Predictive Maintenance (PdM) programs provide proven methodologies and use technologies to evaluate the condition of in-service assets by predicting optimal times for corrective equipment maintenance based on a direct relationship between an asset and operating conditions.
PdM provides a high return on investment (ROI) by virtually eliminating catastrophic failure. When you know which equipment needs maintenance and why, PdM replaces unscheduled maintenance stops without shutting down most of the equipment, thus increasing operational uptime. If the equipment shut down is scheduled, PdM offers a quicker turnaround as well as Lockout/Tagout protocols, ensuring that machines are properly shut off and not restarted prior to the completion of service. Other advantages include:
- Extended equipment lifetime
- Lower impact on the environment
- Optimized spare parts handling
An effective PdM program uses non-destructive testing, such as:
Acoustic Emission Analysis
Acoustic analysis is used for the inspection of critical air and gas conveyance components in your facility, making it possible to “hear” rotating machinery noise that are typically drowned out by ambient noise.
- Ultrasonic technology detects distinctive sounds caused by friction and stress waves. Changes in these waves suggest deteriorating conditions earlier than technologies such as vibration or oil analysis. With proper ultrasonic measurement and analysis, it’s possible to differentiate normal wear from abnormal wear, physical damage, imbalance, and lubrication problems. Ultrasonic detectors also catch corona and arcing of power transmission lines in daytime.
- Infrasonic technology measures the intensity of ultra-low frequencies generated by large, wind turbines near populated areas.
Infrared (IR) light and analysis provides the widest, non-invasive range of applications, from high to low-speed equipment and can be effective for spotting both mechanical and electrical failures. Thermography allows you to “see” a thermal 2D or 3D image of potential problems with power transmission lines, electrical panels, substations, rotary equipment, and other mechanical and process related components that lead to catastrophic damage if not replaced early.
Lubricant analysis extends machine and oil life. There are two categories of lubricant analysis, Used Oil Analysis and Wear Particle Analysis:
- Used Oil Analysis determines the condition and quality of the lubricant and its suitability for continued use;
- Wear Particle Analysis determines the mechanical condition of lubricated machine components, allowing you to detect and identify the composition of solid material present and evaluate particle type, size, concentration, distribution, and morphology.
Vibration analysis is most effective on high-speed rotating equipment. Vibration analysis easily diagnoses pending equipment failures as well as lubrication needs. According to ISA Automation Week, 25 years of documented savings show a 20:1 benefit-to-cost ratio for vibration analysis programs.
In conclusion, the advantages of a PdM program are manifold and should be an integral part of any serious maintenance program. The US Department of Energy (DOE) estimates an 8%–12% cost savings over preventive maintenance. In fact, according to the DOE, the following average savings are typical within industrial settings:
- Up to 1000% ROI
- 70%–75% reduction in equipment breakdowns
- 35%–45% reduction in process downtime
- 25%–30% reduction in maintenance costs, including parts and labor
- 20%–25% increase in production