Preventive and predictive maintainence
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This document discusses preventive and predictive maintenance. It defines maintenance as upkeeping equipment to preserve reliability. There are two types of maintenance: preventive, which involves regularly scheduled inspections and services to avoid breakdowns, and predictive, which uses monitoring techniques like vibration analysis to detect deterioration and schedule repairs before failures occur. The benefits of preventive and predictive maintenance programs include increased equipment uptime and reliability while decreasing costs from unexpected breakdowns. The document outlines steps to develop an effective maintenance program, including assessing equipment needs, developing maintenance plans, and continuously improving based on equipment history data.
Preventive and predictive maintainence
- 2. What is MAINTENANCE • Up keeping of a property or an equipment. • Process of preserving reliability and not achieving it. • Parameters to be taken in account are- 1. Equipment working condition 1. Rough condition 2. Smooth condition 2. Condition of its parts like belts, gaskets, filters etc. 3. Equipment history. 1. Most imp. Factor. 2. Prominent indicators are- 1. Parts replacement 2. Unscheduled stoppages 3. Repair cost 4. Down time 5. Equipment overhauling
- 4. Effective PPM requirements 1. Understanding of the true cost of poor maintenance. 2. Knowledge of equipment/process conditions required to yield quality, output, safety, and compliance standards. 3. PPM must be conducted as a Controlled Experiment 1. Plan 2. Do 3. Evaluate 4. Refine 4. Start PPM practices immediately if you expect to establish an efficient operating system. A. Start small B. Sell expansion upon early successes C. Apply A-B-C analysis to selection of equipment
- 6. Effect of PPM 1. PPM increases- 1. Maintenance staffing 2. Repair parts costs A. Preventive tends to increase parts cost B. Predictive reduces parts cost 3. Volume of work that can be planned and scheduled repetitively 4. Work load leveling 5. Equipment reliability and uptime 2. PPM decreases- 1. Scrap and reject costs 2. Downtime costs 3. Cost of lost sales volume 4. Total cost of maintenance 5. Urgent or emergency interrupts due to breakdowns 6. Unnecessary damage to equipment 7. High priority, randomly occurring unscheduled work 8. Material and spare parts inventories 9. Total labor required to maintain the facility
- 7. PPM is comprised of 1. Proper organization 2. Proper operation of equipment 3. The proper lubricants, in the right quantities, in the right location, at the proper time 4. Predicting wear and deterioration by regularly checking, measuring and adjusting A. Regular inspection to identify small repairs before they become major repairs B. Predictive techniques to replace components just before they fail a. Vibration monitoring and analysis b. Infrared inspection c. Sound detection d. Lubrication and oil sampling e. Etc. 5. Replacement of components on a regular basis before they fail 6. Correction of potential failures when inspection indicates the need 7. Overhauling equipment periodically to upgrade general equipment condition 8. Reliability engineering to reduce or eliminate repetitive failures 9. Reliability engineering to minimize failures through adjustments to the PPM program
- 9. Predictive Maintenance Why perform predictive maintenance? 1. Monitoring detects degrading conditions 2. Most cost failures result from degrading conditions 3. Trending degradation permits planning for repair 4. Trending degradation permits scheduling repair What are the concerns of predictive maintenance? 1. Doing only predictive maintenance is living close to the edge 2. Takes courage to make the initial calls for repairs 3. Must be an adjunct to a sound preventive maintenance program When should you consider a predictive maintenance program? 1. After the preventive maintenance program is established 2. Only with corporate/management support
- 10. Typical Predictive Techniques Monitoring Techniques Use Problem Detection Vibration Rotating machinery, e.g., pumps Misalignment, imbalance, defective bearings, mechanical looseness Shock Pulse Rotating machinery Trends of bearing condition Fluid Analysis Lubrication, cooling Excessive wear of bearing surfaces fluid contamination Infrared Thermography Boilers, steam system components Leaky steam traps, boiler refractory cracks, deteriorated insulation Signature analysis, time domain and frequency domain Rectifiers, power supplies, inverters, AC and DC regulators Degraded solid state circuits and other electrical components
- 11. Performance trending Heat exchangers, internal combustion engines Loss in efficiency, deteriorating performance trends Ultrasonic leak detectors Steam hydraulic and pneumatic system piping Leaking valves, system leaks Fault gas analysis and insulating liquid analysis Circuit breakers, transformers Overheating, accelerated Deterioration Protection relay testing and time travel analysis Circuit breakers, transformers and other protective devices Deteriorating or unsafe Performance Wear and dimensional measurements Sliding, rotating and reciprocating elements Excessive wear and proximity to minimum acceptable dimensions which affect performance
- 12. Program (sequence of major steps) 1. Assess the Need A. Analyze equipment history B. Review available records a. Downtime b. Defects c. Yield Losses d. Energy Losses e. Regulatory Fines f. Work Place Accidents C. Establish definitions, principles and concepts D. Build a Case 2. Inventory Equipment A. Establish a plant-wide equipment identification system 3. Appraise Equipment Condition A. Can it be easily maintained in its present condition? If not; B. Can it be upgraded to maintainable condition? If not; C. How can it be taken out of service and how much will it cost?
- 13. 4. Develop System Details by Individual System/Component 5. Organize for a Successful Program Develop a program plan establishing functions, responsibilities, training and equipment needs, budgetary requirements, etc. a. Establish total PPM workload b. Determine necessary PPM staffing 6. Upgrade Equipment to Maintainable Condition, as Defined in the Plan 7. Set up equipment history A. Create permanent files and records on PPM work performed (including costs) B. Develop files of completed PPM work orders and resultant corrective work orders 8. Create computerized program to fit needs of the PPM system 9. Put PPM scheme into operation 10. Activate reliability-engineering review