national aeronautics and space administration reliability centered maintenance guide for facilities

618 Pages·2010·9.98 MB·English

NATIONAL AERONAUTICS
AND SPACE ADMINISTRATION
RELIABILITY CENTERED MAINTENANCE
GUIDE FOR
FACILITIES AND COLLATERAL EQUIPMENT
NASA Reliability Centered Maintenance Guide for Facilities and Collateral Equipment
Table of Contents
Chapter 1-Background........................................................................................................1−1
1.1 Introduction.....................................................................................................1−1
1.2 Historical Evolution of RCM...........................................................................1−1
1.3 Purpose of This Guide......................................................................................1−4
1.4 Applicability and Use of This Guide................................................................1−4
Chapter 2Reliability Centered Maintenance (RCM) Approach............................................2−7
2.1 Philosophy.......................................................................................................2−7
2.2 RCM Analysis.................................................................................................2−7
2.3 RCM Principles...............................................................................................2−9
2.4 Failure...........................................................................................................2−11
2.4.1 System and System Boundary...........................................................2−11
2.4.2 Function and Functional Failure........................................................2−13
2.4.3 Failure Modes...................................................................................2−13
2.4.4 Reliability.........................................................................................2−13
2.4.5 Failure Characteristics.......................................................................2−14
2.4.6 Preventing Failure.............................................................................2−16
2.5 Failure Modes and Effects Analysis...............................................................2−17
2.5.1 Criticality and Probability of Occurrence..........................................2−18
2.5.2 Cause of Failure................................................................................2−20
2.6 Reliability Centered Maintenance Goals........................................................2−23
2.7 Program Benefits...........................................................................................2−24
2.7.1 Safety...............................................................................................2−24
2.7.2 Cost..................................................................................................2−24
2.7.3 Reliability.........................................................................................2−24
2.7.4 Scheduling........................................................................................2−24
2.7.5 Efficiency/Productivity.....................................................................2−25
2.8 Impact of RCM on the Facilities Life Cycle...................................................2−25
Chapter 3 RCM Program Components..............................................................................3−27
3.1 Reactive Maintenance....................................................................................327
3.1.1 Reactive Maintenance Criteria..........................................................328
3.2 Preventive Maintenance (PM)........................................................................329
3.2.1 Preventive Maintenance Criteria.......................................................329
3.2.2 Determining PM Task and Monitoring Periodicity............................329
3.3 Predictive Testing & Inspection (PT&I).........................................................331
3.3.1 Data Correlation...............................................................................332
3.4 Proactive Maintenance...................................................................................333
3.4.1 Specifications for New/rebuilt Equipment.........................................334
3.4.2 Precision Rebuild and Installation.....................................................335
3.4.3 Failed-Part Analysis..........................................................................343
3.4.4 Root-Cause Failure Analysis (RCFA)...............................................343
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3.4.5 Reliability Engineering.....................................................................344
3.4.6 Reliability Calculations.....................................................................344
3.4.7 Rebuild Certification/Verification.....................................................348
3.4.8 Age Exploration................................................................................348
3.4.9 Recurrence Control...........................................................................349
3.4.10 Facilities Condition Assessment........................................................354
Chapter 4 Predictive Testing & Inspection (PT&I) Technologies......................................457
4.1 Introduction...................................................................................................457
4.1.1 Alerts and Alarms.............................................................................457
4.2 Vibration Monitoring & Analysis...................................................................459
4.2.1 Applications and Techniques............................................................459
4.2.2 Limitations.......................................................................................462
4.2.3 Logistics...........................................................................................462
4.3 Thermography...............................................................................................463
4.3.1 Applications......................................................................................463
4.3.2 Limitations.......................................................................................464
4.3.3 Logistics...........................................................................................464
4.4 Passive (Airborne) Ultrasonics.......................................................................465
4.4.1 Applications and Procedures.............................................................465
4.4.2 Limitations.......................................................................................468
4.4.3 Logistics...........................................................................................468
4.5 Lubricant and Wear Particle Analysis............................................................469
