Heat Treatment Services—Continuous Line for Equipment Used in the Petroleum and Natural Gas Industry

API STANDARD 20N

FIRST EDITION, AUGUST 2019

Special Notes

API publications necessarily address problems of a general nature. With respect to particular circumstances, local, state, and federal laws and regulations should be reviewed.

Neither API nor any of API's employees, subcontractors, consultants, committees, or other assignees make any warranty or representation, either express or implied, with respect to the accuracy, completeness, or usefulness of the information contained herein, or assume any liability or responsibility for any use, or the results of such use, of any information or process disclosed in this publication. Neither API nor any of API’s employees, subcontractors, consultants, or other assignees represent that use of this publication would not infringe upon privately owned rights.

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 authorities having jurisdiction with which this publication may conflict.

API publications are published to facilitate the broad availability of proven, sound engineering and operating practices. These publications are not intended to obviate the need for applying sound engineering judgment regarding when and where these publications should be used. The formulation and publication of API publications is not intended in any way to inhibit anyone from using any other practices.

Users of this standard should not rely exclusively on the information contained in this document. Sound business,

scientific, engineering, and safety judgment should be used in employing the information contained herein.

Any manufacturer marking equipment or materials in conformity with the marking requirements of an API standard is solely responsible for complying with all the applicable requirements of that standard, and this standard does not limit the responsibility of the manufacturer for ensuring compliance with all applicable requirements of that standard or any API certification program requirements. API does not represent, warrant, or guarantee that such products do, in fact, conform to the applicable API standard.

All rights reserved. No part of this work may be reproduced, translated, 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, 200 Massachusetts Avenue, NW, Suite 1100, Washington, DC 20001-5571.

Copyright © 2019 American Petroleum Institute

ii

Foreword

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 product covered by letters patent. Neither should anything contained in the publication be construed as insuring anyone against liability for infringement of letters patent.

The verbal forms used to express the provisions in this specification are as follows:

• the term “shall” denotes a minimum requirement to conform to the standard;

  
  

• the term “should” denotes a recommendation or that which is advised but not required to conform to the standard;

  
  

• the term “may” is used to express permission or a provision that is optional;

  
  

• the term “can” is used to express possibility or capability.

Informative elements—As used in a standard, “informative” denotes elements that identify the document, introduce its content, and explain its background, development, and its relationship with other documents or provide additional information intended to assist the understanding or use of the document.

Normative elements—As used in a standard, “normative” denotes elements that describe the scope of the document and that set out provisions that are required to implement the standard.

ThisdocumentwasproducedunderAPIstandardizationproceduresthatensureappropriatenotificationandparticipation in the developmental process and is designated as an API standard. Questions concerning the interpretation of the content of this publication or comments and questions concerning the procedures under which this publication was developed should be directed in writing to the Director of Standards, American Petroleum Institute, 200 Massachusetts Avenue, NW, Suite 1100, Washington, DC 20001. Requests for permission to reproduce or translate all or any part of the material published herein should also be addressed to the director.

Generally, API standards are reviewed and revised, reaffirmed, or withdrawn at least every five years. A one-time extension of up to two years may be added to this review cycle. 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 by API, 200 Massachusetts Avenue, NW, Suite 1100, Washington, DC 20001.

Suggested revisions are invited and should be submitted to the Standards Department, API, 200 Massachusetts Avenue, NW, Suite 1100, Washington, DC 20001, standards@api.org.

Contents

Page

1. Scope 1

   1. Purpose 1

   2. Applicability 1

2. Normative References 1

3. Terms, Definitions, Acronyms, and Abbreviations 1

   3.2 Acronyms and Abbreviations 3

4. Heat Treatment Supplier Qualification 3

   1. Establishment of the Process Being Qualified 3

   2. Quality Management System (QMS) 3

5. Responsibilities and Duties 4

   1. General 4

   2. Personnel Training Requirements 4

6. Identification and Traceability 4

7. Calibration 4

   1. Equipment Calibration 4

   2. Temperature Uniformity Survey (TUS) 5

8. Process Control 12

   1. Instruments 12

   2. System Accuracy Tests (SATs) 12

   3. Heat Treatment Quench Requirements 13

   4. Movement of Product 14

9. Heat Treatment Procedures 14

   1. General 14

   2. Furnace Atmosphere 14

   3. Process Validation 15

   4. Heat Treatment Equipment Maintenance 15

10. Manufacturing Process Specification 15

    1. General 15

    2. Heat Treatment Parameters 15

    3. Quench Parameters 16

    4. Test Requirements 16

11. Heat Treatment Records 16

    1. General 16

    2. Document Control 16

    3. Records to be Maintained by Heat Treatment Supplier 16

    4. Minimum Requirements for Heat Treatment Certificates 16

12. Record Retention 17

13. Handling, Storage, and Shipping 18

    Contents

    Page

14. Minimum Facility Requirements 18

Bibliography 19

Figures

1. Thermocouple Locations—Rectangular Furnace (Working Zone) 10

2. Thermocouple Locations—Cylindrical Furnace (Working Zone) 11

Tables

1. Number of TUS Sensors for the Volumetric Method 5

2. Classification of Instrument Types 6

3. Raw Material—Instrument Type and TUS Survey Intervals 6

4. Permitted Calibration/Test Interval Extension 6

5. Raw Material—Instrument Type and System Accuracy Tests (SAT) Interval 13

6. Minimum Facility Requirements 18

Heat Treatment Services—Continuous Line for Equipment Used in the Petroleum and Natural Gas Industry

1. Scope

   
   

   1. Purpose

      
      

      This standard specifies requirements for the qualification of suppliers of continuous line heat treatment services

      used in the manufacture of equipment for the petroleum and natural gas industries.

      
      

   2. Applicability

      
      

      This standard is applicable to suppliers providing heat treatment services where API product standards specify this standard as a requirement for conformance. The requirements of this standard apply to continuous and semi-continuous heat treatment operations that can establish or affect the final mechanical properties. For batch type heat treatment refer to API 20H. This standard is applicable to products in tubular, bar, plate, forgings, castings and upset forged forms. Heat treat that imparts surface hardening or case hardening is outside the scope of this document.

      
      

      NOTE This standard does not limit the responsibility of any manufacturer of commercial products using continuous line heat treatment services and manufactured to an API standard from its responsibility for compliance with all applicable requirements of that API standard.

      
      

2. Normative References

The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any addenda) applies.

API Specification Q1, Specification for Quality Management System Requirements for Manufacturing Organizations for the Petroleum and Natural Gas Industry

ISO 9001, Quality management systems—Requirements

3 Terms, Definitions, Acronyms, and Abbreviations

3.1 For purposes of this standard, the following terms, definitions, acronyms, and abbreviations apply.

3.1.1

acceptance criteria

Defined limits placed on characteristics of materials, processes, products or services.

3.1.2

continuous furnace

Heating device through which material is moved intentionally at a constant rate during the processing cycle.

3.1.3

cycle time

Time within the furnace for austenitizing or tempering.

3.1.4

final inspection

The final visual examination, and documentation release of the heat-treated material.