Stainless steel pipes are known for their durability and rust resistance. They can easily bear high pressure and are considered ideal for various applications. However, stainless steel pipes are welded to create a strong join between pipes. However, many people don’t know how to weld stainless steel pipes.
It is true that welding stainless steel is not a straightforward task. The reason is this material is very sensitive to heat. Upon welding, it can crack or wrap and reduce the quality of the weld. Therefore, understanding the right way to weld a stainless pipe is key. This article will give you steps to weld these pipes and create strong joints.
Types of Welding Used for Stainless Steel Pipes
Before going into how to weld stainless steel pipes, let’s first discuss welding basics.
Welding is a process of joining materials or pieces through heating. The heating melts the edges of the piece, and the welder attaches the pieces. Upon cooling, there becomes a strong bond between the pieces, and they stick together. The welding process is handy for creating strong joints between two metals.
Multiple welding types are available, each varying in workings and performance. However, manufacturers generally prefer TIG and MIG welding techniques. In TIG, tungsten is used as the electrode. This method creates very smooth, precise, and high-quality welds. Moreover, it uses pure argon gas, which protects the weld from deterioration.
However, this method is suitable for creating welding on thin pipes. Conversely, the MIG is ideal for joining thicker stainless steel pipes. Moreover, it uses a wire electrode, melts it, and creates a bond between two pipes. Unlike TIG, this method does not use pure argon as shielding gas. So, it does not generate the quality welds you get with TIG.
Instead, it uses a mixture of argon with other gases such as helium and carbon dioxide. Which method you should use when welding stainless steel depends on your preferences. Some people also use stick welding, which is very inexpensive. This method uses the metal rod as an electrode and helps create a strong weld.
Step-By-Step Guide: How to Weld Stainless Steel Pipes?
As I said earlier, welding stainless pipes is very challenging. The reason is that this material is sensitive to heat. So, when exposed to high temperatures, stainless steel can undergo wrapping or even cracking. Therefore, you should be very careful and follow the precautions.
In the section below, I will explain the welding process in steps. You should follow each step carefully to get the job done.
1- Clean the Pipes
First, clean the stainless steel pipes where you want to create weld. Generally, the edges of pipes are welded together. Right? So you should clean the edges and remove all the impurities, dust, and other contamination. Moreover, if you have any oxide layer on the surface, you should use a grinder to remove it. Remember, if you don’t remove these impurities, it might result in a weaker weld.
2- Choose the Welding Method
Choosing the right melting type is crucial. It defines the quality of the weld on the stainless steel pipes. What welding type you should choose depends on your desired output. For example, TIG welding is ideal if you want to achieve a high-quality weld with precision. However, this method is perfect for thin pipes. Moreover, it is slower and can take more time.
Conversely, MIG is a fast method that is ideal for thicker pipes. However, it does not create the high-quality welds you get with TIG. Some people also stick with welding because it is very affordable. It uses a metal rod as the electrode to create a weld. Remember, you can use any type to weld stainless steel. However, the weld quality they produce will be different from that of the others.
3- Set Up Parameters on the Machine
Each welding type uses a specific welding machine. For TIG welding, use TIG welding machines, and MIG uses MIG welding machines. However, there are some key parameters that you should set correctly. Those include amperage, voltage, and gas flow rate.
If the stainless steel pipe is thin, you should set the amperage to a very low scale. If you keep the amperage high, it will melt and deteriorate the pipe quickly. On the contrary, you should have a high amperage if welding heavier and thicker stainless steel pipes. Similarly, you should ensure the right shielding gas flow around 15–20 cubic feet per hour.
4- Tack Weld Following By Strong Welding
Once the parameters are set, it is time to start the welding. Switch on the machine (whichever you are using). Bring and keep the edges of pipes together for welding. Remember, if you use a TIG machine, you must feed the filler yourself during welding. So, hold the welding torch in one hand and feed the filler in the second hand.
The torch will melt the filler and create a joint (weld) on the pipes. In the case of a MIG machine, you don’t have to feed filler. This machine automatically uses wire as filler. You have to keep the touch on the spot where you want to create the weld. It is important not to start welding straightaway. In fact, you first create a tack weld.
Simply put, you should create a small weld at key points along the joint on the pipes. This small weld will be at regular distance from each other. These temporary tack welds help align two stainless pipes before creating the final weld. After making the tack weld, you can start welding the whole seam and create the final weld.
Quick Highlight: You should ensure that shielding gas goes on weld correctly during welding. Moreover, its pressure should be optimal to create a smooth weld. Remember, this gas ensures no air contamination on the newly made joint (weld). Moreover, it helps properly solidify the weld to gain strength.
5- Clean the Weld & Inspect it
The last step in this process is to clean the weld you just made. But why is cleaning necessary? It helps prevent discoloration and slag on the weld. Moreover, you’ll be able to remove the residue left on the surface of the weld. At a professional scale, the look of the weld matters.
Cleaning the weld makes it look smoother, not just a bad color spot. Moreover, you should also inspect the welding for cracks or holes. If you see any holes, it means you did not perform the welding correctly. So, you should bring a torch to fill those holes or cracks. However, if there is no crack, it means the welding of the stainless pipe is done correctly.
Frequently Asked Questions
What is the best welding method for stainless steel pipe?
TIG welding is considered the best option for welding stainless steel pipes. It is precise and creates a high-quality, strong weld. However, you can also use MIG and stick welding if you need fast speed and have a tight budget.
Can I weld stainless steel without gas?
Yes, you can do it, but I don’t recommend doing it. The reason is that shielding gas protects the weld against wrapping cracking and air oxidations. You should always use this gas to achieve a high-quality weld.
What challenges can I face while welding Stainless Steel?
Welding stainless steel is a challenging task that requires both skill and experience. This material is sensitive to heat. When exposed to high temperatures, it can crack, distort, and wrap, reducing the weld quality.
Conclusion
Stainless steel pipes are very popular across various industries. They are often used in water supply lines and oil transportation. However, pipes are usually joined together through welding. The quality of this weld defines whether the pipes will remain in good shape. However, many people don’t know how to weld stainless steel pipes.
In this article, I’ve discussed the complete welding process. You should follow the steps and create strong welding on the stainless steel pipes. However, be careful, as this material is very sensitive to heat. I highly recommend using shielding gas to ensure the quality of the weld.