4.5.1 Purpose.............................................................................................469
4.5.2 Standard Analytical Tests.................................................................470
4.5.3 Special Tests.....................................................................................472
4.5.4 Application.......................................................................................473
4.5.5 Sampling..........................................................................................477
4.6 Electrical Condition Monitoring.....................................................................477
4.6.1 Techniques........................................................................................477
4.6.2 Additional Techniques and Troubleshooting.....................................484
4.6.3 Applications......................................................................................486
4.6.4 Logistics............................................................................................4-87
4.7 Non-Destructive Testing................................................................................488
4.7.1 Techniques........................................................................................489
4.7.2 Location & Intervals.........................................................................493
4.7.3 Applications......................................................................................497
4.7.4 Limitations.......................................................................................497
4.8 Photography....................................................................................................4-99
Chapter 5RCM Requirements During Facilities Acquisition.............................................5101
5.1 Planning.......................................................................................................5101
5.2 Design.........................................................................................................5101
5.2.1 Maintainability and Ease of Monitoring..........................................5101
5.2.2 Technology Review........................................................................5102
5.3 Construction................................................................................................5103
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5.4 Maintenance and Operations (M&O)...........................................................5104
Chapter 6RCM Considerations During Facilities Operation..............................................6105
6.1 RCM Program Data.....................................................................................6105
6.2 Maintenance Feedback.................................................................................6105
6.3 Maintenance and Operations (M&O) Considerations...................................6106
Chapter 7RCM Contract Clauses.......................................................................................7111
7.1 General Contract Clauses.............................................................................7112
7.1.1 Measurements and Measurement Data............................................7112
7.1.2 Bearing Information........................................................................7112
7.1.3 Gearbox Information.......................................................................7112
7.1.4 Pumps.............................................................................................7113
7.1.5 Centrifugal Compressors.................................................................7113
7.1.6 Fans................................................................................................7113
7.1.7 Vibration Monitoring......................................................................7114
7.1.8 Vibration Monitoring Locations......................................................7122
7.1.9 Lubricant and Wear Particle Analysis.............................................7124
7.1.10 Thermography................................................................................7129
7.1.11 Airborne Ultrasonics.......................................................................7130
7.1.12 Pulse Echo Ultrasonics....................................................................7131
7.1.13 Motor Circuit Analysis (Complex Phase Impedance)......................7131
7.1.14 Motor Current Spectrum Analysis...................................................7131
7.1.15 Insulation Resistance......................................................................7131
7.1.16 Surge Testing..................................................................................7131
7.1.17 Start-Up Tests.................................................................................7132
7.1.18 Maintainability and Ease of Monitoring..........................................7132
7.1.19 Leveling of Equipment Upon Installation........................................7132
7.2 Architectural/Engineering (A&E) Contracts.................................................7132
7.3 Construction Contracts.................................................................................7133
7.4 Equipment Procurement Contracts...............................................................7134
7.5 Maintenance and Operations (M&O) Contracts...........................................7135
Chapter 8PT&I Criteria....................................................................................................8137
8.1 Baselines.....................................................................................................8137
8.2 Criteria by PT&I Technology.......................................................................8137
8.2.1 Vibration Monitoring......................................................................8137
8.2.2 Lubricant and Wear Particle Analysis.............................................8139
8.2.3 Thermography................................................................................8140
8.2.4 Airborne Ultrasonics.......................................................................8141
8.2.5 Motor Circuit Analysis....................................................................8142
8.2.6 Motor Current Spectrum Analysis (MCSA)....................................8145
8.2.7 Insulation Resistance......................................................................8145
8.2.8 Surge Testing..................................................................................8146
8.2.9 Start-Up Tests.................................................................................8147
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Chapter 9Checklists for RCM Quality Assurance..............................................................9149
