Pipe welding root pass change
How do you increase quality, reduce costs, increase productivity, and motivate your workers? Change your approach from traditional methods to find the answer. Welding productivity can be significantly boosted by this change.
As part of the welding process, pipe shops use argon back purges – which consume time and increase costs. It will save time and generate savings if the back purge is eliminated.
Pipe companies that switch welding processes and upgrade their welding systems are able to double the number of welds completed every day without compromising quality, allowing them to complete more jobs and meet tight deadlines.
Welding stainless and carbon steel pipe
Before: Back purging stainless steel pipe
The traditional welding method for stainless steel pipe involves a TIG root pass combined with an argon back purge, followed by a flux-coated fill pass and a cap pass. This does not optimize welding productivity.
In stainless steel, back purging required about 20 to 30 minutes depending on pipe size to set up argon shielding gas and tape the pipe ends. Additionally, back purging with argon gas added to consumable costs.
Swapping leads and polarities when switching from TIG welding for the root pass to flux-cored welding for the remaining passes also kills productivity.
After: Eliminating back purge with a multiprocess welding solution
The PipeWorx 400 is a multiprocess system that can do MIG, TIG, stick welding, flux-core welding, and Regulated Metal Deposition (RMD®), a modified short-circuit MIG process.
In stainless steel pipe welding, PipeWorx allows contractors to replace a TIG root pass with an RMD root pass using high silicon wire from Hobart, eliminating the need for costly and time-consuming back purging, thus improving welding productivity. In RMD, the metal transfer is precisely controlled, which provides uniform droplet deposition, making it easier for the welder to control the weld puddle. A controlled metal transfer and faster puddle freezing result in a less turbulent puddle, and the shielding gas exits the MIG gun relatively undisturbed. Shielding gas can then pass through the open root, displacing atmospheric pressure and preventing sugaring or oxidation on the back side of the weld. Since the puddle freezes so quickly, such gas coverage is only needed for a short time.
Productivity doubled through welding
Welding stainless steel pipe without a back purge is a major time saver for pipe contractors, directly enhancing welding productivity. Welders could set up for the RMD root pass faster as opposed to twenty to thirty minutes for the back purge.
Further, wire-fed RMD welding is more productive than TIG welding, allowing operators to complete more welds in the same amount of time. An 18-inch pipe often took several hours to complete the TIG root pass and back purge, then the flux-cored fill and cap passes. RMD root pass without back purge followed by flux-cored cap pass takes about 30 minutes.
Pipe contractors can benefit from these time and cost savings, helping them compete for jobs and complete work more quickly.
Creating quality welds
The welding of stainless steel presents some unique challenges. Due to its thin nature, the material does not hold as much heat when welded as carbon steel does. With RMD, welders can prevent material burn-through by applying less heat, ensuring both quality and welding productivity.
RMD’s consistent flow will also appeal to welders. With its good penetration, it is more forgiving of changes in welding technique or an inconsistent gap between parts. It is possible for welders to stay in the puddle and go.
In comparison to short arc MIG, the RMD process doesn’t blow out as much as short arc MIG. The RMD process is more forgiving, so contractors can train new welders faster and produce quality welds sooner.
An easy-to-use setup
Training is also made easier by Pipeworx 400′s user-friendly interface. To change welding processes, operators simply push a button. With the “plug and play” nature of the system, new welders can easily use it. Welding productivity can be enhanced with such a user-friendly system.
Choosing a welding system that makes operators of all levels feel comfortable is essential.
Enhancing competitiveness
Making the switch to the RMD and investing in PipeWorx 400 welding systems will give companies a competitive edge by improving efficiency and reducing costs. The biggest benefit is the elimination of back purging when welding stainless steel pipes. This switch significantly enhances overall welding productivity.
