Welding Codes and Standards Ch 22

Chapter 22: Welding Codes and Standards

Objectives

  • Differentiate between qualification and certification.

  • List major considerations for selecting a code or standard.

  • Write a welding procedure and specification.

  • Identify the three most common codes and describe their major uses.

  • Outline steps to certify a weld and welder.

  • Explain how a tentative WPS becomes a certified WPS.

Key Terms

  • API Standard 1104: Code for welding pipelines.

  • ASME Section IX: Code for pressure vessels and nuclear components.

  • AWS D1.1: Code for structural steel welding (bridges, buildings).

  • Code: A detailed set of rules governing welding procedures.

  • Procedure Qualification Record (PQR): Document recording the welding procedure and results.

  • Specification: A detailed statement of legal requirements for welding.

  • Standard: Agreed approaches to welding processes.

  • Welding Procedure Specification (WPS): A document outlining how to conduct welding.

  • Welding Schedule: Federal/military specification denoting a WPS.

Introduction

  • Consistent quality and safety in welding achieved through codes and standards.

  • Agencies establish frameworks so skilled welders ensure uniform quality in welds.

  • Proper testing procedures certify welder skills for reliable welds.

  • Code selection impacts cost and product safety; incorrect choices can lead to excess costs or safety failures.

Codes, Standards, Procedures, and Specifications

  • Purpose: Codes and specifications provide guidelines for specific welding applications, requiring qualifications by testing.

  • Welding Code: A comprehensive set of rules for a specific type of product.

  • Welding Specification: Details legal requirements for a specific weld type, requiring inspections and tests.

Factors for Selecting Codes/Standards

  • Compliance with local, state, or federal regulations.

  • Requirements from bonding or insurance companies for safety.

  • Customer (end-user) expectations regarding cost and reliability.

  • Adherence to standard industrial practices known within the industry.

Commonly Used Codes

  • API Standard 1104: Primarily for pipelines, established by the American Petroleum Institute.

  • ASME Section IX: Pertains to pressure vessels and nuclear components by the American Society of Mechanical Engineers.

  • AWS D1.1: Related to bridges, buildings, and structural steel by the American Welding Society.

Welding Procedure Qualification

Welding Procedure Specification (WPS)

  • A WPS outlines instructions for achieving sound welds.

  • Must comply with relevant codes and specifications; includes details like welding process, technique, settings for amperage, voltage, and preheating.

  • Essential parameters must be documented clearly for reproducibility by qualified welders.

Qualifying a Welding Procedure

  • Qualification shows that the variables in the WPS will result in a sound weld.

  • Sample welds produced per WPS tested under supervision.

  • Procedure Qualification Records (PQR) document the specifics of the process and results.

Steps for Qualification and Certification

  1. Prepare a tentative welding procedure by knowledgeable personnel.

  2. Conduct test welds using the tentative WPS and document parameters on the PQR.

  3. Test samples under supervision by authorized personnel.

  4. If tests pass, finalize the WPS for production use.

  5. If tests fail, adjust the WPS and retest until passing.

  6. The welder of the test samples is considered qualified upon successful tests.

  7. Additional welders must pass tests according to the clarified WPS to become certified.

  8. Qualified WPS can remain effective until a more efficient process supersedes it.

  9. welder’s qualification generally lasts until a six-month inactivity period necessitates requalification.

Important Considerations

  • The outline format of WPS varies but must include all parameters listed by the applicable standards.

  • Essential variables directly affect the mechanical properties and must be requalified if changed.

  • Nonessential variables allow for some flexibility without requiring complete requalification.

  • Differences exist in code requirements for groove weld positions and testing methodologies.

Practice Exercises

  • Practice 22-1: Write a Welding Procedure Specification using provided formats.

  • Practice 22-2: Complete a Procedure Qualification Record after welding based on the WPS.