Note: This article first appeared in BIC Magazine
In industry, a growing trend is the idea to use orbital welding as a solution to the mounting problem of welder shortages. It is a well-known fact there are just not enough pipeline welders to go around (no pun intended). By 2020, the American Welding Society expects the U.S. will face a shortage of 290,000 welders. Companies in other business sectors — from food service companies to banks — attempt to solve labor issues and increase efficiencies by utilizing automation to replace workers. Is automation, specifically orbital welding in this case, the way to improve operating factors and productivity?
Look Upstream to Material Fit Up
The first part of improving welding operations is not to look at the welding process but instead examine its upstream aspect at material input. Material fit-up is the first key to improving quality and productivity. Poor fit-up causes overwelding and often leads to weld quality issues. A fillet weld that requires a quarter-inch weld has an unintentional root opening or misalignment of 1/16 inches. It then requires a 5/16-inch weld, which in turn increases weld joint volume by 57 percent. This result means 57-percent more wire, 57-percent more gas, 57-percent more use of consumables and — the most costly issue — 57-percent more time to weld that joint.
Let’s say that same 5/16-inch weld is then welded within tolerances, but the weld size is overwelded by 1/16 inch. That 5/16-inch weld then becomes a 3/8-inch one due to the compounding factors of material fit-up and a very common practice of overwelding. This weld that could have been done to code and adheres to a welding procedure is now 100-per-cent more costly than intended.
Are you buying double the gas and wire you need? Eighty-percent of most welding operating expenses are in labor. What are you paying to have someone weld 100-percent more than what is needed?
What is paramount is we can create precision fit-up and limit overwelding with the use of end-prep and orbital welding. Regardless of welder skill or the type of welding equipment, starting a weld with poor fit-up will result in a weld that costs more to produce. The conversation about quality, productivity and efficiency should not start at orbital welding or about your welder’s skills but should instead begin at end-prep. End-prep equipment, simple to operate and often overlooked because of its necessity, offers machine shop-like precision and fit-up while in the field. With the unfortunate skill gap widening in the trades, it is imperative to start your pipe or tube welding with precise fit-up, as those who can make passable welds become fewer and fewer.
We aren’t replacing welders with automation; we are making them more efficient. The goal is to take the welder you have and select the proper end-prep and orbital welding process for your job so you can possibly create twice as much time for him or her and improve quality along the way.
Meeting the Challenge of Welder Shortages
In order to meet the rising challenge of the lack of qualified welders, we need owners and management as well as welders to come together to increase quality and productivity. Management needs to provide welders with good material and proper equipment to work with, and the welder needs to realize we aren’t attempting to take his or her job but instead attempting to give him or her the best tools to get the best result.
When you look for a company to fulfill your business’ welding needs, you should search out a supplier that offers more than just equipment. Find a supplier that offers not just a few options of welders but solutions.
For more information, visit www.red-d-arc.com, call (866) 733-3272 or email Brian Imhulse at Brian.Imhulse@airgas.com.
Stainless steel contains a minimum of 10.5% chromium which imparts it corrosion resistance by forming an oxide layer on the surface. The most common stainless steel is the austenitic type (300 series) which contains chromium and nickel as alloying elements. Other types include ferritic, martensitic and duplex stainless steels. Most stainless steels are considered to have good weldability characteristics. Most common processes used for welding stainless steel are TIG (GTAW) and MIG (GMAW). But, stick welding (SMAW) is also utilized.
Differences in Properties:
The properties of stainless steel differ from mild steel, and these differences need consideration when welding as below:
- Higher coefficient of expansion, 50% more for austenitic – this results in more distortion
- Lower coefficient of heat transfer – welding requires lower heat input as it is conducted away slowly
- Lower electrical conductivity – using the correct and consistent stick-out distance is more critical when using MIG/TIG, higher wire speed for the same current is required when MIG welding
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.”
We are pleased to announce the launch of a new product in our weld automation category. Red-D-Arc now offers adjustable pipe stands with a carrying capacity of up to 4 tons, in both low and high profile versions. Combined with our turning rolls and positioners, these stands offer an effective solution for supporting pipes during the welding process for both manual and automated applications.
“Pipe stands with a carrying capacity up to 4 tons… low and high profile versions available.”
Our pipe stands feature polyurethane rollers and have been fully UL and CE tested. All of Red-D-Arc’s weld automation equipment has had its weight capacity UL verified to ensure safety and quality. This is a first in the weld automation industry.
2 Ton Adjustable Height Pipe Stands
4 Ton Adjustable Height Pipe Rollers
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.