Vista Previa API 580 2002

8/13/2019 Vista Previa API 580 2002

1/11

Risk-based Inspection

API RECOMMENDED PRACTICE 580FIRST EDITION, MAY 2002


2/11


3/11


Downstream Segment

API RECOMMENDED PRACTICE 580FIRST EDITION, MAY 2002


4/11

SPECIAL NOTES

API publications necessarily address problems of a general nature. With respect to partic-

ular circumstances, local, state, and federal laws and regulations should be reviewed.

API is not undertaking to meet the duties of employers, manufacturers, or suppliers to

warn and properly train and equip their employees, and others exposed, concerning health

and safety risks and precautions, nor undertaking their obligations under local, state, or fed-

eral laws.

Information concerning safety and health risks and proper precautions with respect to par-

ticular materials and conditions should be obtained from the employer, the manufacturer or

supplier of that material, or the material safety data sheet.

Nothing contained in any API publication is to be construed as granting any right, by

implication or otherwise, for the manufacture, sale, or use of any method, apparatus, or prod-

uct covered by letters patent. Neither should anything contained in the publication be con-

strued as insuring anyone against liability for infringement of letters patent.

Generally, API standards are reviewed and revised, reaffirmed, or withdrawn at least every

five years. Sometimes a one-time extension of up to two years will be added to this review

cycle. This publication will no longer be in effect five years after its publication date as anoperative API standard or, where an extension has been granted, upon republication. Status

of the publication can be ascertained from the API Standards Department [telephone (202)

682-8000]. A catalog of API publications and materials is published annually and updated

quarterly by API, 1220 L Street, N.W., Washington, D.C. 20005, www.api.org.

This document was produced under API standardization procedures that ensure appropri-

ate notification and participation in the developmental process and is designated as an API

standard. Questions concerning the interpretation of the content of this standard or com-

ments and questions concerning the procedures under which this standard was developed

should be directed in writing to the director, Standards Department, American Petroleum

Institute, 1220 L Street, N.W., Washington, D.C. 20005, [email protected]. Requests for

permission to reproduce or translate all or any part of the material published herein should

also be addressed to the general manager.

API standards are published to facilitate the broad availability of proven, sound engineer-ing and operating practices. These standards are not intended to obviate the need for apply-

ing sound engineering judgment regarding when and where these standards should be

utilized. The formulation and publication of API standards is not intended in any way to

inhibit anyone from using any other practices.

Any manufacturer marking equipment or materials in conformance with the marking

requirements of an API standard is solely responsible for complying with all the applicable

requirements of that standard. API does not represent, warrant, or guarantee that such prod-

ucts do in fact conform to the applicable API standard.

All rights reserved. No part of this work may be reproduced, stored in a retrieval system, or

transmitted by any means, electronic, mechanical, photocopying, recording, or otherwise,

without prior written permission from the publisher. Contact the Publisher,

API Publishing Services, 1220 L Street, N.W., Washington, D.C. 20005.

Copyright 2002 American Petroleum Institute


5/11

FOREWORD

This recommended practice is intended to provide guidance on developing a risk-based

inspection (RBI) program on fixed equipment and piping in the hydrocarbon and chemical

process industries. It includes:

What is RBI

What are the key elements of RBI

How to implement a RBI program

It is based on knowledge and experience of engineers, inspectors, risk analysts and other

personnel in the hydrocarbon and chemical industry.

RP 580 is intended to supplement API 510 Pressure Vessel Inspection Code

, API 570 Pip-

ing Inspection Code

and API 653 Tank Inspection, Repair, Alteration and Reconstruction

.

These API inspection codes and standards allow an owner/user latitude to plan an inspection

strategy and increase or decrease the code designated inspection frequencies based on the

results of a RBI assessment. The assessment must systematically evaluate both the probabil-

ity of failure and the associated consequence of failure. The probability of failure assessment

must be based on all forms of deterioration that could reasonably be expected to affect the

piece of equipment in the particular service. Refer to the appropriate code for other RBIassessment requirements. RP 580 is intended to serve as a guide for users in properly per-

forming such a RBI assessment.

The information in this recommended practice does not constitute and should not be con-

strued as a code of rules, regulations, or minimum safe practices. The practices described in

this publication are not intended to supplant other practices that have proven satisfactory, nor

is this publication intended to discourage innovation and originality in the inspection of

hydrocarbon and chemical facilities. Users of this recommended practice are reminded that

no book or manual is a substitute for the judgment of a responsible, qualified inspector or

engineer.

API publications may be used by anyone desiring to do so. Every effort has been made by

the Institute to assure the accuracy and reliability of the data contained in them; however, the

Institute makes no representation, warranty, or guarantee in connection with this publication

and hereby expressly disclaims any liability or responsibility for loss or damage resultingfrom its use or for the violation of any federal, state, or municipal regulation with which this

Publication may conflict.

