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1Introduction

This chapter introduces the need for process equipm ent failure rate data, defin es the scopeand organization of this book and the data it contains, and explains how to the use thebook.

1.1 BackgroundThe Chemical Process Industry (CPI) uses various quantitative and qualitative techniquesto assess the reliability and risk of process equipment, process systems, and chemicalmanufacturing operations. These techniques identify the interactions of equipment, sys-tems, and persons that have potentially undesirable consequences. In the case of reliabilityanalyses, the undesirable consequences (e.g., plant shutdown, excessive downtime, orproduction of off-specification product) are those incidents which reduce system prof-itability through loss of production and increased maintenance costs. In the case of riskanalyses, the primary concerns are human injuries, environmental impacts, and systemdamage caused by occurrence of fires, explosions, toxic material releases, and relatedhazards. Quantification of risk in terms of the severity of the consequences and thelikelihood of occurrence provides the manager of the system with an important decision-making tool. By using the results of a quantitative risk analysis, we are better able toanswer such questions as, "Which of several candidate systems poses the least risk?" "Arerisk reduction modifications necessary?" and "What modifications would be most effec-tive in reducing risk?"In performing such a risk analysis, the risk analyst first uses hazard identificationtechniques such as those presented in Guidelines for Hazard Evaluation Procedures(henceforth, HEP Guidelines) such as Failure Modes and Effects Analysis (FMEA) orHazard and Operability Studies (HAZOP) to identify the incidents or combinations ofincidents that must occur to create a given consequence. The analyst may also usetechniques such as fault tree analysis or event tree analysis to further define the particularprocess or equipm ent failures that will result in the incidents of concern. Usin g procedurescontained in Guidelines for Chemical Process Quantitative Risk Analysis (henceforth,CPQRA Guidelines), the severity of the consequences is then evaluated by consideringthe environm ent in wh ich the incident occurs and, if necessary, applying techniques suchas dispersion, blast, or heat radiation modeling. To evaluate the likelihood of occurrenceof the incident, the analyst must know how frequently the contributory failure incidentsare likely to occur. Consequently, failure rate data for the equipment involved in theincidents is essential to the risk analysis.

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1.2 Guidelines Purpose, Scope, and Organization7.2.7 PurposeThe primary purpose of this book is to provide the engineer and risk analyst with failurerate data needed to perform a CPQRA. Consequently, the book contains easily accessibledata in the CCPS Generic Failure Rate Data Base, information on several availablegeneric data resources, and procedures to develop failure rate data using information fromthe plant and process being studied. Another purpose is to present an approach thatcoordinates the collection of raw plant data, their conversion into plant-specific failuredata, and their storage using a CPI-oriented taxonomy. This approach will allow futuredata generated by chemical process facilities to be added to the CCPS Generic FailureRate Data Base. The book provides specifications for the transfer of data. It is hoped thisapproach and standardization will stimulate the chemical processing industry to generateand transfer failure rate data to CCPS for industry use. It is also expected that this bookand the CCPS Taxonomy will be revised and updated when sufficient new data becomeavailable. Finally, this Guidelines is written to help engineers and analysts develop anunderstanding of the derivation, usefulness, and limitation of failure rate data so they canform better judgments about the use of data.7.2.2 ScopeThe data presented in this book are characterized as equipment failures per 106 operatinghours for time-related failure rates and failures per 103 demands for demand-relatedfailure rates. These rates are given for some common CPI equipment. Equipment usedsolely to transport chemicals is not covered in this book. The cause of equipment failures,the means to improve reliability and the "most" reliable equipment are not addressed.Other types of failure rate data, such as predicted values or estimated values using expertopinion or the Delphi technique, are addressed in the CPQRA Guidelines. Sources ofcommon cause/mode failure data are not addressed. Human error rates, though necessaryfor CPQRAs, and human performance in CPI facilities will be addressed in a forthcomingGuidelines. Figure 1.1 illustrates the scope of this book in relation to the CPQRA Guide-lines. In preparing this book, the CCPS Subcommittee tried to review all publishedsources of available generic equipment reliability and failure rate data, including re-liability studies, published research works, reliability data banks, or government reportsthat contained information gathered from chemical process, nuclear, offshore oil, andfossil fuel industries around the world. An industry survey was conducted to solicitunpublished data.7.2.3 OrganizationThe sections of this book and their contents are: Chapter 1Introduction: Discusses the need for process equipment failure rate data,

describes the purpose, scope and organization of this book, and explains how to the useit.

Chapter 2Origin, Use, and Limitations of Failure Rate Data: Explains the mean-ing of generic and plant-specific data, the difference between time-related and demand-

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related failures, issues of confidence and tolerance, what is captured as an equipmentfailure, the failure model used and the role of the taxonomy. Chapter 3CCPS Taxonomy: Explains the CCPS taxonomy. Discusses the rationaleand process for its development and the factors considered in its construction. Chapter 4Data Bases, Sources, and Studies: Summarizes and characterizes severalgeneric data resources available to risk analysts and process engineers in the CPI. It

includes a discussion of the resource search and selection process and the presentationformat for the information on resources. Chapter 5CCPS Generic Failure Rate Data Base: Contains tables of generic

process equipment reliability data that are structured by the CCPS Taxonomy. The dataare extracted from data resources in Chapter 4. The chapter includes a discussion of theselection, treatment, and presentation of the data in the Tables.

