Machinery Oil Analysis - Methods, Automation & Benefits 3rd Edition

Excerpt 1

Most industrial machines utilize filtration or are periodically serviced with filter carts. Changing internal filters almost always causes a significant loss of oil that must be made up. Dilution by new oil artificially lowers test results. This effect is proportional to the amount of oil added in relation to the capacity of the system. Small machines tend to lose a higher proportion of total volume during filter changes than large machines.

In some cases, a developing problem such as abnormal wear can be completely masked by a filter change and top-up. In addition, the new filter may exhibit different characteristics, skewing test results even further. When sampling, top-up and/or filter change occurs at the same point in the maintenance schedule, take the sample first.

Excerpt 2

Two of the most critical maintenance activities that impact oil data are oil makeup and change-out. All fluid and machine failure indicators are "concentration measurements". This means the "value" of parameter reported is a function of the volume in the reservoir at the time the sample is taken. Allow the volume to "fluctuate" by infrequent large makeup additions and the test data fluctuate inversely causing interpretation difficulties. Always maintain the reservoirs of operating machinery at the OEM recommended level. If the machine is a heavy oil consumer, add small volumes of makeup oil on a frequent basis. Never wait until the reservoir or sump falls to less than 90% full.

1 Introduction to Oil Analysis
1.1 General Overview
1.2 Oil Analysis Strategies
1.2.1 Analysis of New-Oils
1.2.2 Analysis of Used-Oils
1.2.3 Summary of Oil Analysis Strategies
1.3 Oil Analysis Mission (Benefits)
1.3.1 Benefits Examples
1.4 Historical Perspective
1.4.1 Oil Analysis Technology Milestones

2 Equipment Failure and Maintenance
2.1 Machinery Failures
2.1.1 Early Failures
2.1.2 Random Failures
2.1.3 Time Dependent Failures
2.1.4 Condition Dependent Failures
2.1.5 Maximizing Usable Life
2.1.6 Maximizing Productive Capability
2.2 Failure & Causal Analysis
2.2.1 Original Equipment Manufacturer (OEM) Data
2.2.2 Seeded Fault Analysis
2.2.3 Computerized Fault Modling
2.2.4 Technology Vendor Information
2.2.5 Historical Data Analysis
2.2.6 Postmortem Evaluations
2.2.7 Failure Modes, Effects and Criticality Analysis (FMECA)
2.3 Maintenance Requirements
2.4 Maintenance Concepts
2.4.1 Run-to-Failure (Corrective) Maintenance
2.4.2 Preventive Maintenance (PM)
2.4.3 Condition Based Maintenance (CBM)
2.4.4 Reliability Centered Maintenance (RCM)
2.4.5 Equipment Monitoring Requirements for CBM/RCM

