Piping Inspection Code

Inspection, Repair, Alteration, and Rerating of In-service Piping Systems

API 570

SECOND EDITION, OCTOBER 1998 ADDENDUM 1, FEBRUARY 2000

ADDENDUM 2, DECEMBER 2001

ADDENDUM 3, AUGUST 2003

ADDENDUM 4, JUNE 2006

Piping Inspection Code

Inspection, Repair, Alteration, and Rerating of In-service Piping Systems

Downstream Segment

API 570

SECOND EDITION, OCTOBER 1998 ADDENDUM 1, FEBRUARY 2000

ADDENDUM 2, DECEMBER 2001

ADDENDUM 3, AUGUST 2003

ADDENDUM 4, JUNE 2006

SPECIAL NOTES

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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.

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00 should be directed in writing to the director of the Standards Department, American Petro- leum Institute, 1220 L Street, N.W., Washington, D.C. 20005. Requests for permission to reproduce or translate all or any part of the material published herein should also be addressed to the director.

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Copyright © 1998, 2000, 2001, 2003, 2006 American Petroleum Institute

FOREWORD

It is the intent of API to keep this publication up to date. All piping system owners and operators are invited to report their experiences in the inspection and repair of piping sys- tems whenever such experiences may suggest a need for revising or expanding the practices set forth in API 570.

This edition of API 570 supersedes all previous editions of API 570, Piping Inspection Code: Inspection, Repair, Alteration, and Rerating of In-service Piping Systems. Each edi- tion, revision, or addenda to this API standard may be used beginning with the date of issu- ance shown on the cover page for that edition, revision, or addenda. Each edition, revision, or addenda, to this API standard becomes effective six months after the date of issuance for equipment that is rerated, reconstructed, relocated, repaired, modified (altered), inspected, and tested per this standard. During the six-month time between the date of issuance of the edition, revision, or addenda and the effective date, the user shall specify to which edition, revision, or addenda, the equipment is to be, rerated, reconstructed, relocated, repaired, mod- ified (altered), inspected and tested.

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 resulting from its use or for the violation of any federal, state, or municipal regulation with which this publication may conflict.

1. Suggested revisions are invited and should be submitted to the director of the Standards Department, American Petroleum Institute, 1220 L Street, N.W., Washington, D.C. 20005, standard@api.org.

   
   

   iii

   
   

   CONTENTS

   
   

   Page

   1. SCOPE 1-1

      1. General Application 1-1

      2. Specific Applications 1-1

      3. Fitness-for-service 1-1

         2 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 01

         3 DEFINITIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 06

         1. OWNER/USER INSPECTION ORGANIZATION 4-1

            1. General 4-1

            2. API Authorized Piping Inspector Qualification and Certification 4-1

               4.3 Responsibilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 06

         2. INSPECTION AND TESTING PRACTICES 5-1

            1. Risk-Based Inspection 5-1

               
               

               5.2 5.3	Preparation 5-1 Inspection for Specific Types of Corrosion and Cracking 5-1	01
               5.4	Types of Inspection and Surveillance 5-6
               5.5	Thickness Measurement Locations 5-7	01
               5.6	Thickness Measurement Methods 5-8
               5.7	Pressure Testing of Piping Systems 5-8	01
               5.8	Material Verification and Traceability 5-9	00
               5.9	Inspection of Valves 5-9
               5.10	Inspection of Welds In-service 5-10	06
               5.11	Inspection of Flanged Joints 5-10

         3. FREQUENCY AND EXTENT OF INSPECTION 6-1

         6.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1 03

         1. Piping Service Classes 6-1

         2. Inspection Intervals 6-2

         3. Extent of Visual External and CUI Inspections . . . . . . . . . . . . . . . . . . . . . . . . . 6-2 03

         4. Extent of Thickness Measurement Inspection 6-2

         5. Extent of Small-Bore Auxiliary Piping, and

         Threaded-Connections Inspections 6-3

         1. INSPECTION DATA EVALUATION, ANALYSIS, AND RECORDING 7-1

            
            

            7.1	Corrosion Rate Determination 7-1	01
            7.2	Maximum Allowable Working Pressure Determination 7-1
            7.3	Retirement Thickness Determination 7-2	06
            7.4	Assessment of Inspection Findings 7-2	01
            7.5	Piping Stress Analysis 7-2
            7.6	Reporting and Records for Piping System Inspection 7-4	01

            
            

