Table of Contents

Personnel(Reaffirmation)
Personnel(Original)
Foreword
List of Tables
List of Figures
1. Scope
2. Reference Documents
    2.1 Piping Fabrication Codes
    2.2 Repair Codes
    2.3 Recommended Practices Regarding Service
          Environment
3. Introduction
4. Purposes for Local Heating
    4.1 Bake-Out
    4.2 Preheating and Interpass Heating
    4.3 Postheating
    4.4 Postweld Heat Treatment (PWHT)
5. Terminology for Local Heating
    5.1 Soak Band (SB)
    5.2 Heated Band (HB)
    5.3 Gradient Control Band (GCB)
    5.4 Control Zone
6. Local 360-Degree Band Heating
    6.1 Soak Band
    6.2 Heated Band
    6.3 Gradient Control Band
    6.4 Axial Temperature Gradient
    6.5 Summary of Recommendations for SB, HB, GCB, and
          Axial Temperature Gradient
    6.6 Recommended PWHT Practices
7. Local Spot PWHT
    7.1 Requirements in Fabrication and Repair Codes
    7.2 Basis for Current Practices
    7.3 Experience or Analysis to Justify Use
8. Measurement of Temperature
    8.1 Temperature-Indicating Crayons and Paints
    8.2 Selection of Thermocouples
    8.3 Installation of Thermocouples
    8.4 Location of Thermocouples
    8.5 Thermocouple Extension Wires
    8.6 Temperature Control and Recording Instruments
    8.7 Accuracy of Thermocouple Temperature Measurements
9. Insulation
    9.1 Classification of Insulation
    9.2 Health and Safety Issues Regarding Fiber Respirability
    9.3 Types of Insulation
    9.4 Attachment of Insulation
10. Other Considerations
    10.1 Structural Integrity
    10.2 Internal Liquids
    10.3 Internal Convection
    10.4 Thermal Expansion
11. Thermal Cycle
    11.1 Temperature Uniformity
    11.2 Heating Rate
    11.3 Hold Temperature and Time
    11.4 Cooling Rate
12. Response to Deviations
    12.1 Thermocouple Failure
    12.2 Heat Source Failure
    12.3 Interruption During Heating
    12.4 Interruption During Hold Period
    12.5 Interruption During Cooling
    12.6 Excessive Heating or Hold Times During PWHT
13. Considerations Related to Service Environment
    13.1 Appropriateness of Furnace and Local PWHT
    13.2 Exemption from PWHT
    13.3 Tempering and Stress Relaxation Objectives
    13.4 Hardness Testing
    13.5 Induction Heating Stress Improvement (IHSI)
14. Quality Assurance System
    14.1 Quality System
    14.2 Process Control
    14.3 Response to In-Process Deviations
    14.4 Testing
    14.5 Documentation
    14.6 Control of Inspection, Measuring, and Test Equipment
    14.7 Training
    14.8 Servicing
15. Induction Heating
    15.1 General
    15.2 Effect of Composition and Temperature
    15.3 Coil
    15.4 Ampere Turns
    15.5 Location of Turns of the Coil
    15.6 Suggestions for Setup
    15.7 Relative Advantages and Disadvantages of Induction
          Heating
16. Electric Resistance Heating
    16.1 General
    16.2 Heaters
    16.3 Power Sources
    16.4 Suggestions for Setup
    16.5 Relative Advantages and Disadvantages of Resistance
          Heating
17. Flame Heating
    17.1 General
    17.2 Heat Sources
    17.3 Torch Tip Sizes
    17.4 Heated Band
    17.5 Flame Adjustment
    17.6 Flame Attitude
    17.7 Protection from the Elements
    17.8 Holding
    17.9 Cooling
    17.10 Suggestions for Setup
    17.11 Relative Advantages and Disadvantages of Flame Heating
18. Exothermic Heating
    18.1 General
    18.2 Nature of the Process
    18.3 Determination of Process Suitability
    18.4 Suggestions for Setup
    18.5 Relative Advantages and Disadvantages of Exothermic
          Heating
19. Gas-Flame Generated Infrared Heating
    19.1 General
    19.2 Fundamentals
    19.3 Burner Arrangement
    19.4 Process Control
    19.5 Sheltering of Thermocouples
    19.6 Suggestions for Setup
    19.7 Relative Advantages and Disadvantages of Gas-Flame
          Generated Infrared Heating
20. Radiant Heating by Quartz Lamps
    20.1 General
    20.2 Description of the Heating Method
    20.3 Heater
    20.4 Thermal Cycle Control
    20.5 Effect of Work Surface Condition
    20.6 Suggestions for Setup
    20.7 Relative Advantages and Disadvantages of Quartz Lamp
          Radiant Heating
21. Comparison of Heating Processes
22. Safety and Health
    22.1 Noise
    22.2 Electrical Hazards
    22.3 Fire and Explosion Protection
    22.4 Burn Protection
    22.5 Tripping and Falling
    22.6 Falling Objects
    22.7 Confined Spaces
    22.8 Electric and Magnetic Fields (EMF)
    22.9 Lockout/Tagout
Annex A (Informative) - Discussion of Issues and Recommendations
         Regarding the Heated Band
Annex B (Informative) - Discussion of Stresses Induced During Local
         360-Degree Band PWHT
Annex C (Informative) - Procedure for Thermocouple Attachment
         by Capacitor Discharge Welding
Annex D (Informative) - Accuracy of Thermocouple Temperature
         Measurements
Annex E (Informative) - Information on Types of Insulation
Annex F (Informative) - Standard Procedure for Local Heating
Annex G (Informative) - Standard Documentation Checklist for
         Local Heating
Annex H (Informative) - Guidelines for the Preparation of
         Technical Inquiries
List of AWS Documents on Piping and Tubing

Abstract

Explains several methods of applying controlled heat to weld joints and a limited volume of base metal adjacent to the joints, as opposed to heating the complete weldment in a furnace or oven.

General Product Information

Published
Document Type	Standard
Status	Current
Publisher	American Welding Society
ProductNote	Reconfirmed 2009
Pages
ISBN
Committee	D10