Glossary (and Abbreviations)

(and Abbreviations)

The glossary below has two tabs:
Terminology & Organizations for HT Quality.

Click the tab you wish to view.

Terminology (In A ~ Z Order):

A ~ H

  • FCP: Flexible Ceramic Pad. This is the heater used in electrical resistance HT.
  • GCB: Gradient Control Band. This is the widest band and covers all area under insulation.
  • HAZ: Heat Affected Zone. It refers to the parts of the base metal that is around a weld and has been affected by the heat from welding activities.
  • HB: Heated Band. This band receives most of its heat from the SB, and its size is in-between that of GCB and SB.
  • HT: Heat treatment. This is the engineering process used to prepare materials for welding, transformation, etc.
  • Hydrogen Bakeout: This HT process is used to remove harmful substances from the workpiece, such as hydrogen, moisture, etc. In other words, it removes more than just hydrogen.

I ~ P

  • LNG: Liquid natural gas. Examples are: methane, ethane, etc. This industry uses a lot of HT, welding, etc.
  • Lower Critical Temperature: This refers to the temperature HT must avoid reaching or exceeding because it may change a material’s attributes and molecular structure. Different materials can have different lower critical temperatures.
  • OD: Outer Diameter. This term is usually used to describe a pipe’s size, and it refers to a pipe’s diameter that includes the thickness of the pipe wall.
  • Post-Heating: This HT process may not be present in all HT projects and is often used to transition the HT process in-between shifts.
  • PPE: Personal protective equipment. Example are gloves, face-shield, etc.
  • Pre-Heat: This HT process begins before the welding starts and continues through the welding process.
  • PWHT: Post-Weld Heat Treatment. This HT process takes place after the welding is done.

Q ~ Z

  • SB: Soak Band. This band is the narrowest, hottest band situated at the heart of the GCB and SB.
  • T/C: Thermocouple. This is the temperature monitor and control device attached to the workpiece.
  • Welding Tacks: It refers to the small welds (also called spot welds) that hold things in place before the welding begins.


  • API: American Petroleum Institute
  • ASME: American Society of Mechanical Engineers
  • AWS: American Welding Society
  • NBIC: National Boiler Inspection Code
  • WRC: Welding Regulatory Council


We have a page that lists some of the most commonly-used codes from these organizations. To see the codes, click HERE.


OrganizationCode Namecode DescriptionsDownload
ASMEASME B31.3-2016Process Piping. ASME Code for Pressure Piping, B31Free Download
ASMEASME B31P-2017Standard Heat Treatments for Fabrication Processes, ASME Code for Pressure Piping, B31Free Download
ASMEASME Sec 1 – 2019ASME Boiler and Pressure Vessel Code. An International Code. Rules for Construction of Power Boilers.Free Download
ASMEASME VIII Div 1-2013Rules for Construction of Pressure Vessels, Division 1Free Download
AWSAWS D10.10Recommended Practices for Local Heating of Welds in Piping and TubingFree Download
AWSAWS D10.22Specification for Local Heating of Welds in Creep Strength-Enhanced Ferritic Steels in Piping and Tubing Using Electronic Resistance HeatingPurchase Here
BPVCASME BPVC.I-2019Non Mandatory Appendix C.Free Download
WRCWRC bulletin 452Recommended Practices for Local Heating of Welds in Pressure VesselsFree Download

Quality means doing it right–when no one is looking.

Henry Ford

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