3 Machinery Lubrication
3.1 Introduction
3.2 The Primary Functions of a Lubricant
3.2.1 Carry the Load and Maintain Wear Surface Separation
3.2.1.1 Hydrodynamic Lubrication
3.2.1.2 Elastohydrodynamic Lubrication
3.2.1.3 Boundary Lubrication
3.2.1.4 Hydrostatic Lubrication
3.2.2 Component Cooling
3.2.3 Control Corrosion and Rust
3.2.4 Control Friction and Adhesive Wear
3.2.5 Maintain Oxidation Stability and Neutralize Acids
3.2.6 Breakup and Disperse Carbon Deposits
3.2.7 Control Abrasion and Erosion
3.2.8 Limit Foaming and Emulsions
3.3 Lubricating Oil Types
3.3.1 API Group I - Distilled / Solvent Refined Petroleum Oils
3.3.2 API Group II - Hydrocracked Petroleum Oils
3.3.3 API Group III - Severely Hydrocracked Petroleum Oils
3.3.4 API Group IV - Synthetic Polyalphaofins
3.3.5 API Group V - Synthetic Esters, Diesters, Glycols, Etc.
3.4 Lubricant Additives
3.4.1 Anti-Foam Agents
3.4.2 Anti-Oxidants
3.4.3 Anti-Wear Agents
3.4.4 Corrosion Inhibitors
3.4.5 Detergents and Dispersants
3.4.6 Extreme Pressure (EP) Agents
3.4.7 Friction Modifiers
3.4.8 Pour Point Improvers
3.4.9 Rust Inhibitors
3.4.10 Tackiness Agents
3.4.11 Viscosity Index Improvers (VII)
3.5 Oil Properties and Tests
3.5.1 Aniline Point
3.5.2 Anti-Rust Characteristics
3.5.3 Ash Content from Lubricating Oils
3.5.4 ASTM Color
3.5.5 Copper Corrosion Resistance
3.5.6 Demulsibility
3.5.7 Density & Specific Gravity
3.5.8 Flash and Fire Points
3.5.9 Foaming Characteristics
3.5.10 Hydrolytic Stability Characteristics
3.5.11 Neutralization Number (NN/TAN/TBN)
3.5.12 Oxidation Stability
3.5.13 Pour and Cloud Points
3.5.14 Precipitation Number
3.5.15 Pentane Insolubles Content
3.5.16 Saponification Number (Sap Number)
3.5.17 Sulfur Content
3.5.18 Viscosity Characteristics
3.5.19 Wear-Prevention/Load-Carrying Properties
3.5.20 Lubricant Compatibility Characteristics
3.6 Grease Types
3.6.1 Aluminum Soap & Aluminum Complex Greases
3.6.2 Calcium Soap & Calcium Complex Greases
3.6.3 Lithium Soap & Lithium Complex Greases
3.6.4 Sodium Soap Grease
3.6.5 Organo-Clay Grease
3.6.6 Polyurea & Polyurea Complex Greases
3.6.7 Silica Grease
3.7 Grease Properties and Tests
3.7.1 Grease Consistency
3.7.2 Copper Corrosion Resistance
3.7.3 Dropping Point of Grease
3.7.4 Oil Evaporation & "Oil Bleed"
3.7.5 Grease Pumpability and Slumpability
3.7.6 Oxidation Stability
3.7.7 Water Wash-Out Charactereistics
3.7.8 Wear-Prevention/Load Carrying Properties
3.8 Petroleum Products Tests - Cross-Reference
3.8.1 General Fluids Tests
3.8.2 Grease Properties Tests
3.8.3 Lubricant Properties Tests
3.8.4 Fuel Properties Tests
3.8.5 Bitumen and Wax Tesrts

4 Machinery Systems and Components
4.1 Oil Wetted Components
4.1.1 Journal Bearings
4.1.2 Anti-Friction Bearings
4.1.3 Piston, Ring & Liner Sets
4.1.4 Gears
4.1.5 Spline Couplings
4.1.6 Sprockets and Chains
4.2 Machinery Systems
4.2.1 Industrial Circulating Oil Systems
4.2.2 Central Once-Through Lubricators
4.2.3 General Purpose Bearing Systems
4.2.4 Industrial Machine Tools
4.2.5 Mechanical Presses and Stamping Machines
4.2.6 Gear Systems
4.2.7 Transmission Systems
4.2.8 Hydraulic Systems
4.2.9 Crankcase Systems

5 Fluid Filtration and Purification
5.1 Oil Cleanliness
5.1.1 Steps to Understanding Oil Cleanliness Practice
5.1.2 Filter System Rating
5.2 Filtration System Types
5.2.1 Cartridge Media Filters
5.2.2 Depth/Polishing Media
5.2.3 Porous Metal Strainer
5.2.4 Cyclonic Separator
5.2.5 Electrostatic Filter
5.2.6 Magnetic Filtration
5.2.7 Settling & Sedimentation
5.3 Purification System Types
5.3.1 Electronic Purification Principles
5.3.2 Chemical Media Purification Principles
5.3.3 Water Removal Principles
5.4 Filter Selection Considerations
5.4.1 Improving Particulate Removal
5.4.2 Improving Water Removal

