Considerations for oil and gas welding

15 September 2020

Welding is used widely across the oil and gas industry to join different components and assemblies together. Pipelines, tanks, and valves are just some of the assets that require welding to create a system for extracting, refining and delivering petroleum-based goods. There are several aspects of designing and making welds in this industry that need to be considered to help ensure successful and safe welding procedures are created and carried out. 

Materials

The risk of corrosion brings up a consideration when welding in the oil and gas industry, and that is the materials that are used. This applies to both base metals and filler metals. To prevent corrosion and have mechanical properties appropriate for the application, oil and gas projects often involve several different types of materials.

The different metals used in an oil and gas project oftentimes behave quite differently from one another when welding. Examples of these different metals include carbon steel, low alloy steel, duplex stainless steel, austenitic stainless steel, nickel-based alloys such as Inconel, and titanium. Puddle fluidity, melting temperature, thermal expansion and thermal conductivity can all vary greatly. Because of this, a welder who is skilled at welding one metal may not be the right person to weld another.

Welder skill

Welding in the oil and gas industry often means welding round or irregularly shaped parts together. Examples of each include pipes and large tanks, respectively. This can make welding difficult for several reasons.

Many times out-of-position welding is required. When welding out of position, a welder or welding operator needs to know how to manipulate the weld pool under different gravitational forces than what is considered normal in the flat position. This can be quite difficult to master.

Another reason that irregularly shaped or round parts make welding more difficult is the constant and sometimes difficult movements required to maintain a proper work angle, travel angle, travel speed and electrode to work distance during the welding process. This too oftentimes can only be done by experienced welders and welding operators. 

Courtesy of the American Welding Society.