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