Pipe welding is like any other traditional welding process, but with a little trick. As you advance through your welding career, you will need to do various complicated welding jobs. So, learning how to weld pipes is necessary to avoid any mistakes or accidents.
This job can become even more challenging when it is welding pipes instead of flat surfaces. You will have to work on a wide range of tasks, using various metals of different thicknesses. Thus, learning how to weld pipe will give you a much better understanding of welding in general. It is, therefore, an excellent foundation for more complicated procedures.
As you move forward, you will find various necessary factors related to pipe welding procedures. This guide will let you in on some tips and tricks for pipe welding that will tell you how to weld pipe correctly. By the end, you will be able to start preparing as a pipe welder and having joints that pass stress tests.
Table of Contents
How welding works
Welding is to join two metal parts together or fill and repair holes on metal constructions through intense heat and gas. For example, fixing pipelines, bridges, power plants, buildings, ships, etc. are some welding jobs. Thanks to the almost universal need, welding is always in high demand worldwide.
There are more than 100 different welding types a welder can use. The three basic welding techniques available to modern welders are arc welding, AAS welding, and laser welding. Among these, arc welding is the most common. So, how does it work?
Brazing and soldering use a binder with a lower melting point, but welding joins the two workpieces together. Understanding this difference is necessary in order to comprehend welding. This is why it is preferred for durable, long-lasting construction.
In arc welding, the welder uses electricity to create enough heat to melt the work materials and filler material. And when they cool, they result in a binding of the metals. You need to attach a grounding wire to the welding material or other metal surface in this process. Then there is another wire called the electrode lead, which you have to place on the material to be welded.
Pulling this lead away from the material will generate an electric arc. This procedure requires steady hands and concentrated eyes. It would help if you acquired control over the process. As the rod melts, you must keep feeding the filler into the joint using small, steady, back-and-forth motions. Doing this too fast or too slow, or holding the arc too close or far away from the material can create inadequate welds.
There is a variety of welding tools that can be used for arc welding. Shielded metal arc welding (SMAW or stick welding), submerged arc welding (SAW), gas metal arc welding (MIG), and gas tungsten arc welding (TIG) all represent arc welding.
Which welding is best for welding pipes?
So, how to weld a pipe? Or more precisely, what procedure does pipe welding require? Pipe welding is among the most common welding types. It also has applicability worldwide, in almost every sector. Therefore, welding pipes is demanding. We have already mentioned that arc welding is the most common welding procedure. It is used for nearly every welding purpose. For pipe welding also, the most famous method is arc welding.
As a welder, you must know the most crucial thing about welding and pipe fabrication. Different grades of pipes require other processes. There are several different welding processes that welders must understand to get their job done in the best and safest way possible.
Arc welding is more durable than other welding methods. It is also safer. It ensures that the gap is fixed or the metals are joined as planned. And it also lessens the threat of any further issue. However, one must concentrate during the process. Joining the metals requires a comprehensive movement that is not hurried. Otherwise, there can be imperfect joining.
The two most basic arc welding procedures used for pipe welding are metal inert gas welding (gas mal arc welding or MIG) and tungsten inert gas welding (tungsten arc welding or TIG). MIG is the most common type of arc welding. This welding is excellent for mild steel, stainless steel, and aluminum. It is also the quickest form of welding since it does not require any mixing of gases.
TIG or tungsten inert gas is a more expert form of arc welding. It is excellent for many metals, including alloys. This procedure produces clean welds. Therefore, there is no fear of unprofessional results. TIG is a much faster welding process than MIG and can be used more frequently.
Tools required for pipe welding
To know how to weld pipe, one must get acquainted with the instruments required for the job. For proper pipe welding, you must have the best equipment, both on-site and in the workshop. There are several necessary pipe welding tools that a welder would need for the job from pipe handling to fix. To make the process easier , we have listed them below.
1. Welding machine
The very first thing you would need to weld a pipe is a welding machine. This machine fuses two piping parts using a high-ampere electric current and a welding stick.
Tools for pipe handling
Pipe jacks: These are useful pipe stands for professional handling.
Pipe carts: These are useful in transporting the pipe.
2. Tools for pipe welding alignment
There are several tools that we use for pipe welding alignment. Depending on the type, material, and size of the pipe, these tools vary. Some of the pipe welding alignment tools are pipe welding clamps, C clamps, hydraulic external pipe clamps, pipe chain clamps, mechanical cage pipe clamps, and internal pipe alignment clamps.
3. Electrode ovens
Electrode ovens are used for rebaking or for storage of welding electrodes under moisture-free conditions.
4. Pipe purge system
A pipe purge system plays a vital role in removing water vapor, oxygen, and any other gases or vapors from the joint’s vicinity that might be harmful to it. Thus, it is recommended that you purge the stainless steel pipe before welding.
5. Oxygen analyzer
It is necessary to take the proper measurement of the welding environment before starting the job. An oxygen analyzer is a handy tool for the job. But first, you must calibrate it according to the average oxygen concentration in the air (20.9%).
