Manufacture of Structural Steel Castings for Primary Offshore Applications

API SPECIFICATION 2SC

FIRST EDITION, SEPTEMBER 2009 EFFECTIVE DATE: MARCH 1, 2010

REAFFIRMED, SEPTEMBER 2020

Manufacture of Structural Steel Castings for Primary Offshore Applications

Upstream Segment

API SPECIFICATION 2SC

FIRST EDITION, SEPTEMBER 2009 EFFECTIVE DATE: MARCH 1, 2010

REAFFIRMED, SEPTEMBER 2020

Special Notes

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Copyright © 2009 American Petroleum Institute

Foreword

This specification is based on the experience acquired during the design, construction, operation and maintenance of offshore processing units and permanent facilities, as supplemented with the experience of operating companies with topsides, fixed platforms, floating structures (e.g. TLPs, spars, and the like), and their tendons and risers. Castings in these applications tend to be limited production components, with relatively few replications, and receive more intense scrutiny than routine mass production runs.

Where appropriate, this specification is based on, or reference is made to, international, regional, national and industry standards.

This is a manufacturing specification for the casting itself. It is anticipated that geometric design for both service requirements and casting feasibility will have been agreed collectively between the contractor, manufacturer, and purchaser before this specification is invoked. Attendant issues regarding system reliability, geometric design, incorporation into the overall construction, operation, and maintenance are not addressed here. Those electing to use this specification as a reference for their needed level of performance quality should carefully consider all these attendant issues.

When contractors or manufacturers/suppliers use this specification they should be solely responsible for the quality of work and the attainment of the required design and engineering standards. In particular, for those requirements not specifically covered, the purchaser will expect them to follow those design and engineering practices which will achieve the same level of integrity as reflected in their best production. If in doubt, the contractor or manufacturer/ supplier should, without detracting from his own responsibility, consult the purchaser or its technical advisor.

The purchaser may then negotiate with the authorities concerned with the object of obtaining agreement to follow this specification as closely as possible.

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.

This document was produced under API standardization procedures that ensure appropriate notification and participation 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.

