Welding small diameter tubing can be difficult. The tight radii often require expert welders to deliver precise torch manipulation with finesse. If the welder is not skilled enough, the out of position areas are at risk of poor quality due to gravity affecting the weld pool and ineffective torch angles. If out of position welds cannot be completed satisfactorily, the part must be rotated. However, some assemblies can’t be rotated because of size constraints or they might rotate off of center. If a mechanized welding solution is desired for small diameter components, look no further than our Axxair Orbital Fusion Closed Welding Head Systems.
Closed-Head Pipe Welders
Axxair Orbital Fusion Closed Welding Systems are comprised of two main parts: the
Axxair Orbital Fusion Closed Welding Head and the Axxair Orbital Inverter Power Supply. The Orbital Fusion Closed Welding Head fully encompasses the assembly being welded. This means that an inert gas environment can be created around the part, preventing it from the risk of oxidation that it might be exposed to during a welding operation that relies solely on a gas nozzle. The Orbital Fusion Closed Welding Head also has a ring drive that enables full 360 degree motion around the weld joint, all the while keeping a consistent torch angle. Furthermore, it is capable of going over 360 degrees for when slope-in and slope-out parameters are needed.
“The Orbital Fusion Closed Welding Head also has a ring drive that enables full 360 degree motion around the weld joint, all the while keeping a consistent torch angle.”
The method you select for welding pipe will depend on the location where the welding is taking place, materials and pipe size.
For welding steel pipes in the open (e.g. pipe installation in trenches), manual arc welding (SMAW) is most common. This technique used is downhill using cellulosic electrodes (also basic electrodes are used for higher strength steel applications). A root pass and a hot pass are followed by the fill passes. The weld is finalized by the top pass. Welding units optimised for downhill welding are utilised.
Welding Smaller Pipes
For small diameter and short length pipes which are free to rotate, the pipe is rotated while the welding torch is held stationary. The processes used are MIG (GMAW) and TIG (GTAW). In the case of TIG welding a wire feeder is necessary. A process cell is best for this type of welding.
Welding Large Pipes
In applications involving larger pipe sizes, welding is generally carried out using the orbital process. MIG is usually employed, but TIG with automatic feed of the filler wire can also be used. Orbital process using closed head welding units is also utilized for applications where smaller pipes cannot be rotated.
There are a number of advanced methods of depositing pipe welds currently in use. These include precisely controlled short circuit transfer for root pass (Miller – Regulated Metal Deposition), optimized pulsed welding (Miller – Pro-Pulse) and high frequency waveform control (Lincoln – Surface Tension Transfer) in order to speed up and improve the quality of the pipe welds.
Red-D-Arc has a wide range of pipe welding equipment for rent including the following:
- Closed head orbital welding units for small pipe diameter
- Orbital TIG welding system for larger pipe diameters
- Orbital MIG welding system
- Process pipe cell with oscillating open arc welding
- TIG and MIG welding power sources suitable for above
- Cutting and bevelling saws for up to 12.75” (325mm) pipe diameter
Have a look at our entire selection of pipe welding equipment which includes pipe cutters and bevelers.
It’s a great day in Tulsa
It’s a beautiful day in Tulsa Oklahoma. – April 4, 2018
Drop by booth #507 and check out our Orbital Tig and Induction Heating systems. We’ve got a beautifully reconditioned 300 amp Red-D-Arc Diesel welder for sale with special show pricing!!
Don’t forget to scan your badge for PennWell Drone Draw!!
www.pipelineenergyexpo.com – April 3-5, 2018
By guest Blogger Katarzyna K.
Katarzyna has an Msc in Materials Science and has worked in the oil and gas industry in jobs related to hydraulics, welding and the retrofitting of oil rigs.
Stainless steel is used extensively in the petrochemical industry due to its high resistance to severe conditions. When welding inox steels, the smallest details matter and have an impact on weld quality. The following are some tips for stainless steel pipe welding based on my oil rig repair experience:
During an oil rig repair project that involved 2205 duplex stainless steel pipe TIG welding, we could not achieve the required weld properties. Despite using the recommended filler metal with higher nickel content, compared to the base metal, and controlling the interpass temperature, the weld tensile strength was still too low. In order to reach the required weld quality we dug deeper and found a solution – (more…)
“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.