6 Machinery Failure Modes
6.1 Introduction
6.2 General Fluid Problems
6.2.1 Changes in Oil Color
6.2.2 Visible Contaminants in the Oil
6.2.3 Changes in Oil Odor
6.2.4 Changes in Lubricant Consistency
6.2.5 Change in Oil Viscosity
6.2.6 Incorrect Oil Addition
6.3 Contamination Related Failure Modes
6.3.1 Water Contamination
6.3.2 Glycol Contamination
6.3.3 Fuel Dilution
6.3.4 Particulates & Dirt
6.4 Degradation Related Oil Failure Modes
6.4.1 Oxidative Degradation of Petroleum Oils
6.4.2 Degradation of Synthetic Esters
6.4.3 Additive Depletion
6.5 Filter Failure Modes
6.6 Machinery Wear Phases & Failure Modes
6.6.1 Break-In Wear
6.6.2 Normal Wear (Dynamic Equilibrium)
6.6.3 Abnormal Wear Mechanisms and Symptoms
6.6.4 Other Wear/Damage Modes

7 Oil Sampling
7.1 Sample Quality Considerations
7.1.1 Data Variability Concerns
7.1.2 Sample Bottle Kits
7.1.3 Representative Sampling - What Does it Mean?
7.1.4 Representative Analysis - Correlating Test Data to Equipment Condition!
7.2 Taking a Good Oil Sample
7.2.1 Taking a Sample from a Valve
7.2.2 Taking a Sample with a Vacuum Gun
7.2.3 Taking a Sample with a Syringe
7.2.4 Recording Sample Information
7.3 Establishing an Optimum Sample Interval
7.3.1 High Speed Equipment
7.3.2 Medium Speed Equipment
7.3.3 Slow Speed Equipment
7.3.4 Backup and Standby Equipment
7.4 Other Sampling Considerations
7.4.1 Effect of Sampling Location
7.4.2 Effect of Sampling Procedure
7.4.3 Effect of Fluid Maintenance Activities
7.4.4 Effect of Filtration Activities
7.4.5 Effect of Component Changes
7.4.6 Effect of Different End-Item Applications
7.4.7 Effect of Operational Duty-Cycle and Environment
7.4.8 Effect of Auxiliary Oil Reservoirs
7.4.9 Effect of Circulating Fluid Systems
7.4.10 Effect of Bath Lubrication Systems
7.4.11 Effect of Splash Lubrication Systems
7.4.12 Effect of Once-Through Fluid Systems
7.4.13 Effect of Grease Lubrication Systems

8 Condition Monitoring Tests
8.1 Condition Monitoring
8.2 Elemental (Metals) Analysis
8.2.1 Atomic Emission (AE) Spectroscopy
8.2.2 Atomic Absorption (AA) Spectroscopy
8.2.3 X-Ray Fluorescence (XRF) Spectroscopy
8.2.4 Wear Particle Analysis
8.3 Infrared (Molecular) Analysis
8.3.1 Dispersive Infrared Spectroscopy
8.3.2 Fourier Transform Infrared (FT-IR) Spectroscopy
8.3.3 Differences in FT-IR Analyzers
8.3.4 IR In-Line Sensors
8.3.5 IR Analysis of In-Service Oils
8.3.5.1 Water Contamination
8.3.5.2 Fuel Dilution
8.3.5.3 Glycol Contamination
8.3.5.4 Soot Contamination of Motor Oils
8.3.5.5 Petroleum Oil Degradation
8.3.5.6 Ester Basestock Breakdown
8.3.5.7 Additive Depletion
8.3.6 IR Prediction of Oil Properties
8.4 Particulate Contamination Analysis
8.5 Other Condition Tests
8.5.1 Water Contamination by Karl Fischer Titration
8.5.2 Anti-Oxidant Condition by RULER®
8.5.3 Gas Chromatography
8.5.4 Diesel Fuel Dilution by Fuel Sniffer
8.5.5 Glycol Contamination Measurement
8.5.6 Changes in Grease Consistency
8.5.7 On-Site Analysis Test Kit