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Contents

Page

1. Scope 1

2. Normative References 1

3. Terms, Definitions, and Acronyms 2

   1. Term and Definitions 2

   2. Acronyms 3

4. Quality Requirements, Quality Plan (QP), and Manufacturing Procedure Specification (MPS) 4

   1. General 4

   2. Procurement Specification 4

   3. Lowest Anticipated Service Temperature (LAST) 4

   4. Service Categories 4

   5. Critical Sections. 5

   6. Underlying Industry Standard Specification 5

   7. Traceability 5

   8. Information to be Supplied to the Casting Manufacturer 5

   9. Document Requiring Approval by the Purchaser and Contractor 6

   10. Preproduction Meeting 7

   11. Post-job Production Histograms 7

   12. Certificates 7

5. Process of Manufacture and Chemical Composition 7

   1. General 7

   2. Chemical Composition 7

6. Heat Treatment 9

   1. Heat Treatment Process Control Requirements 9

   2. Quenching 9

   3. Heat-treatment Furnace Records or Charts, Temperatures and Cycle Times 9

7. Qualification Test Sample (QTS) 9

   1. Castings Represented by QTS 9

   2. QTS Dimensional Requirements 10

   3. QTS Heat Treatment 10

   4. Partial Severing of Quality Test Samples 10

8. Mechanical Properties and Tests 11

   1. Tensile Tests 11

   2. Hardness Tests 11

   3. Charpy V-notch Impact Tests (CVN Tests) 12

   4. Drop-weight or Pellini Test (DWT) 12

9. Repair Welding of Castings 13

   1. Approval of Repair Welding WPSs and PQRs and Code Compliance 13

   2. Allowable Welding Processes 13

   3. PWHT of Major Weld Repairs 13

   4. Identification 14

   5. Records of Welder and Welding Operator Qualification Test Results 14

   6. Welding Consumables 14

   7. Welding Procedure Specification (WPS) 15

   8. Repair Weld Procedure Qualification Requirements 16

   9. Repair Weld Workmanship and Technique 19

      Page

   10. NDT of Repair Welds Made During Production 20

   11. Repair Weld Charts and Maximum Allowable Repair Weld Volume and Surface Area 21

10. NDT of Castings 21

    1. General 21

    2. VT of Castings 21

    3. NDT of Castings for Surface Defects 22

    4. NDT of Castings for Subsurface Indications 23

    5. Documentation of NDT results 24

11. Dimensional Inspection 24

12. MTR 25

Annex A (informative) Use of the API Monogram by Licensees 26

Bibliography 29

Tables

1. Document Submittals Requiring Approval by the Purchase 6

2. Elemental Limits 8

3. Tensile Properties and Hardness Requirements 11

4. CVN Absorbed Energy Requirements—SCA and SCB 13

5. CVN Absorbed Energy Requirements—SCC 13

6. Test Locations for CVN Specimens 18

Introduction

This specification defines the minimum requirements for manufacture, testing, and inspection of carbon and low-alloy steel castings Grades 345 to 586 N/mm2 (50 ksi to 85 ksi) for use in primary steel applications in the fabrication of offshore structures, manufacture of marine mechanical, or riser, tendon, or other equipment intended for application on permanent offshore structures, or for components thereof.

Service categories (A, B, and C), as defined in 4.4, reflect casting geometry and method of incorporation into the overall system. They may also be designated by the user (purchaser) to reflect moderately different but standardized levels of performance.

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Manufacture of Structural Steel Castings for Primary Offshore Applications

1. Scope

   Castings manufactured to this specification are intended for use in the fabrication of offshore structures, manufacture of critical marine or mechanical or other system components intended for application on permanent offshore structures, or for components used in the construction of offshore tendons, risers and pipelines.

   
   

   If national and/or local regulations exist in which some of the requirements may be more stringent than in this specification the contractor shall determine which of the requirements are more stringent and which combination of requirements will be acceptable with respect to safety, environmental, economic, and legal aspects. In all cases, the contractor shall inform the purchaser of any deviation from the requirements of this specification which is considered to be necessary in order to comply with national and/or local regulations.

   
   

2. Normative References

The following referenced documents are indispensable in the application of this standard. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

ASME Boiler and Pressure Vessel Code (BPVC) 1, Section V: Nondestructive Examination; Section VIII: Pressure Vessels; Section IX: Welding and Brazing Qualifications

ASNT SNT-TC-1A 2, Recommended Practice, Personnel Qualification and Certification in Nondestructive Testing

ASTM A609:1991 3, Standard Practice for Castings, Carbon, Low-Alloy, and Martensitic Stainless Steel, Ultrasonic Examination Thereof

ASTM A703:2008, Standard Specification for Steel Castings, General Requirements, for Pressure-Containing Parts

ASTM E10, Standard Test Method for Brinell Hardness of Metallic Materials

ASTM E23, Standard Test Methods for Notched Bar Impact Testing of Metallic Materials

ASTM E92, Standard Test Method for Vickers Hardness of Metallic Materials

ASTM E110, Standard Test Method for Indentation Hardness of Metallic Materials by Portable Hardness Testers

AWS A4.3 4, Standard Methods for Determination of the Diffusible Hydrogen Content of Martensitic, Bainitic, and Ferritic Steel Weld Metal Produced by Arc Welding

AWS A5.01, Filler Metal Procurement Guidelines

AWS D1.1:2008, Structural Welding Code—Steel

BSI BS 2M 54 5, Specification for Temperature Control in the Heat Treatment of Metals

1. ASME International, 3 Park Avenue, New York, New York 10016-5990, www.asme.org.

2. American Society for Nondestructive Testing, 1711 Arlingate Lane, P.O. Box 28518, Columbus, Ohio 43228, www.asnt.org.

3. ASTM International, 100 Barr Harbor Drive, West Conshohocken, Pennsylvania 19428, www.astm.org.

4. American Welding Society, 550 NW LeJeune Road, Miami, Florida 33126, www.aws.org.

5. British Standards Institution, Chiswick High Road, London, W4 4AL, United Kingdom, www.bsi-global.com.

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