Category: WELDING

WELDING, Welding Engineer1 Comment

ASME IX QW-402.4 variable

Amarine Antonio

QW-402.4 The deletion of the backing in single welded groove welds. Double‐welded groove welds are considered welding with backing. Note: From 1980 to 2019, this variable underwent many revisions, to fully understand backing, we need to review the definition of backing in definitions section. Backing: a “material” placed at the root of a weld joint for the purpose of supporting molten weld metal so as to facilitate complete joint penetration. The material may or may not fuse (retainer) into the joint. Backing gas: a gas, such as argon, helium, nitrogen, or reactive gas, which is employed to exclude oxygen from … Continue reading ASME IX QW-402.4 variable

WELDING, Welding Engineer1 Comment

ASME IX QW-402.1 variable

Amarine Antonio

QW-402.1 A change in the type of groove (Vee‐groove, U‐groove, single‐bevel, double‐bevel, etc.). Note: QW-402.1 is frequently addressed by adding a separate drawing of the allowable joint designs permitted by WPS, the actual joint is specified on Fabrication drawing and it should be one of the permitted joint types. In many cases, it is acceptable to permit or specify “Groove and Fillet”, “V-Groove”, “Socket weld and grooves”, ect., in order to satisfy this nonessential variable. Normally, all most nonessential variables leave a lot of judgments up to the manufactures when writing WPS. In some fabrication situations a change in groove … Continue reading ASME IX QW-402.1 variable

WELDING, Welding Engineer2 Comments

ASME IX: WPS variables – Joint design

Amarine Antonio

QW-402.1 A change in the type of groove (Vee‐groove, U‐groove, single‐bevel, double‐bevel, etc.). Please see the interpretation: ASME IX QW-402.1 variable QW-402.4 The deletion of the backing in single welded groove welds. Double‐welded groove welds are considered welding with backing. Please see the interpretation: ASME IX QW-402.4 variable QW-402.5 The addition of a backing or a change in its nominal composition. It is used when the EB insert – fusible backing, incorporated with weldment in GTAW. QW-402.10 A change in the specified root spacing. Please see the interpretation: ASME IX QW-402.10 variable QW-402.11 The addition or deletion of nonmetallic retainers or non-fusing metal … Continue reading ASME IX: WPS variables – Joint design

WELDING, Welding Engineer5 Comments

Back gouging in welding

Amarine Antonio

When welding on thick plate or pipe, it is often impossible for the welder to get 100% penetration without some type of groove being used. The groove may be cut into just one of the plates or pipes or both. On some plates it can be cut both inside and outside of the joint. The groove may be ground, flame cut, gouged, sawed, or machined on the edge of the plate before or after the assembly. Bevels and V-grooves are best if they are cut before the parts are assembled. J-grooves and U-grooves can be cut either before or after assembly. … Continue reading Back gouging in welding

WELDING, Welding Engineer6 Comments

In-situ Buttering welding

Amarine Antonio

In-situ Buttering is deposition of a layer of weld metal on the susceptible surface (‘buttering’) prior to filling the joint ensures that strains due to the weld passes in contact with the steel are low. Or it is special buttering type different from the others – See Buttering vs Buildup in welding The deposition of low strength weld metal is deposited firstly on the susceptible plate before filling the joint with another electrode. However, before adopting this technique, design calculations should be carried out to ensure that the overall weld strength would be acceptable. Notes: Some O&G project has allowed using … Continue reading In-situ Buttering welding

WELDING, Welding Engineer7 Comments

Buttering vs Buildup in welding

Amarine Antonio

The buildup is a surfacing variation in which surfacing material is deposited to achieve required dimensions. The term buildup denotes the addition of weld metal to a base metal surface, the edge of a joint, or previously deposited weld metal for the restoration of the component to the required dimensions. In this case, the strength of the weld metal is a necessary consideration in the component design. The Buttering is a surfacing variation used to deposit surfacing metal on one or more surfaces to provide compatible weld metal for the subsequent completion of the weld. Buttering differs from buildup in that … Continue reading Buttering vs Buildup in welding

WELDING, Welding Engineer3 Comments

Backing vs Retainer in Welding

Amarine Antonio

The backing is defined as material placed at the root of a weld joint for the purpose of supporting molten weld metal. Its function is to facilitate complete joint penetration. Permanent backing is usually made from a base metal similar to that being welded and, as the name implies, becomes a permanent part of the joint because it is fused to the root of the weld and is not easy to remove — See: Backing in welding for more information. Temporary backing may be made from copper or a ceramic substance that do not become fused to the root and are easily … Continue reading Backing vs Retainer in Welding

WELDING, Welding Engineer7 Comments

Backing in welding

Amarine Antonio

A backing (strip) is a piece of metal that is placed on the backside of a weld joint to prevent the molten metal from dripping through the open root (burn through). It helps to ensure that 100% of the base metal’s thickness is fused by the weld (full penetration). The backing may be either left on the finished (cofferdam or void space closing welds without both-sides accessibility) weld or removed following welding (Ceramic backing, Copper strips). If the backing is to be removed, the letter R is placed in the backing symbol.  The backing is often removed from a finished weld … Continue reading Backing in welding

WELDING, Welding Engineer4 Comments

Groove Design & Bevel Preparation

Amarine Antonio

Weld preparation  Preparation for making a connection where the individual components, suitably prepared and assembled, are joined by welding or brazing. The dimensions below can vary depending on WPS. Angle of bevel The angle at which the edge of a component is prepared for making a weld. For an MMA weld on carbon steel plates, the typical angles is: 25-30 Deg.  for a V preparation. 8-12 Deg. for a U preparation. 40-50 Deg. for a single bevel preparation. 10-20 Deg. for a J preparation Note: The value is only for reference, the angle and groove type is depending on structure design type, welding processes, and … Continue reading Groove Design & Bevel Preparation