Category Archives for Fabrication
Consumables – Flux
Flux is used in several different forms depending upon the welding process. For the SMAW process, it is extruded as a coating on the electrodes. For the FCAW process, it is added as a powder inside the cored electrode. For … Continue reading
Submerged Arc Welding
The SAW (submerged arc welding) process uses a continuously fed consumable electrode (or electrodes) in the form of a wire or strip (for weld overlays) from a coil and a granular flux. The process is similar to GMAW except that … Continue reading
Flux Cored Arc Welding
FCAW (flux cored arc welding) is a variation of the GMAW process which uses flux-cored wire instead of solid bare wire. Among other things, the flux forms a slag which helps hold the molten metal in place so the process … Continue reading
Gas Metal Arc Welding
GMAW (gas metal arc welding), commonly referred to as “MIG” welding, utilizes an automatically fed consumable electrode in the form of wire from a spool for the filler metal. Inert shielding gas is supplied through an annular nozzle at the … Continue reading
Gas Tungsten Arc Welding
GTAW (gas tungsten arc welding), commonly referred to as “TIG” welding, utilizes a nonconsumable tungsten electrode and separate filler metal in the form of wire (separate filler metal is not always used for very thin sections). Inert shielding gas is … Continue reading
Shielded Metal Arc Welding
SMAW (shielded metal arc welding), commonly referred to as “stick” welding, is strictly a manual process that uses a consumable flux-coated metal electrode to provide filler metal, flux, and slag. (See Figures 600-8 and 600-9.) The SMAW process is the … Continue reading
Postweld Heat Treatment
Note PWHT is a very important factor that can have a significant effect on the integrity and reliability of the vessel. Omitted or improperly performed postweld heat treatments can lead to failure of the vessel. The pressure vessel specifications recommend … Continue reading
Skirt Attachment Weld
Attaching a support skirt to a pressure vessel does not involve a pressure containing weld. Nevertheless, the skirt attachment weld must be made properly to provide the integrity required to reliably support the vessel, including the maximum wind and earthquake … Continue reading
Girth NDE
ASME Code, Section VIII, Division 1, has recently changed the requirements for NDE to permit spot RT of girth welds (Category B welds) when full RT is required for longitudinal welds (Category A welds) for design with a joint efficiency … Continue reading
Girth Welds
The cylindrical shell and head components are joined together with girth welds (Category B welds). These welds are usually made using a welding procedure employing a combination of automatic SAW and manual SMAW that is very similar to those described … Continue reading