         2. REPAIRS, ALTERATIONS, AND RERATING OF PIPING SYSTEMS 8-1

            8.1 Repairs and Alterations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1 06

            8.2 Welding and Hot Tapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-2 06

            8.3 Rerating 8-3

            v

            Page

         3. INSPECTION OF BURIED PIPING 9-1

            1. Types and Methods of Inspection 9-1

            2. Frequency and Extent of Inspection 9-2

            3. Repairs to Buried Systems 9-3

            4. Records 9-3

         APPENDIX A APPENDIX B

         INSPECTOR CERTIFICATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1 06

         TECHNICAL INQUIRIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1 06

         APPENDIX C EXAMPLES OF REPAIRS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1 APPENDIX D EXTERNAL INSPECTION

         CHECKLIST FOR PROCESS PIPING. . . . . . . . . . . . . . . . . . . . . . . . . D-1

         
         

         Figures

         5-1 Typical Injection Point Piping Circuit 5-2

         C-1 Encirclement Repair Sleeve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1

         C-2 Small Repair Patches. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-2

         
         

         Tables

         1. Recommended Maximum Inspection Intervals . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3 03

         2. Recommended Extent of CUI Inspection Following Visual Inspection 6-3

         7-1 Two Examples of the Calculation of Maximum Allowable Working Pressure (MAWP) Illustrating the Use of the Corrosion

         Half-Life Concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3 01

         9-1 Frequency of Inspection for Buried Piping Without Effective

         Cathodic Protection 9-2

         
         

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         Piping Inspection Code—Inspection, Repair, Alteration, and Rerating of In-service Piping Systems

         
         

2. Scope

1. GENERAL APPLICATION

   1. Coverage

      API 570 covers inspection, repair, alteration, and rerat- ing procedures for metallic piping systems that have been in-service.

   2. Intent

      API 570 was developed for the petroleum refining and chemical process industries but may be used, where practi- cal, for any piping system. It is intended for use by organi- zations that maintain or have access to an authorized inspection agency, a repair organization, and technically qualified piping engineers, inspectors, and examiners, all as defined in Section 3.

   3. Limitations

API 570 shall not be used as a substitute for the original construction requirements governing a piping system before it is placed in-service; nor shall it be used in conflict with any prevailing regulatory requirements.

1. SPECIFIC APPLICATIONS

   1. Included Fluid Services

      Except as provided in 1.2.2, API 570 applies to piping sys- tems for process fluids, hydrocarbons, and similar flammable or toxic fluid services, such as the following:

      1. Raw, intermediate, and finished petroleum products.

      2. Raw, intermediate, and finished chemical products.

      3. Catalyst lines.

      4. Hydrogen, natural gas, fuel gas, and flare systems.

      5. Sour water and hazardous waste streams above threshold limits, as defined by jurisdictional regulations.

      6. Hazardous chemicals above threshold limits, as defined by jurisdictional regulations.

   2. Excluded and Optional Piping Systems

      The fluid services and classes of piping systems listed below are excluded from the specific requirements of API 570 but may be included at the owner’s or user’s (owner/user’s) option.

      1. Fluid services that are excluded or optional include the following:

         1. Hazardous fluid services below threshold limits, as defined by jurisdictional regulations.

         2. Water (including fire protection systems), steam, steam-condensate, boiler feed water, and Category D fluid services, as defined in ASME B31.3.

      2. Classes of piping systems that are excluded or optional are as follows:

         1. Piping systems on movable structures covered by juris- dictional regulations, including piping systems on trucks, ships, barges, and other mobile equipment.

         2. Piping systems that are an integral part or component of rotating or reciprocating mechanical devices, such as pumps, compressors, turbines, generators, engines, and hydraulic or pneumatic cylinders where the primary design considerations and/or stresses are derived from the functional requirements of the device.

         3. Internal piping or tubing of fired heaters and boilers, including tubes, tube headers, return bends, external crossovers, and manifolds.

         4. Pressure vessels, heaters, furnaces, heat exchangers, and other fluid handling or processing equipment, includ- ing internal piping and connections for external piping.

         5. Plumbing, sanitary sewers, process waste sewers, and storm sewers.

         6. Piping or tubing with an outside diameter not exceed- ing that of NPS 1/2.

         7. Nonmetallic piping and polymeric or glass-lined piping.

      
      

2. FITNESS-FOR-SERVICE

This inspection code recognizes fitness-for-service con- cepts for evaluating in-service degradation of pressure con- 01

taining components. API RP 579 provides general

requirements and detailed assessment procedures for specific types of degradation that are referenced in this code.

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