Suggested revisions are invited and should be submitted to the director, Standards Depart-

ment, American Petroleum Institute, 1220 L Street, N.W., Washington D.C. 20005, stan-

[email protected].

iii


6/11


7/11

CONTENTS

Page

1 INTRODUCTION, PURPOSE AND SCOPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.1 Purpose. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.2 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1.3 Target Audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

2 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2.1 Referenced Publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2.2 Other References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

3 DEFINITIONS AND ACRONYMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

3.1 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

3.2 Acronyms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

4 BASIC CONCEPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74.1 What is Risk? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

4.2 Risk Management and Risk Reduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

4.3 The Evolution of Inspection Intervals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

4.4 Inspection Optimization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

4.5 Relative Risk vs. Absolute Risk. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

5 INTRODUCTION TO RISK-BASED INSPECTION. . . . . . . . . . . . . . . . . . . . . . . . . . 8

5.1 Consequence and Probability for Risk-Based Inspection. . . . . . . . . . . . . . . . . . . 8

5.2 Types of RBI Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

5.3 Precision vs. Accuracy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

5.4 Understanding How RBI Can Help to Manage Operating Risks . . . . . . . . . . . . 11

5.5 Management of Risks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

5.6 Relationship Between RBI and Other Risk-Based and Safety Initiatives . . . . . 125.7 Relationship with Jurisdictional Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . 13

6 PLANNING THE RBI ASSESSMENT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

6.1 Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

6.2 Establishing Objectives and Goals of a RBI Assessment . . . . . . . . . . . . . . . . . . 13

6.3 Initial Screening. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

6.4 Establish Operating Boundaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

6.5 Selecting a Type of RBI Assessment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

6.6 Estimating Resources and Time Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

7 DATA AND INFORMATION COLLECTION FOR RBI ASSESSMENT . . . . . . . 17

7.1 RBI Data Needs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

7.2 Data Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

7.3 Codes and StandardsNational and International. . . . . . . . . . . . . . . . . . . . . . . 18

7.4 Sources of Site Specific Data and Information . . . . . . . . . . . . . . . . . . . . . . . . . . 18

8 IDENTIFYING DETERIORATION MECHANISMS AND FAILURE MODES . . 19

8.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

8.2 Failure and Failure Modes for Risk-Based Inspection . . . . . . . . . . . . . . . . . . . . 19

8.3 Deterioration Mechanisms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

8.4 Other Failures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

v


8/11

Page

9 ASSESSING PROBABILITY OF FAILURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

9.1 Introduction to Probability Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

9.2 Units of Measure in the Probability of Failure Analysis. . . . . . . . . . . . . . . . . . . 20

9.3 Types of Probability Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

9.4 Determination of Probability of Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

10 ASSESSING CONSEQUENCES OF FAILURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

10.1 Introduction to Consequence Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

10.2 Types of Consequence Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

10.3 Units of Measure in Consequence Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

10.4 Volume of Fluid Released . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

10.5 Consequence Effect Categories. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

11 RISK DETERMINATION, ASSESSMENT AND MANAGEMENT. . . . . . . . . . . . 26

11.1 Purpose. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

11.2 Determination of Risk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

11.3 Risk Management Decisions and Acceptable Levels of Risk. . . . . . . . . . . . . . . 2811.4 Sensitivity Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

11.5 Assumptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

11.6 Risk Presentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

11.7 Establishing Acceptable Risk Thresholds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

11.8 Risk Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

12 RISK MANAGEMENT WITH INSPECTION ACTIVITIES . . . . . . . . . . . . . . . . . . 30

12.1 Managing Risk by Reducing Uncertainty Through Inspection . . . . . . . . . . . . . 30

12.2 Identifying Risk Management Opportunities from RBI

and Probability of Failure Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

12.3 Establishing an Inspection Strategy Based on Risk Assessment . . . . . . . . . . . . 31

12.4 Managing Risk with Inspection Activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

12.5 Managing Inspection Costs with RBI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3212.6 Assessing Inspection Results and Determining Corrective Action . . . . . . . . . . 32

12.7 Achieving Lowest Life Cycle Costs with RBI . . . . . . . . . . . . . . . . . . . . . . . . . . 32

13 OTHER RISK MITIGATION ACTIVITIES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

13.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

13.2 Equipment Replacement and Repair. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

13.3 Evaluating Flaws for Fitness-for- Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

13.4 Equipment Modification, Redesign and Rerating. . . . . . . . . . . . . . . . . . . . . . . . 33

13.5 Emergency Isolation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

13.6 Emergency Depressurizing/De-inventory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

13.7 Modify Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

13.8 Reduce Inventory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

13.9 Water Spray/Deluge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

13.10 Water Curtain. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

13.11 Blast-Resistant Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

13.12 Others. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

vi


9/11

Page

14 REASSESSMENT AND UPDATING RBI ASSESSMENTS . . . . . . . . . . . . . . . . . . 34

14.1 RBI Reassessments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

14.2 Why Conduct a RBI Reassessment? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

14.3 When to Conduct a RBI Reassessment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

15 ROLES, RESPONSIBILITIES, TRAINING AND QUALIFICATIONS . . . . . . . . . 35

15.1 Team Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

15.2 Team Members, Roles & Responsibilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

15.3 Training and Qualifications For RBI Application. . . . . . . . . . . . . . . . . . . . . . . . 36

16 RBI DOCUMENTATION AND RECORD-KEEPING . . . . . . . . . . . . . . . . . . . . . . . 37

16.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

16.2 RBI Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

16.3 RBI Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

16.4 Time Frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

16.5 Assignment of Risk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

16.6 Assumptions Made to Assess Risk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3716.7 Risk Assessment Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