9.1 Planning.......................................................................................................9149
9.2 Design.........................................................................................................9150
9.3 Construction................................................................................................9151
9.4 Equipment Procurement...............................................................................9151
9.5 Maintenance and Operations........................................................................9152
Chapter 10Management Indicators..................................................................................10153
10.1 General......................................................................................................10153
10.2 Purpose of Metrics.....................................................................................10153
10.2.1 Metrics Ownership.........................................................................10154
10.2.2 Definition of Metrics.......................................................................10-154
10.3 SampleMetrics..........................................................................................10155
10.4 Trending Indicators....................................................................................10156
10.5 Recommended Agencywide Facilities Metrics...........................................10157
10.6 Metric Selection.........................................................................................10158
10.7 Benchmark Selection .................................................................................10-158
10.8 Utilization of Metrics..................................................................................10-158
10.9 Examples of Benchmarks............................................................................10-159
10.10 Planning & Scheduling Metrics...................................................................10-163
10.11 RCM Metrics..............................................................................................10-164
Appendix AGlossary........................................................................................................A167
AppendixBAbbreviations/Acronyms...............................................................................B175
AppendixCBibliography.................................................................................................C179
AppendixDSources of PT&I Equipment, Services, and Training....................................D185
AppendixEVibration Criteria..........................................................................................E191
Appendix FPT&I Technologies Correlation Relationships...............................................F231
Appendix G—Alignment Standard....................................................................................G243
Appendix H—Balance Standard........................................................................................H257
Appendix I—AC Motor Repair and Reconditioning.............................................................I267
Appendix J—Maintenance Procedures.................................................................................J275
Appendix K—SPECSINTACT Clauses with RCM Applications.......................................K323
List of Tables
2-1. Criticality/Severity Categories...................................................................2-18
2-2. Probability of Occurrence Categories........................................................2-20
2-3. Chilled Water System Analysis.................................................................2-21
2-4. Electric Motor Component Analysis..........................................................2-22
2-5. Cause of Motor Bearing Failure................................................................2-23
2-6. RCM Facility Life-Cycle Implications......................................................2-26
3–1. Maintenance Priority Levels......................................................................3-27
3–2. Reactive Maintenance Priorities................................................................3-28
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NASA Reliability Centered Maintenance Guide for Facilities and Collateral Equipment
3–3. Balance Quality Grades for Various Groups of Representative Rigid
Rotors (ISO 1940/1-1986).........................................................................3-37
3–4. Recommended Coupled Alignment Tolerances (General Motors, 1993)....3-40
3–5. Alignment Related Tolerances (General Motors, 1993).............................3-40
3–6. Limitations on Rolling Bearing Misalignment (Harris,1984).....................3-41
3–7. Equipment Condition Classification Based on PT&I Data.........................3-55
4–1. Estimated Steam Loss...............................................................................4-67
4–2. Recommended Maximum Inspection Intervals (API 570).........................4-94
6–1. Maintenance Training.............................................................................6-108
7–1. Motor Balance Specifications..................................................................7-118
7–2. Motor Vibration Criteria.........................................................................7-118
7–3. Pump Vibration Limits............................................................................7-119
7–4. Belt-Driven Fan Vibration Limits............................................................7-120
7–5. ISO 3945 Vibration Severity Table.........................................................7-121
7–6. Vibration Acceptance Classes.................................................................7-121
7–7. Machine Classifications..........................................................................7-122
7–8. Lubricant Tests.......................................................................................7-126
7–9. Sperry Vickers Table of Suggested Acceptable Contamination Levels
for Various Hydraulic Systems................................................................7-127
7–10. Typical Properties of Transformer Oils...................................................7-128
7–11. RCM Clauses for A&E Contracts............................................................7-132
7–12. RCM Clauses for Construction Contracts................................................7-134
7–13. RCM Clauses for Equipment Procurement Contracts..............................7-135
7–14. RCM Clauses for M&O Contracts...........................................................7-136
8–1. Actions Required Based on Temperature Rise Under Load.....................8-141
8–2. Temperature Limits for Selected Components.........................................8-142
9–1. RCM Quality Assurance Planning Considerations...................................9-149
9–2. RCM Quality Assurance Design Considerations......................................9-150
