Pipe welding or pipe fabrication is a method where two pipes are joined together. This process is achievable through different welding methods like Arc Welding, MIG Welding, TIG welding, and several other welding techniques.
Job opportunities for welders have risen over the years thanks to the booming industries.
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However, Pipe welding in industries requires skilled workers. Since welding is a complex process, the margin for errors to occur is quite significant.
Hence, precision and resistance are key in this field.
Mistakes in pipe welding can happen from both beginners as well as experts. Understanding them is the best way to prevent such occurrences from happening in the first place.
Mistakes in welding pave the way for weld defects. Recently, Honda had to recall some of their CR-V models because of a faulty weld that could result in fuel leakage. The Kursk Submarine Disaster is another example of how weld defects can cause massive harm to not just machines, but also human lives.
Pipe welding processes need to be on point because any mistake could result in a leak of the payload. Let’s look at some of the common mistakes in pipe welding that are common in the industry.
Preparation of the pipe is very important when it comes to pipe welding. There are only a hand few of welding processes that do not require workpiece prep before welding.
This preparation of the pipes begins with ensuring that the edges to be joined are smooth and uniform.
In many cases, the pipes to be joined would have undergone some sort of cutting or welding before it reaches the hands of the welder. So before the actual weld process, a surface grinding procedure is often used to get the edges right.
The next step is cleaning the pipes to remove any form of lubricants, oils or other contaminants present on the pipe surface.
Without following good pipe preparation practices, the weld is likely to face multiple challenges such as hydrogen inclusion, slag entrapments, and lack of fusion. These ultimately result in weaker welds and weld defects.
Even though the filler material will adjust to resolve minor alignments of the surfaces, there is a limit to what it can achieve. When parts aren’t joined at the right alignment, we see instances like a bevel with too steep of an angle.
Part fit-up is standard procedure in pipe welding. However, sometimes we see welders rushing the process and this creates misalignment welding defects that are both unsightly as well as structurally weaker when compared with a proper weld.
WPS or Welding Procedure Specification is a document that contains information targeted towards the welders, helping them with making welds that are in line with the code requirements. Too often, experienced welders ignore going through such documentation.
But that is not a wise choice. Pipe welding has many variables from the material of the pipe to the type of weld that is being used in the process.
A WPS will have all sort of information that is relevant to the welding process like weld type, welding positions, filler material classification, preheat temperatures, post-heat temperatures, weld treatment, and much more.
Referring to the WPS before starting the welding process is always a good practice.
Preparation of joints doesn’t have a universal procedure that you can follow. These procedures change according to the type of welding used.
Preparing a joint for stick welding is not as same as that used in MIG welding. They both require a different set of approaches and using the right one for the right weld is the only way you can ensure perfect pipe welds.
Without following the right weld procedure, you will end up with serious weld defects.
Shielding gas is used to present the weld from interacting with atmospheric gases like Hydrogen and Nitrogen. Many weld processes like laser welding use shielding gases to create better welds.
However, one among the most common misconception that many welders have is that more shielding gas will offer more protection. However, this is not true, and in some cases, it can even adversely affect the weld.
High-pressure welding gas at full speed wastes a lot of shielding gas without any advantages. Also, the force from the shielding gas can agitate the weld puddle.
It is always recommended to use a flow regulator to ensure that the weld receives the proper amount of shielding gas.
Many welders blame the power sources for the porosity in the welds. A power source cannot cause the weld to become porous.
However, other factors like changing the wire spool, using the wrong gas, or not prepping the workpieces often lead to porosity in the welds.
This goes to show that the welder must remain cautious at every step of the process to ensure good pipe joints. Things that appear seemingly harmless, such as the momentary disruption in a gas flow can create porosity in the welds.
Arc welding often causes the formation of slag. Flux coating plays a major role in creating slag inclusions.
Welders must use the correct speed and angle to ensure that slag production is restricted to minimal levels. Slag inclusion can also be prevented by using the right amount of voltage for the welding wire.
Cleaning between weld passes is another way you can prevent slag accumulation.
Pipe welding requires a strong and perfect weld. Why this is important is easy to understand because bad weld jobs result in leaks that can cause serious damages based on the fluid that it will hold.
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Hence, mistakes are not an option. As a welder, you need to make sure that each step of the process is done to perfection.
When you follow every single step with caution and perfection, you leave no room for error.