Steps to welding a pipe
Pipe welding is not an easy task. There are specific rules, positions, and procedures that one must follow. As you have had a basic knowledge about pipe welding, it’s time that we learn how to weld pipe. The most common process of pipe welding is open root welding. It is also tricky, as you will be fusing across a gap. So it is vital to use the right technique so that you do not make a mess of the whole job.
1. Pipe welding techniques
There are several passes used for welding a pipe. Root passes are the most common that fill the gap between two sections of piping. GMAW passes use an open root weld with no backing ring.
Hot passes use a single weld that attaches the root weld with both channel faces. Then there are manual passes that are continuous all the way around and through the tack welds. Fill passes work as their name suggests. It means they should fill every groove almost completely.
2. Prepare yourself beforehand
Once you have learned about the different welding techniques, it is time that you prepare yourself ahead of the job. Welding can be a dangerous job if not executed correctly. Therefore, you must take all the safety precautions. Wear the proper suit and take the necessary equipment.
Arrange all the tools you need to weld the pipe. While performing the task, make sure you keep them near you. Also, make sure the pipes are sanitized. Do check the oxygen level before starting your job.
3. Know welding positions
Proper welding requires the correct position. The position of your pipe can determine your position. A system of letters and numbers that acts as a code indicates which joint type and position you should use.
For instance, there is an F for filler welds. But, filler welds are way more uncommon. Groove welds are the most common and identified with the letter G. There are four prominent pipe welding positions, numbered 1, 2, 5, and 6.
1. 1G Position
It is a rarely used position, but significant enough to mention. It is flat welding, where the pipe lies on its side. Thus, you can rotate the pipe when you weld. To weld in this position, start your arc in the center of your tack. You should be in the center of the puddle as the pipe rolls away from you.
2. 2G Position
It is a fixed position, which means you cannot move the pipe as you weld it. Keeping it on a base would make it sturdier and easy to weld.
3. 5G Position
The 5G position is almost similar to the 1G position, except that you can’t move it. So, it requires you to weld in a variety of different situations, including overhead. You can start welding the arc in the center of a tack weld with a 5 to 10-degree drag angle and stick out the length.
4. 6G Position
It is the most challenging position, as it requires welding at 45-degree angles. You need to weld the pipe from every direction, which is the real challenge.
Knowing the proper welding position would help you understand the challenge, and thus, you can act accordingly.
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Test your pipe
So, the final step is testing the welded pipe. There are several ways in which you can do it.
1. Visual inspection
The fastest way to test your pipe weld is by inspecting it visually. In this process, you see the welded portion and try to observe its condition. But this process is not foolproof. There can be holes that are not visible to naked eyes.
2. Macro etch exams
In this process, you spay or brush a liquid dye on the pipe weld that highlights surface cracks or imperfections, invisible to the naked eye. So, it is more reliable than regular visual inspection.
3. Electromagnetic test
Electromagnetic testing is the most reliable and only practical way to detect internal weld defects. Therefore, this technique is used by professionals where the quality of the weld is essential.
Welding safety precautions
Knowing how to weld pipes does not ensure your safety. Rather, it increases the risk if you don’t follow the safety guides. Welding pipes can be hazardous if one does not follow the safety rules. They say, “Prevention is better than cure”. We care about your safety. Hence, make sure you follow these safety tips mentioned below.
1. Always wear the proper PPE
PPE or personal protective equipment plays a vital role in your safety. If you are a welder, you must always consider working with a proper PPE. Don’t avoid wearing a helmet, respirators, boots, gloves, and most importantly, fire-resistant clothing. Please avoid rolling up your sleeves or removing your helmet.
2. Get proper training
A welding job is not a child’s play. A minor distraction or carelessness can cause severe havoc. So, proper training is necessary to do the job safely.
3. Do not keep any flammable material nearby
While welding, you should never keep any flammable objects nearby. Sparkings, heat and molten metals produced from welding can set those items on fire.
Why should you consider welding pipes?
After knowing how to weld pipes, you might want to know the benefits of such labor. We agree that pipe welding is a tiresome job and needs much effort. However, considering the benefits, it is worth it.
1. Durable
Welding is more durable than screwing two pipes together. In this process, you use long-lasting filling. It ensures that your pipes are stuck together, no matter what.
2. Cost-effective
Changing a pipe is no option when you can fix the defect. Unlike screwing, welding is cheap and does not require much equipment. Therefore, welding is a far more cost-effective procedure.
3. Smooth flow
If there is a screwed finish, there will be more resistance to fluid flow in the pipe. But the welded pipe has a smoother finish that ensures smooth flow without much obstruction.
Conclusion
If welding is your passion, or if you love the job, mastering this skill will boost your welding career far beyond the potential of a hobby. Welding is typically in high demand worldwide. By choosing welding as a career, you can touch the heights of success. With the proper dedication to learning how to weld pipe, you will learn some of the most challenging welding techniques. Alongside, you will also acquire a highly prized skill set that employers desire.
These tips and tricks on how to weld pipe should be enough to get you started. But with all this, you must also get proper training and follow all the safety precautions to avoid any serious injuries. That said, it is time that we say bye till we meet again.