“You should give as much consideration to the preparation as you do to the actual welding”
Pipe welding is utilized all around the world in diverse industries. A variety of pipe sizes and material grades are joined to manufacture components of various shapes and lengths – from a few feet to many miles. Even though most pipe welding jobs have custom specifications – there are some fundamental aspects of pipe welding that form a common thread for welders and welding engineers alike in order to achieve high quality welds in pipes.
Selecting The Right Pipe Welding Equipment
Equipment selection is the top requirement for producing good quality pipe welds. The highest priorities when selecting welding equipment for pipeline welding are reliability, consistency, accuracy and process control. It is also critical that the equipment is easy to use and the controls are intuitive. In addition to equipment performance, the work environment also needs to be a key factor for equipment selection. There are pipe welding configurations designed for offshore welding, remote land based pipeline welding, general fabrication shop use and custom configured automated pipe welding systems. Selecting the right one can be a daunting task – it is always good practice to seek expert advice. Be sure to ask about the various options, capabilities and limitations of each system. When welding CRA (Corrosion Resistant Alloy) grades, it is necessary to use weld purging in order to guarantee the corrosion performance of the root run. The importance of this should not be underestimated.
Welding inspectors have a responsibility to the company they work for and the general public to ensure that weld quality is satisfactory. Failure to fulfill their duties can result in property damage, injury, and death. Most welding inspectors, therefore, take their job very seriously. Welding inspectors spend years honing their ability to detect and size welding discontinuities and defects. While they must be proficient at identifying all discontinuities and defects, some of these weld irregularities are more readily detectable than others.
1. Surface Porosity
Porosity is gas that has been trapped in the weld; this results in cavity formation within the weld. Porosity can cause reduced weld strength. Welding inspectors who are not trained in other forms of nondestructive testing are limited to viewing the surfaces of welds. So while not all forms of porosity can be detected by a welding inspector, porosity that extends to the surface of the weld can.
“We were grateful to be able to see a product demonstration for the Red-D-Arc (Orbitalum) system. The machine lived up to its expectations and the technical team was invaluable”
—Rob B. (customer)
Update: Red-D-Arc now offers Orbital Welding Equipment from Axxair.
One of our clients, a machine shop based out of Opelika Alabama, needed a solution for welding stainless steel tubes and elbow sections efficiently that would be able to withstand hydrostatic testing of up to 300psi. After taking the time learn about their requirements, specialists from the Red-D-Arc branch in Austell Georgia, worked alongside experts from Airgas to demonstrate how the Orbitalum enclosed orbital welding system would help solve their challenges.
Red-D-Arc welding specialist Gregory Bellamy showed how the extremely narrow design of the Orbiweld 76S enclosed weld head was ideally suited for working in situations where space is limited. The Orbimat 76s was fitted with clamping shells (which are available for all dimensions of pipe) to ensure an exact match and strong hold. The pipe on this application was stainless steel tubing 1.500″ with a .035″ wall, diameter tubing (straight tube) and stainless steel elbow 180 degree 1.500″dia. with a .049″ wall. When the welds were complete, the welded pipes passed the hydrostatic testing at upwards of 300psi.
Thanks to Gregory Bellamy and Rob Storch from Red-D-Arc as well as Wayne Blamire and Bill Hatter from Airgas for their support on another successful orbital pipe welding customer demo.
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