Chapter 6Collection and Conversion of Plant-Specific Data: Describes the typeofdata required and their treatment to develop a plant-specific data set suitable for use oraggregation with other data. Chapter 7Failure Rate Data Transfer: Provides a form to facilitate the transfer of

plant-specific data to the CCPS Data Base or to combine it with other generic data. Chapter 8Supplemental References: A collection of references that describe datacollection, analysis, and application techniques but, in general, do not contain re-liability data. Appendix ACCPS Taxonomy: The full CCPS Taxonomy for process equipmentfailure rate data. Appendix BEquipment Index: Allows the user to determine the taxonomy locationfor equipment types familiar to the CPI. Appendix CMatrix of Data Elements in Each Data Resource: Presents the userwith a more detailed summary of the data elements available from each data resource in

Chapter 4. Appendix DUnreviewed Data Bases, Data Sources, andStudies: Provides a list ofdata resources that were uncovered too late for review.

1.3 Use of This GuidelinesIt is recommended as a first step that the user of the book review the entire volume tobecome familiar with the various aspects of equipment failure rates that are presented.This can provide a better understanding of the derivation, value, and limitations of genericdata. Beyond this, the volume is structured to assist the reader in one or more of threebasic tasks. These tasks are: locating generic data for use in a CPQRA; finding potential data resources for additional data or more information; and developing a system for collecting and recording in-plant reliability data.

To find generic data in this book for use in a CPQRA, the reader should first locatethe taxonomy number for the equipment under study by referring to Appendix B, Equip-ment Index. This index shows the taxonomy number for various types of commonly usedequipment. Knowing the taxonomy number, the reader can consult the Index of FilledData Cells (Table 5.2) to determine if the data exist in Chapter 5. Alternatively, the user

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Figure 1.1. Process equipment reliability data: data sources, dataflow, and data use.

R E C O R D S F R O M O N E P L A N T

F L O W , P I P I N G , A N DI N S T R U M E N T A T I O ND R A W I N G S

O P E R A T I N G A N DM A I N T E N A N C EP R O C E D U R E S

I N D U S T R Y G E N E R I CD A T A

P L A N TR E C O R D S R E L E V A N TD A T AR A W D A T AC O L L E C T I O NA N DR E V I E W R A W D A T AC L A S S I F I C A T I O NA N D S O R T I N G

S O R T E DD A T A

G E N E R I CD A T A S O U R C ES E L E C T I O NS E L E C T E DG E N E R I CD A T AS O U R C E S

D A T AR E Q U I R E -M E N T S

E Q U I P M E N T L I S T S

O P E R A T I ML O G S ,R E P O R T S

I R R E L E V A N TR E C O R D S

R E C O R D SF R O MO T H E RP L A N T SP E R M A N E N T T R A C E A B L ER A W D A T A & P R O C E S S F IL E S

G U I D E L I N E S F O R P R O C E S SE Q U I P M E N T R E L I A B I L I T Y D A T A

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G E N E R I CD A T AE X T R A C T I O NC C P SG E N E R I CD A T A B A S EP R O T O C O L

G E N E R I C R E L I A B I L I T Y D A T AC C P ST A X O N O M Y

I N T E G R A T I O N A N DA G G R E G A T IO N O FP L A N T - S P E C I F I CA N D G E N E R I CD A T A ID A T A C L A S S -I F I C A T I O N A N DS O R T I N G

C C P S G E N E R I CD A T A B A S EC C P SD A T A S H E E T S

C O M P U T E RA C C E S S I B L ED A T A B A S E( F u t u r e )

R A W D A T AA N A L Y S I SA N DR E D U C T I O N

R E D U C E DD A T A F A I L U R E R A T EA N DP R O B A B I L I T YC A L C U L A T I O N S

P L A N T - S P E C I F I CD A T AE X P E R TO P I N I O N

A N A L Y S I SD A T A B A S E I N T E G R A T I O NA N DA G G R E G A T I O NO F D A T A

G E N E R I CD A T A

P R E D I C T E DD A T A

A N A L Y S I S C o m p o n e n t P o p u l a t i o n s D e m a n d C o u n ts E x p o s u r e T im e s F a i l u r e C o u n t sREDUCTION F a i l u r e M o d e l a n dP a r a m e t e r s

PLANTSPECIFICRELIABILITY D A T A T i m e R e l a t e d F a i l u r e R a t e s D e m a n d R e la te d F a i l u r e R a t e s E r r o r B o u n d s

C O M P A N Y ,C O M M U N I T Y ,R E G U L A T O R Y A N DO T H E R S P E C I A LR E P O R T SU I D E L I N E S F O R C H E M IC A L P R O C E S SQ U A N T IT A T I V E R I SK A N A L Y S I SC P Q R A

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may look in the Chapter 5 Data Tables once the taxonomy number has been located.Readers who require additional sources of data should refer to the indexes at the beginningof each resource section in Chapter 4 (Sections 4.3, 4.4, 4.5, 4.6, 4.7, or 4.8). Theseindexes help the reader identify the most useful resources in terms of the type and extentof data presented. Appendix C is also useful, as it provides additional detail about thesedata resources.When plant-specific data are required, Chapter 6 discusses how to collect and treatthe data so that the resulting failure rates can be used in a CPQRA or be combined with thedata in the CCPS Generic Failure Rate Data Base. Chapter 7 provides a form that can beused to transfer these data to CCPS's Generic Failure Rate Data Base.