9 Data Interpretation
9.1 A Statistical Data Analysis Paradigm
9.2 Preparing Test Data for Analysis
9.3 Trending Test Data
9.3.1 Traditional Trending Technique
9.3.2 Adaptive Data Trending
9.3.3 Adaptive Trending Rules
9.4 General Purpose Data Interpretation Criteria
9.4.1 Condition (Fault) Indicator Definition
9.4.2 Condition Indicator Development
9.4.3 Improving Condition Indicator Reliability
9.4.4 Equipment Specific Considerations
9.4.5 Common Elements and Their Sources
9.5 Statistically Based Alarm Limits
9.5.1 Alarm Limit Calculation
9.5.2 Alarm Limit Reliability Considerations
9.5.3 Overall Equipment Condition Status

10 Automation - Expert Systems
10.1 Computerized Maintenance Management System (CMMS)
10.1.1 System Database
10.1.2 Oil Analysis Application
10.1.3 Management Functions
10.1.4 Computer Platform
10.2 Expert Systems
10.2.1 Expert Language Development
10.3 Oil Data Evaluation Strategy
10.3.1 Raw Data Preparation
10.3.2 Data Conversion Procedure
10.3.2 Diagnostic Evaluation
10.3.4 Business Response Evaluation
10.3.5 Sample Analysis Reporting

11 Establishing an Oil Analysis Program
11.1 Oil Analysis Program Responsibilities
11.1.1 Program Mandate
11.1.2 New Oil Quality Control
11.1.3 Used Oil Condition Monitoring
11.1.4 Equipment Wear and Condition Monitoring
11.2 Estimating Realistic Benefits
11.2.1 Effect of Program Mandate
11.2.2 Effect of Operational Policies
11.2.3 Effect of Maintenance Policies
11.3 Calculating Economic Benefits
11.4 Selecting Machine Tests and Sample Intervals
11.4.1 Equipment Considerations
11.4.2 Diesel/Automotive Engines and Ancillaries
11.4.3 Aircraft Gas Turbine Engines and Ancillaries
11.4.4 Industrial Turbine Equipment
11.4.5 Hydraulic Fluid Power Systems
11.4.6 Manufacturing Machinery
11.5 Machinery Testing Services
11.5.1 Low Sample Volume
11.5.2 Medium Sample Volume
11.5.3 High Sample Volume
11.6 Quality Assurance & Control
11.6.1 Measurement and Uncertainty
11.6.2 Measurements on a Representative Oil Sample
11.6.3 The Calibration Standard
11.6.4 Ensuring Quality Test Data
11.6.5 Data Handling and Integrity
11.6.6 On Forward

Glossary
Index

As with prior editions, the third edition is intended as a reference for equipment maintenance managers, supervisors and technicians. It provides a general description of oil-lubricated machinery, machinery fluids and filtration technologies, condition monitoring technology and the essential procedures for establishing a reliable equipment lubricant monitoring program. Management issues include developing effective condition indicators, calculating alarm limits, and estimating realistic program benefits.

Since the publishing of the second edition in 1998, equipment maintenance and monitoring practices have evolved substantially. Maintenance managers increasingly use condition-data and other operational parameters to make decisions concerning "what maintenance to perform and when to perform it". Condition monitoring is a crucial element in Condition Based Maintenance (CBM) and Reliability Centered Maintenance (RCM) programs.

Since the last edition, advancements in maintenance philosophy and new developments in the industry have generated a vast array of condition monitoring instrumentation and sensors, all of which improve the quality of machine and lubricant data. To describe all of these developments would be impractical. Instead, this book focuses on key oil condition monitoring methods, how to develop a general-purpose data interpretation procedure applicable for use with laboratory instrumentation, field instruments, and on-line sensors, and a means to overcome the increasing data analysis burden.

The book also emphasizes the importance of performing failure modes, effects and criticality analysis and understanding the impact maintenance policies have on monitoring effectiveness and benefits. Typical solutions for common problems and the support needed to establish a successful program are discussed.