PREVENTIVE AND

PREDICTIVE MAINTENANCE

Presented by-Aishwarya MishraIDD-V10408EN004

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 condition1. Rough condition2. 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 replacement2. Unscheduled stoppages3. Repair cost4. Down time5. Equipment overhauling

Maintenance classification

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. Plan2. Do3. Evaluate4. Refine

4. Start PPM practices immediately if you expect to establish an efficient operating system.

A. Start smallB. Sell expansion upon early successesC. Apply A-B-C analysis to selection of equipment

Effect of PPM1. PPM increases-

1. Maintenance staffing2. Repair parts costs

A. Preventive tends to increase parts costB. Predictive reduces parts cost

3. Volume of work that can be planned and scheduled repetitively4. Work load leveling

5. Equipment reliability and uptime

2. PPM decreases-1. Scrap and reject costs2. Downtime costs3. Cost of lost sales volume4. Total cost of maintenance5. Urgent or emergency interrupts due to breakdowns6. Unnecessary damage to equipment7. High priority, randomly occurring unscheduled work8. Material and spare parts inventories9. Total labor required to maintain the facility

PPM is comprised of

1. Proper organization2. Proper operation of equipment3. The proper lubricants, in the right quantities, in the right location, at the proper time4. Predicting wear and deterioration by regularly checking, measuring and adjusting

A. Regular inspection to identify small repairs before they become major repairsB. Predictive techniques to replace components just before they fail

a. Vibration monitoring and analysisb. Infrared inspectionc. Sound detectiond. Lubrication and oil samplinge. Etc.

5. Replacement of components on a regular basis before they fail6. Correction of potential failures when inspection indicates the need7. Overhauling equipment periodically to upgrade general equipment condition8. Reliability engineering to reduce or eliminate repetitive failures9. Reliability engineering to minimize failures through adjustments to the PPM program

Preventive Maintenance Impact

Predictive Maintenance

Why perform predictive maintenance?1. Monitoring detects degrading conditions2. Most cost failures result from degrading conditions3. Trending degradation permits planning for repair4. Trending degradation permits scheduling repair

What are the concerns of predictive maintenance?1. Doing only predictive maintenance is living close to the edge2. Takes courage to make the initial calls for repairs3. 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 established2. Only with corporate/management support

Typical Predictive Techniques

MonitoringTechniques

Use Problem Detection

Vibration Rotating machinery, e.g., pumps

Misalignment, imbalance,defective bearings, mechanicallooseness

Shock Pulse Rotating machinery Trends of bearing condition

Fluid Analysis Lubrication, cooling Excessive wear of bearingsurfaces fluid contamination

Infrared Thermography Boilers, steam systemcomponents

Leaky steam traps, boilerrefractory cracks, deterioratedinsulation

Signature analysis, time domainand frequency domain

Rectifiers, power supplies,inverters, AC and DC regulators

Degraded solid state circuits andother electrical components

Performance trending Heat exchangers, internalcombustion engines

Loss in efficiency, deterioratingperformance trends

Ultrasonic leak detectors Steam hydraulic and pneumaticsystem piping

Leaking valves, system leaks

Fault gas analysis and insulatingliquid analysis

Circuit breakers, transformers

Overheating, acceleratedDeterioration

Protection relay testing and timetravel analysis

Circuit breakers, transformers andother protective devices

Deteriorating or unsafePerformance

Wear and dimensionalmeasurements

Sliding, rotating and reciprocatingelements

Excessive wear and proximity tominimum acceptable dimensionswhich affect performance

Program (sequence of major steps)

1. Assess the NeedA. Analyze equipment historyB. Review available records

a. Downtimeb. Defectsc. Yield Lossesd. Energy Lossese. Regulatory Finesf. Work Place Accidents

C. Establish definitions, principles and conceptsD. Build a Case

2. Inventory EquipmentA. Establish a plant-wide equipment identification system

3. Appraise Equipment ConditionA. 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?

4. Develop System Details by Individual System/Component5. Organize for a Successful Program

Develop a program plan establishing functions, responsibilities, training and equipment

needs, budgetary requirements, etc.a. Establish total PPM workloadb. Determine necessary PPM staffing

6. Upgrade Equipment to Maintainable Condition, as Defined in the Plan7. 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 system9. Put PPM scheme into operation10. Activate reliability-engineering review

THANK YOU