Welding Guidelines for the Chemical, Oil, and Gas Industries

API RECOMMENDED PRACTICE 582 THIRD EDITION, MAY 2016

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Foreword

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1. Scope 1

2. Normative References 1

3. Definitions 3

4. General Welding Requirements 3

5. Welding Processes 4

   1. Acceptable Welding Processes 4

   2. Limitations of Fusion Welding Processes 4

   3. Single-sided Welded Joints 7

   4. Combining Welding Processes 7

   5. Mechanized and Automated Welding Processes 7

6. Welding Consumables (Filler Metal and Flux) 7

   1. General 7

   2. Dissimilar Welding 8

   3. Low-alloy Steel Welding (P-No. 3 to P-No. 5 and P-No. 15E) 9

   4. Stainless Steel Welding (P-No. 6, P-No. 7, and P-No. 8) 9

   5. Duplex and Super Duplex Stainless Steel Welding 10

   6. SAW 11

   7. Electroslag Welding (for Corrosion Resistant Weld Overlay) 11

   8. Consumable Storage and Handling 11

   9. Alloy Consumable Controls 11

7. Shielding and Purging Gases 11

8. Preheating and Interpass Temperature 12

9. Post-weld Heat Treatment (PWHT) 12

10. Cleaning and Surface Preparation 16

11. Special Procedure Qualification Requirements/Testing 16

    1. General 16

    2. Tube-to-tubesheet Welding 17

    3. Additional Procedure Qualification Requirements for Duplex and Super Duplex Stainless Steels 17

12. Other Items 19

    1. Backing Materials 19

    2. Peening 19

    3. Weld Overlay and Clad Restoration (Back Cladding) 19

    4. Temporary Attachments 20

    5. Stud Welding 20

    6. Hardness Testing—Weld Procedure Qualification and Production Testing 20

    7. Single-pass Welds 20

    8. Additional Production Requirements for Welding Duplex and Super Duplex Stainless Steel 20

Annex A (informative) Welding Consumables for Shielded Metal Arc Welding (SMAW) 22

Annex B (normative) Weld Overlay and Clad Restoration (Back Cladding) 27

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Tables

1. Diffusible Hydrogen Limits for FCAW Consumables 6

2. Application of Nickel-base Electrodes in Sulfidation and Non-sulfidation Environments 9

3. Additional Chemical Requirements for Duplex and Super Duplex Stainless Steel Consumables and As-welded Deposits 10

4. Recommended Maximum Interpass Temperatures 13

5. Maximum Recommended Interpass Temperatures for Duplex and Super Duplex Stainless Steels 13

6. PWHT Temperatures and Holding Times 14

1. Carbon and Low-alloy Steel 23

2. Stainless Steel Alloys 24

3. Duplex Stainless Steels 25

4. Copper-nickel and Nickel-base Alloys 26

1. Filler Material Selection for Overlay of Carbon and Low-alloy Steels 28

2. Chemical Composition Requirements for Austenitic Stainless Steel Overlays 29

Welding Guidelines for the Chemical, Oil, and Gas Industries

1. Scope

   1. This recommended practice (RP) provides supplementary guidelines and practices for welding and welding related topics for shop and field fabrication, repair and modification of the following:

      
      

      1. pressure-containing equipment such as pressure vessels, heat exchangers, piping, heater tubes, and pressure boundaries of rotating equipment and attachments welded thereto;

         
         

      2. tanks and attachments welded thereto;

         
         

      3. non-removable internals for process equipment;

         
         

      4. structural items attached and related to process equipment;

         
         

      5. other equipment or component items when referenced by an applicable purchase document.

      
      

   2. This document is general in nature and augments the welding requirements of ASME BPVC Section IX and similar codes, standards, specifications, and practices such as those listed in Section 2. The intent of this document is to be inclusive of chemical, oil and gas industry standards, although there are many areas not covered herein, e.g. pipeline welding and offshore structural welding are intentionally not covered.

      
      

   3. This document is based on industry experience and any restrictions or limitations may be waived or augmented by the purchaser.

      
      

2. Normative References

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. Other codes and standards are specified by the purchaser.

API 510, Pressure Vessel Inspection Code: Maintenance, Inspection, Rating, Repair, and Alteration

API Recommended Practice 934-A, Materials and Fabrication of 2 1/4Cr-1Mo, 2 1/4Cr-1Mo-1/4V, 3Cr-1Mo, and 3Cr-1Mo-1/4V Steel Heavy Wall Pressure Vessels for High-temperature, High-pressure Hydrogen Service

API Recommended Practice 934-C, Materials and Fabrication of 1 1/4Cr-1/2Mo Steel Heavy Wall Pressure Vessels for High-pressure Hydrogen Service Operating at or Below 825 °F (441 °C)

API Recommended Practice 934-E, Recommended Practice for Materials and Fabrication of 1 1/4Cr-1/2Mo Steel Pressure Vessels for Service Above 825 °F (440 °C)

ASME Boiler and Pressure Vessel Code (BPVC) 1, Section I, Rules for Construction of Power Boilers

ASME Boiler and Pressure Vessel Code (BPVC) Section II, Part C: Specifications for Welding Rods, Electrodes, and Filler Metals

ASME BPVC, Section VIII: Rules for Construction of Pressure Vessels

ASME BPVC, Section IX: Welding and Brazing Qualifications

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

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