (MTTR).

All work should have a procedure. Well-written, updated, and frequently utilized work procedures demonstrate a deep understanding of reliability within an organization. When effective work procedures are used across a facility, the work environment will stabilize and the culture will change to one that is more reliable. This includes a facility’s lubrication program. When properly developed and utilized, effective work procedures are completely accurate and drive standard, reliable results, along with improved schedule compliance, which helps develop trust and partnership between departments.

Further, repeatable and effective written procedures remove concern about how to train new employees as the procedure becomes the training document and eases the growing concern about the increasing number of plant personnel retiring since their specialized knowledge is contained within a procedure. 

Work procedure basics

As previously stated, work procedures drive consistency of execution, especially among people of different skill levels. However, this can only happen if the procedures are repeatable, clear and concise, and measurable; have standards and specifications defined; and are followed in a disciplined manner. To ensure that these principles are adhered to, all work procedures should go through a management-level quality assurance/quality control process.

Many times, there is an assumption that everyone should know how to perform a task. However, that is not often the case, especially when talking about utilizing a best practice. As an example, review some of the procedures that are used at your site. How clear, vague, precise, or understandable are they?

While the list below is by no means a complete list of what can and should be required in a work procedure, the following elements are a good starting point for ensuring that your procedures are effective:

  1. Coordination requirements
  2. Special permits
  3. Craft skills requirements and number of each craft
  4. Equipment condition necessary for work to occur
  5. Required parts/potential parts, consumables, and special tools and/or equipment
  6. Estimated time required
  7. Approvals necessary prior to beginning work
  8. Step-by-step procedures
  9. Lockout/tagout information
  10. Specifications/standards
  11. Explicit warnings and cautions
  12. Notes for clarification
  13. Quantitative measurement points, inspection criteria
  14. Reference information (drawings, sketches, photographs, OEM manuals, standards, specifications) 

Work procedures in lubrication

Now, look specifically at a re-grease procedure. What should a re-grease procedure look like?

Each of the following procedures was condensed from the original, so focus on the level of detail and select the procedure that is comparable to your site’s procedure.

  • Re-grease bearing using the appropriate amount of the manufacturer-recommended grease at the appropriate interval.
  • Re-grease bearing using approximately 12 shots of food-grade grease as needed.
  • Re-grease electric motor bearing using approximately 12 shots of food-grade grease every 30 days.
  • Re-grease electric motor bearing using approximately 0.55 ounces of Mobil Polyrex EM grease every 90 days.

Remember, work procedures provide a set of guidelines and/or process for completing a task. This set of guidelines and processes should limit the amount of extrapolation that must occur to complete the task. By “extrapolate,” I am referring to the amount of variables that must be filled in, such as how much grease, what type of grease, and when the re-greasing should occur. Without going into a complete explanation of each answer, I do want to make a point about extrapolation through the following example.

Four maintenance technicians were presented with the task to re-grease a set of bearings for a conveyor asset. They were given Procedure A, “Re-grease bearing using the appropriate amount of the manufacturer-recommended grease at the appropriate interval.” Table 1 outlines what each technician concluded the meaning of the procedure to be.

Table 1: Technicians' understanding of a work procedure

Table 1: Technicians' understanding of a work procedure. Courtesy: Shell/AGI Freden S.A.

As you can see, there were some discrepancies between each technician’s idea of what were an appropriate interval, amount, and type of grease. These discrepancies can lead to component failure. 

Re-grease procedure best practices

While it is generally accepted that grease should be applied in small amounts more often, it is important to ensure that an amount is specified that relates to the bearing size and that amount should also be correlated to a set interval. The goal is to not over grease the bearing, but to maintain approximately a 30% to 40% fill based on internal open volume.

Grease mixing is another concern since not all greases are compatible. Issues with softening or hardening due to grease thickener incompatibility may be experienced, or with a viscosity that is too thick or thin. This mixing of greases can lead to an inability to provide a proper lubricant film to separate the moving surfaces, thus leading to friction, which generates heat and causes wear.

Procedure D includes some very specific elements for completing the task. These elements minimize the amount of extrapolation that must occur and lay out a very specific course of action. The specific steps provide benefits to the maintenance and production teams as a whole:

  • Eases the burden of training new lubrication personnel
  • Minimizes inconsistencies with work performed by a backup technician
  • Allows for a broader group of people to perform basic tasks
  • Minimizes the possibility of cross-contamination of lubricants
  • Minimizes the risk of over application of lubricant due to interval or volume applied. 

At a minimum, the elements that should be included in a lubrication procedure (in addition to those elements already identified for any effective procedure) include:

  • The specific component, especially for complex equipment with different sized components and operating speeds
  • The required lubricant (proper product name)
  • The required amount of lubricant (ounces, grams, liters, quarts, gallons)
  •  NOTE: For greases, try to eliminate the use of “shots” as different grease guns are calibrated differently and dispense a different amount of grease per shot.
  • The interval (days, months, hours). 

Keep in mind that a complete procedure will have more information that would include the steps specific to completing the task, such as safety requirements, lubricant application methods (manual, ultrasound, offline, etc.), steps specific to best practice, steps specific for access to component, etc. The more detailed and user friendly a procedure, the more consistently the task will be completed. Consistency will increase the life and reliability of any component. 

Next steps

Having reviewed the elements that should be included in lubrication-related work procedures, now would be a good time to take a close look at your facility’s procedures to ensure that you have effective procedures, and that they are being used. If needed, write, rewrite, or modify your procedures so that they meet the standards included here. Then, measure the performance of these procedures. That is the only way to ensure they are driving the consistency they should be and that your facility is successfully executing work.

Stacy Heston, CLS, PMP, CMRP, OMA, is a lubrication subject matter Expert for Allied Reliability, Inc

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