9–3. RCM Quality Assurance Construction Considerations.............................9-151
9–4. RCM Quality Assurance Equipment Procurement Considerations...........9-151
9–5. RCM Quality Assurance Maintenance and Operations Considerations....9-152
10–1. Financial Benchmarks...........................................................................10-160
10–2. Organizational Benchmarks..................................................................10-161
10–3. Work Practices Benchmarks..................................................................10-161
10–3. Work Practices Data (Cont.)..................................................................10-162
List of Figures
1-1. Components of an RCM Program................................................................1-1
1-2. Bearing Life Scatter....................................................................................1-3
1-3. RCM Strategy and Process..........................................................................1-5
2-1. RCM Analysis Considerations....................................................................2-8
2-2. Maintenance Analysis Process .................................................................2-10
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NASA Reliability Centered Maintenance Guide for Facilities and Collateral Equipment
2-3. Reliability Centered Maintenance (RCM) Decision Logic Tree.................2-12
2-4. Conditional Probability of Failure Curves.................................................2-15
2-5. Preventing Failure.....................................................................................2-17
2-6. FMEA Worksheet.....................................................................................2-19
2-7. Stages of Life-Cycle Cost Commitment....................................................2-26
3-1. Sample System..........................................................................................3-33
3-2. Effects of Misalignment on Roller Bearings..............................................3-42
3-3. Determining Network Reliability..............................................................3-47
3-4. Failure Analysis Form...............................................................................3-53
3-5. Mean and Standard Deviation...................................................................3-54
3-6. Office Assessment Form...........................................................................3-56
4-1. PT&I Applications....................................................................................4-58
4-2. Sound Disc Diagram.................................................................................4-61
4-3. Lubrication Analysis Chart.......................................................................4-76
4-4. Power Factor Current/Voltage Relationship..............................................4-79
4-5. NDT Technique Selection Process............................................................4-88
4-6. Shielded Radiography Enclosure...............................................................4-90
4-7. Magnetic Particle Testing..........................................................................4-92
4-8. Inspection Program Development.............................................................4-96
6-1. Design Improvements through Maintenance Feedback............................6-107
7-1. Transducer Response..............................................................................7-115
8-1. Wear Particle Size and Equipment Condition..........................................8-140
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NASA Reliability Centered Maintenance Guide for Facilities and Collateral Equipment
Chapter 1 - Background
1.1 Introduction
Reliability Centered Maintenance (RCM) is the process that is used to determine the most
effective approach to maintenance. It involves identifying actions that, when taken, will reduce
the probability of failure and which are the most cost effective. It seeks the optimal mix of
Condition-Based Actions, other Time- or Cycle-Based actions, or a Run-to-Failure approach, as
shown in Figure 1-1. The principal features of each strategy are shown below their block in
Figure 1-1. RCM is an ongoing process that gathers data from operating systems performance
and uses this data to improve design and future maintenance. These maintenance strategies,
rather than being applied independently, are integrated to take advantage of their respective
strengths in order to optimize facility and equipment operability and efficiency while minimizing
life-cycle costs. The elements of RCM are developed in Chapter 2 and the maintenance
strategies are defined and discussed in Chapter 3.
Reliability
CenMtaeirnetdenance
Reactive Preventive Predictive Proactive
• Small items • Subject to wear- • Random failure • RCFA
• Non-critical out patterns • Age
• Inconsequential • Consumable • Not subject to Exploration
• Unlikely to fail replacement wear • FMEA
• Redundant • Failure pattern • PM induced
known failures
Figure 1–1. Components of an RCM Program
1.2 Historical Evolution of RCM
Analysis of maintenance policy in the airline industry in the late 1960's and early 1970's led to
the development of Reliability Centered Maintenance (RCM) concepts. The principles and
applications of RCM were documented in Nowlan and Heap's publication, Reliability-Centered
Maintenance.1 The work demonstrated that a strong correlation between age and failure rate did
not exist and the basic premise of time based maintenance was false for the majority of
equipment. Additional studies performed by the Department of Defense (DOD) and several
nuclear utilities confirmed Nowlan and Heap's work.
1F. Stanley Nowlan and Howard F. Heap. Reliability-Centered Maintenance. United Airlines and Dolby Press,
sponsored and published by the Office of Assistant Secretary of Defense, 1978.
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NASA Reliability Centered Maintenance Guide for Facilities and Collateral Equipment
From approximately 1960 until the late 1980s, Preventive Maintenance (PM) was the most
advanced technique used by progressive facilities maintenance organizations. PM is based on
two principles - 1) a strong correlation exists between equipment age and failure rate, and 2)
individual component and equipment probability of failure can be determined statistically, and
therefore, parts can be replaced or rebuilt prior to failure.
PM assumes that failure probabilities can be determined statistically for individual machines and
components and parts or adjustments can be replaced or performed in time to preclude failure.
For example, a common practice in the past was to replace or renew bearings after some number
of operating hours based on the assumption that bearing failure rate increases with time in
service. This has proven to be ineffective.
