A Proactive Lifestyle for Your Machines – Focus on FLAB
By Drew D. Troyer
Precision equipment care proactively targets the root causes of machine failure with the specific intent to increase equipment reliability. Proactively managing the mechanical and electrical aspects of fasteners, lubrication, alignment, and balance (FLAB) can increase equipment life, drive equipment reliability, reduce maintenance costs, and support an organization’s environmental sustainability objectives through improved energy efficiency.
August 3, 2020
By Drew D. Troyer
The following introduces the fundamentals of proactive and precision equipment care with a focus on FLAB, illustrates its economic potential, and lays out an implementation plan that will help from the drawing board to execution.
A blood cell-sized film separates reliability and failure in mechanical systems.
Machines, when operating under normal loads, can last a long time, and provide reliable service if the critical clearances between rolling elements and raceways, gear teeth, rings and liners remain effectively separated under dynamic load conditions. Assuring this occurs is the lubricant’s job. The lubricant is a viscous fluid that physically separates surfaces in relative motion. For sliding contacts, separation is referred to as hydrodynamic lubrication. For rolling contacts, separation is referred to as elastohydrodynamic lubrication, as creation of a hydrodynamic lubricant film is dependent upon the temporary elastic deformation of the contacting surfaces.
This lubricant film is very small, under five microns in thickness in rolling contacts and under 10 microns in sliding contacts. To put that in perspective, five microns is approximately the diameter of a red blood cell. Unfortunately, if machines are shaking, noisy, hot, and dirty, that’s an indication that the film has been compromised, which leads to surface-to-surface contact, wear, reduced component and machine life, production losses, and wasted energy.
For mechanical systems, this film is compromised by:
• Looseness, unbalance, misalignment, and resonance increase the load on the critical clearance, which overloads the film.
• Water contamination in the lubricant compromises the oil’s pressure-viscosity relationship. When oil is dry, the viscosity increases as pressure increases. Water compromises that property and the film strength.
• A clearance-sized particle bridges the critical clearance, which localizes the load and causes fatigue in rolling contacts and abrasion in sliding contacts (see Figure 1).
• Degradation or mixing.
In electrical systems, improper wire size, degraded wire, poor connections, and the breakdown of electrical insulation create heat, and stress the electrical systems. Also, voltage, current, inductive and/or resistive unbalance, harmonic distortion, and stray current stress electrical systems.
Focus on FLAB for precision equipment care
Focusing on the four foundational elements (in FLAB) enables you to control the most important root causes of mechanical and electrical wear and tear that compromises reliability of equipment.
Fastener best practices
• Threaded fasteners are properly specified, installed, ten-sioned, inspected, and maintained to ensure a solid connection between parts, machines, and equipment bases.
• Weld inspections assure quality of welded connections.
• Leaks in pipes and hoses are routinely monitored and addressed to reduce liquid, vapour, and gas leaks.
• Electrical fasteners are routinely maintained to assure proper current flow.
Lubrication best practices
• Lubricants are selected to match performance properties with the machine’s performance requirements.
• Lubricants are stored to avoid cross-mixing, accumulation of contamination, and shelf degradation.
• Lubricants are corrected to machines, ensuring that the right lubricant is applied to the right machine using the right method and is delivered in the right condition.
• Contaminants, such as abrasive particles, water, fuel, and anti-freeze, are controlled to extend machine and lubricant life.
• Transformer oils are properly maintained to ensure insulation effectiveness.
Alignment best practices
• Shafts, pulleys, sheaves, and sprockets are precision aligned to minimize angularity and offset, and to prevent vibration, and wear and tear.
• Conveyor belts and other equipment are aligned as required to minimize wear and tear, and to assure reliable operation.
• Electrical alignment minimizes stray current and harmonic distortion.
Balance best practices
• Pump impellers, electric motor rotors, fans, turbomachinery, and other rotating equipment is dynamically balanced to the appropriate ISO 1940 (or API) specification to minimize vibration and wear.
• Electrical voltage, current, resistive and inductive balance are routinely monitored in electric motors and corrected as required.
Best practices for all FLAB elements
• Fit, tolerance, quantity, and quality details are included in all preventive and corrective work plans that require managed fastened connections.
• Connections are routinely monitored with vibration analysis (and lubrication analysis for lubrication), ultrasonic analysis, thermographic/thermometric, non-destructive testing, and visual/sensory inspections as required to identify proactive opportunities that improve reliability.
• Operators and tradespersons write timely, clear, and accurate proactive work requests to address fastener-related proactive opportunities before damage to the machine can occur.
These elements are non-negotiable if you wish to achieve proactive control over machine reliability with precision equipment care.
Putting precision equipment care on the plant floor
To claim the benefits offered by precision equipment care focused on the proactive management of the root causes of failure, you’ll need to answer yes to the following organizational preconditions.
• Business case and strategy – A business case for precision and proactive care of the equipment is developed and includes equipment life extension opportunities, and reduced energy consumption opportunities. A strategy for deploying precision and proactive care is developed and aligns to the organization’s reliability, maintenance, and operational strategies.
• Benchmark / deep dive – A baseline of the current state of the plant with regard to FLAB, relative to predefined optimum reference states, is established. Good practices are identified, and deficits with regard to proactive and precision equipment asset care are highlighted and targeted for improvement and mitigation.
• Proactive and precision talent management – Tradespersons, operators, supervisors, engineers, and managers are appropriately trained and qualified on proactive and precision asset care theory and practice. Formal training is supplemented by active, in-the-field coaching and mentoring to produce a sustainable behavioural change.
• Proactive KPIs and rewards – Metrics are essential for tracking performance and for driving desired behaviours. The majority of asset management metrics are lagging indicators. Proactive and precision equipment asset care demands leading indicators that are focused on the root causes of failure; extrinsic and intrinsic rewards must align to proactive metrics.
• Proactive condition monitoring – Machine condition monitoring activities are focused on controlling the sources of vibration, noise, heat, wear, and failure, with a particular focus on the FLAB optimum reference states. Condition monitoring activities include online, instrument assisted, off-site (laboratory), and sensory/simple devices-assisted inspections.
• Proactive and precision operator asset care – Operators are the first line of defence in the proactive and precision care of equipment assets. Equipment is operated within a sustainable load range. Operators faithfully execute routine inspections and write effective proactive notifications. Operators own and drive asset reliability.
Precision equipment care targets the root causes of machine wear and tear, and failure that compromise the organization’s productivity, cost management, safety, and environmental goals. We want to replace shaky, noisy, hot, and dirty operating conditions with smooth, quiet, cool, and clean conditions. Fortunately, these root causes are very controllable, if we focus on the FLAB.
Drew D. Troyer, CRE, is Principle at T.A. Cook Consultants in The Woodlands, Texas.