Being a professional welder requires the ability to tackle a wide variety of jobs and becoming familiar with lots of materials of different thicknesses. There are numerous challenging processes to learn when you are making a break into professional welding, but pipe welding is one of the most difficult yet common you are likely to come across. This means that you will need to be able to join cylindrical metal tubes using a gas shielded arc welder or a shielded metal arc welding technique.
The main challenges associated with pipe welding are related to the positions that you will need to be in an order to tackle the job, as well as the skills required to master the techniques needed for obtaining the best results. The good news is that welders who manage to excel at pipe welding tend to earn more than those who only employ other welding techniques, simply because 6G pipe welding is rather difficult to master.
Essential things to know about 6G pipe welding
The most common process that you will have to use while pipe welding is open root welding, which essentially means that the welding joint does not use a tacked backing plate. As you will actually be welding across a gap, the technique is rather difficult to master, so it is essential to employ the correct technique in order to avoid making a mess of the entire job.
One thing to note is that as you move around the pipe in order to get access to the gap you will be blocking your view with your own hand at one point or another. For this reason, you need to determine which is your good and which is your bad side when it comes to welding. This is correlated with whether you are right-handed for left-handed.
If you are right-handed, you will find it challenging to work on the left-hand side of the pipe and the other way round goes for those who are left-handed. By being able to anticipate this obstacle, you will learn the best way to overcome it in order to make sure you do not mess up the job and get a smooth weld every time.
To make things easier, start by tack welding your materials together in order to ensure that they are secured in their place, so you have the time to focus on the actual welding. you can also reduce the amount of defects in the final weld by cutting out and feathering your tacks. You also need to know that if you want to get the best results, you should never start or stop the welding in the gap - instead do so on the side wall.
Imagine that the pipe is a clock face divided into sections, and this way you will be able to work away from the 12 o'clock position to 3 o'clock and repeat the process in four steps until the weld is entirely complete. Make sure that all of your tacks are tied in securely as you progress.
Finally, you need to be aware of the fact that poor penetration can be quite a problem if it is not done correctly. Achieving the right level of penetration can indeed be difficult because pipe welding usually uses heavy duty, thick materials. It is of utmost importance to realize that if you leave poorly penetrated welds on an industrial pipe welding job, this may end in disaster. As such, you need to be absolutely sure that you achieve full penetration when welding, and even use a groove weld if you find it impossible to weld from the inside of the pipe as well as from the outside.
Dealing with pipe welding positions
Mastering the right positions that will allow you to achieve the best results is extremely important when it comes to pipe welding. The system of numbers and letters that you can see on pipes is the code that indicates what kind of joint type and position you need to use. For example, groove wells, which are quite common, are identified with the letter G.
The four main welding positions are numbered 1, 2, 5 and 6. The flat welding position is number 1G, but you will not use it very often, even though it is still important to know about it. The 2G position means that you cannot turn the pipe as you weld and you need to place it on a base that makes it more stable and stronger to weld.
Similar to 1G, the five-year position means that the pipe is placed horizontally but you cannot move it because it is fixed. In this case, you will need to weld in various different positions, which often include overhead. You will most commonly use vertical up and logical down directions for this type of welding.
The most challenging position is 6G, because in this case the pipe is fixed at a 45° angle. This is the kind of welding that requires you to pay particular attention to your good and bad side discussed above because you will not be able to weld without blocking your view with your own hand. Finally, if you notice the letter R in any welding code, this is an indication of a restricted wedding position, which can be a visual or physical one.
Tips for testing your pipe welding
No matter the reason for which you want to test your pipe welding as well as the quality of the final weld, there are a couple of ways in which you can do that. The first one, which is the most common and easiest to do, is inspecting the weld visually. Even though this is the cheapest and easiest way of testing were pipe welding, it is important to note that it can be a subjective process and you cannot use it as a reliable method when it comes to spotting various internal defects. This is a good method to use in those situations when a potentially poor quality weld will not put anything or anyone in danger.
The second method that you can use, which is just marginally more expensive, is testing with a liquid dye penetrant. All you need to do is spray a dye or brush it on the surface of the metal in order to highlight any imperfections or surface cracks that are not visible to the naked eye.
The only real method that allows you to detect internal weld defects is x-ray testing but this is not something that you can use on any job. Reserved for those jobs where the quality of the weld is particularly important for safety reasons, this method works in a similar way to medical x-rays, but on an industrial scale. You need to be a trained professional to use this method because there are multiple risks associated with it. Moreover, this is the most expensive method to test for weld defects.
All these methods do not cause any destruction to the pipe. There are, however, situations in which you need to break apart the pipe weld and separate it into multiple sections in order to be able to test their strength and the quality of welding for each one.
Most welders that tackle a pipe welding job for the first time are terrified by the idea that something went wrong and they need to face the consequences. It is important to know that even if you mess up and your weld is not strong enough, it is not that difficult to repair an open root weld. You first need to stop worrying about the entire pipe and grind the problem area down. Next, return that section to the same size as the original groove and then just re-weld it as normal.
If you want to get your certification as a pipe welder, you will need to pass through a rather demanding process, as you will need to prove not only that you are good with a welding machine, but also that you can produce quality penetration and that you are able to work in tight spaces with a restricted view. You also need to be able to pass a test regarding your all-position welding technique.
Pipe welding is a step further in your welding career and it is far beyond a hobby, so you need to understand numerous elements that make the job an important and difficult one. In order to be able to master the art of pipe welding, you do not need any extra special equipment beyond that of a regular professional welder, but you need to keep in mind that this is not an easy process, and you will need to make efforts to get better. In order to get a professional 6G certification, you may need to attend a reputable welding school, which may be time-consuming and costly. In the end however you will gain an extra skill that will definitely enhance your career.