Figure 1–2 shows the failure distribution of a group of thirty identical 6309 deep groove ball
bearings installed on bearing life test machines and run to failure. The wide variation in bearing
life is obvious and precludes the use of any effective time-based maintenance strategy2. The X-
axis is the individual bearing being tested while the Y-axis is the number of revolutions achieved
prior to fatigue failure of the individual bearing. It should be noted that the bearings are tested at
above-design loads to accelerate the failure rate. This is the standard procedure used to test
bearings in order to determine the expected life of a bearing.
In all the studies, it was noted that a difference existed between the perceived and the intrinsic
design life for the majority of equipment and components. In fact, it was discovered that in
many cases equipment bearing life greatly exceeded the perceived or stated design life. For
example, SKF Industries proposed changes in the method for evaluating bearing life - from the
original method (empirical) proposed by Lundberg and Palmgren3to one where "bearings exhibit
a minimum fatigue life; that is, 'crib deaths' due to rolling contact fatigue are non-existent when
the aforementioned operating conditions (properly lubricated, mounted, operated and protected
from dirt and moisture) are achieved."4 This lack of a predefined fatigue life for bearings greatly
impacts the concept of a predetermined design life for rotating equipment where rolling element
bearings are used and provides the basis for extending the time between overhauls and
equipment replacement.
This process, known as Age Exploration (AE), was used by the U.S. Submarine Force in the
early 1970's to extend the time between periodic overhauls and to replace time based tasks with
condition based tasks. While the initial program was limited to Fleet Ballistic Missile (FBM)
submarines, it was continuously expanded until it included all submarines, aircraft carriers, other
major combatants, and ships of the Military Sealift Command (MSC). Furthermore, the Navy
has invoked the requirements of RCM and condition monitoring as part of new ship design
specifications.
It should not be inferred from the above that all interval based maintenance should be replaced
by condition based maintenance. In fact, interval based maintenance is often appropriate for
2Eschmann, et al, Ball and Roller Bearings: Theory, Design, & Application, John Wiley & Sons, 1985
3G.Lundberg and A. Palmgren,Dynamic Capacity of Roller Bearings,AcraPolytech, Mechanical Engineering
Series 1, R.S.A.E.E., No. 3, 7, 1947.
4Tedric A. Harris, Roller Bearing Analysis, Second Edition, John Wiley and Sons, New York, 1984
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NASA Reliability Centered Maintenance Guide for Facilities and Collateral Equipment
those instances where an abrasive, erosive, or corrosive wear takes place, material properties
change due to fatigue, embrittlement, etc. and/or a clear correlation between age and functional
reliability exists.
Development of new technologies during the 1990's, including affordable microprocessors and
increased computer literacy in the work force, has made it possible to determine the actual
condition of equipment and not have to rely upon estimates of when the equipment might fail
based on age. These new cost effective technologies and the lack of correlation between age and
failure in many equipment items have increased the emphasis on condition monitoring.
Condition monitoring, commonly called Predictive Testing and Inspection (PT&I) within the
NASA facilities maintenance environment, has resulted in a need to review existing Preventive
(PM) and Programmed (PGM) Maintenance efforts and ensure that the most effective approach
is being used. RCM provides the structure for developing that approach.
Closely aligned with determining what maintenance approach to use are the subjects of who
should do the work and what parts and material will be needed to ensure that the work is done in
the most cost efficient manner.
Most recently, RCM has taken on a prominent role in NASA's facility and equipment
maintenance and operations program. RCM principles have been integrated into the
SPECSINTACT (See Appendix K, Clauses with RCM Applications) wherein designs now have
requirements for designing to maintainability. PT&I is used within the construction contractor's
quality control program before and during commissioning to ensure that there are no latent
manufacturing and installation defects at the time of equipment acceptance. PT&I and proactive
Thirty Identical 6309 Deep Groove
Ball Bearings Run to Fatigue Failure
Under Test Load Conditions
1 5 10 15 20 25 30
Bearing Number From: Ball and Roller Theory,
Design, & Application.
Eschmann, et al
John Wiley & Sons, 1985
Figure 1-2:Bearing Life Scatter
analyses are used as tools by NASA Quality Assurance Evaluators (QAEs) to monitor the
contractor's compliance with the specific requirements of performance based contracts. RCM is
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