16.8 Mitigation and Follow-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

16.9 Codes, Standards and Government Regulations. . . . . . . . . . . . . . . . . . . . . . . . . 38

APPENDIX A DETERIORATION MECHANISMS . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Figures

1 Management of Risk Using RBI. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2 Risk Plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

3 Continuum of RBI Approaches. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

4 Risk-based Inspection Planning Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

5 Example Event Tree . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

6 Example Risk Matrix Using Probability and Consequence Categories

to Display Risk Rankings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

7 Risk Plot when Using Quantitative or Numeric Risk Values. . . . . . . . . . . . . . . . . 30

Tables

1 Thinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

2 Stress Corrosion Cracking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

3 Metallurgical and Environmental Failures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

4 Mechanical Failures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

vii


10/11


11/11

1


1 Introduction, Purpose and Scope

1.1 PURPOSE

The purpose of this document is to provide users with the

basic elements for developing and implementing a risk-based

inspection (RBI) program. The methodology is presented in a

step-by-step manner to the maximum extent practicable.

Items covered are:

a. An introduction to the concepts and principles of risk-

based inspection for risk management; and

b. Individual sections that describe the steps in applying

these principles within the framework of the RBI process:

1. Planning the RBI Assessment.

2. Data and Information Collection.

3. Identifying Deterioration Mechanisms and Failure

Modes.

4. Assessing Probability of Failure.

5. Assessing Consequence of Failure.

6. Risk Determination, Assessment and Management.

7. Risk Management with Inspection Activities.

8. Other Risk Mitigation Activities.

9. Reassessment and Updating.

10. Roles, Responsibilities, Training and Qualifications.

11. Documentation and record-keeping.

The expected outcome from the application of the RBI pro-cess should be the linkage of risks with appropriate inspec-

tion or other risk mitigation activities to manage the risks.

The RBI process is capable of generating:

a. A ranking by risk of all equipment evaluated.

b. A detailed description of the inspection plan to be

employed for each equipment item, including:

1. Inspection method(s) that should be used (e.g., visual,

UT, Radiography, WFMT).

2. Extent of application of the inspection method(s) (e.g.,

percent of total area examined or specific locations).

3. Timing of inspections/examinations.4. Risk management achieved through implementation of

the inspection plan.

c. A description of any other risk mitigation activities (such

as repairs, replacements or safety equipment upgrades).

d. The expected risk levels of all equipment after the inspec-

tion plan and other risk mitigation activities have been

implemented.

1.1.1 Key Elements of a RBI Program

Key elements that should exist in any RBI program are:

a. Management systems for maintaining documentation, per-

sonnel qualifications, data requirements and analysis updates.

b. Documented method for probability of failure

determination.

c. Documented method for consequence of failure

determination.

d. Documented methodology for managing risk through

inspection and other mitigation activities.

However, all the elements outlined in 1.1 should be ade-

quately addressed in RBI applications, in accordance with the

recommended practices in this document.

1.1.2 RBI Benefits and Limitations

The primary work products of the RBI assessment and

management approach are plans that address ways to manage

risks on an equipment level. These equipment plans highlight

risks from a safety/health/environment perspective and/or

from an economic standpoint. In these plans, cost-effective

actions for risk mitigation are recommended along with the

resulting level of risk mitigation expected.

Implementation of these plans provides one of the follow-

ing:

a. An overall reduction in risk for the facilities and equip-

ment assessed.b. An acceptance/understanding of the current risk.

The RBI plans also identify equipment that does not

require inspection or some other form of mitigation because

of the acceptable level of risk associated with the equipments

current operation. In this way, inspection and maintenance

activities can be focused and more cost effective. This often

results in a significant reduction in the amount of inspection

data that is collected. This focus on a smaller set of data

should result in more accurate information. In some cases, in

addition to risk reductions and process safety improvements,

RBI plans may result in cost reductions.

RBI is based on sound, proven risk assessment and manage-ment principles. Nonetheless, RBI will not compensate for:

a. Inaccurate or missing information.

b. Inadequate designs or faulty equipment installation.

c. Operating outside the acceptable design envelope.

d. Not effectively executing the plans.

e. Lack of qualified personnel or teamwork.

f. Lack of sound engineering or operational judgment.

Documents

Vista Previa API 580 2002