Tig-weld stainless pipe welding process 3PASS Hello. Today I made a video of the stainless steel pipe welding process. I’d appreciate it if you could press “subscribe” and “like.” So this is a 65A (2 1/2 inch) SCH10 stainless 304 pipe. Pipe thickness is 3.05mm. I’m going to weld this today. When welding these stainless steel pipes, it is necessary to “purge” the inside of the pipes. I did Purge this way. This is a stainless steel scrap. I put it together and blocked one direction. You don’t have to create a “Vent” And then the opposite direction of the pipe was argon gas. When you weld a pipe that’s this small, there’s a way to “purge” this way. This will slowly drain argon gas. When you check the amount of Purge gas, open the tape that you’ve put on it at 12:00. If you feel the wind escaping from there, you’ll have enough gas. But “purge gas” should not be too strong. We’re going to make a video of this kind of Purge gas later. So here’s the “gap.” This is a 2.4mm welding rod. So when I put the 2.4mm welding rod between the gaps, I made it this far apart. Now, next time… A subscriber wants to know how to use a large nozzle for narrow welding. So I prepared a big nozzle today. The nozzle has an internal diameter of 16mm. This is Big Nozzle 10. And tungsten length is about 8mm. I’ll set it up like this and weld it’s going to be welded. And I’ve made a very small tak weld. I’ve done “TACK-welding” in four places. So here’s the nozzle movement. The nozzle moves that way. It’s a step-by-step way of walking on top of a grooved groove. It’s different from how a small nozzle enters a groove and zigzags in another video. And if you show it in a continuous motion, it’s like this. Next is Purge Gas. Purge gas, if you feel argon gas flowing through the gap, is enough gas. When you start welding, you can attach the paper tape to it. But I’m going to remove all the tapes and weld them in order to shoot. You just need to know that there’s a way to weld the Purge. When you’re welding a smaller pipe, there’s a way to weld it without tape. But I don’t recommend a pipe that is about 65A size because it may not be Purge if you do this. I removed the paper tape because it would hide the screen if I welded it with a paper tape. But it’s safer when you’re actually welding with tape on it’s safer. Now we’re going to start welding. The current used 55 amps. Welding rod is 308. 2.0mm welding rod used. And the amount of argon gas is about 18 to 20. Purge gas is between 13 and 15. I remove all the tapes and I’m welding, so Purge gas is used a lot. However, if you are welding with tape attached, the Purge gas can only be used 7 to 8 times. And the gas gauge is not the correct size, so please bear in mind. When you weld this thin pipe, the nozzle is not allowed into the groove. So the nozzle has to be moved step by step, as if it were walking over the upper edge of the groove. He’s moving from the left corner to the right side. And when welding this thin stainless steel pipe, low current is used. When you use this low current to drag the melting pool… Tungsten should move very tightly, and it should only move as if it were glued to both edges by melting the rod. If you control the weld pool like this, it’ll help you keep the weld rod from the weld pool. Remember this feeling. It’s like moving the tungsten tightly and melting the welding rod to attach it to both corners!! This feeling is important. If you remember this feeling, it’ll help keep the welding rod from the melting pool, not separating. And now I’m using a 2.0mm welding rod. The reason for this is that when welding thin pipes, each layer used a thin weld bar to show more detail about the movement of the melting pool and tungsten. Welding will be done in 3 pass total. When connecting to a tack weld, it is recommended that the welds slowly be connected. Now we’re done with the ROOT PASS. It is also a good idea to check the height of the following welds after welding. So here’s what it looks like. Now we’re going to do a second weld. The nozzle has an internal diameter of 16mm. Tungsten length is about 8mm. It’s the same setting as the first weld. So I’m going to do a second weld like this. Second weld. The current used 70 amps. Welding rods used 2.0mm. The key to secondary welding is to melt the parts that were not penetrated during the first welding to create a solid penetration. And I think it’s a foundation to make 3rd welding more smooth and easier. The caution point for secondary welding may be that the back-bead will collapse or the surface of the pipe will be oxidized if the current is too high. There is a possibility of an “invasive defect” when using too low an electric current And with low current, it’s easy to control the heat input, but there’s also a downside to the weld rate being too slow. I think it’s better to take these precautions into account and make a compromise at the proper level. I tend to use as high an electrical current as possible on a line where the surface of the pipe is not oxidized. Even the 70 amperes we’re using now, the current is a little high. If you use the same 55 or 60 amperes as the first weld, you’ll have a more comfortable weld. The nozzle moves one step by one, like a nozzle on a pipe. It’s moving from the left corner to the right, and then to the other side. It’s the same as the first weld, but it’s moving wider. And the movement of the melting pool creates a clear penetration in the middle, and at both ends it melts the edges to create a smooth slope. If we weld like this, we’ll have a third weld… Welding only covers the molten part of both ends, which will help you to have a smooth weld. It’s a weld that feels like this. Now, finally, final weld. The current used 80 amps. Welding rod is 2.4mm. If the conditions for the second weld were good enough to make the final weld easier, When you do the last welding, you only have to feel like you’re covering both ends of the piercing groove. diagonally from left to right, from right to left… This is how you weld it, covering it with both ends. The supply of the welding rod is only sufficient to prevent the weld rod from being removed from the melting pool. If you only supply the welding rod with the feeling of pressing it on the floor rather than the feeling of supplying the welding rod, it will help you to achieve a constant level of welding. I used 80 amps. But the current seems a little high. I think it’s okay to use 60 to 70 amperes. So today, we’ve welded 65A SCH10 stainless steel 304 pipes. Welded at a total of 3PASS. When I was welding this thin pipe, I used 3PASS to show you the movement of the melting pool on each floor. I don’t think it’s a bad idea to use a thin welding rod to weld with 3PASS. And I’m sure some of you can watch this video and see that pipes that are about three millimeters thick can be welded with “2PASS.” And some of you think the back-bead is too high. So next time, we’re going to make a 2PASS-welding video of pipes of the same size with lower back-beads. So, I’m going to wrap up today’s My welding method is not necessarily the answer. But it’s one of the welding methods that we can apply in a variety of situations, so I hope it will help. I hope this video will help all welders grow and help us a little bit. Please press “Like.” If you “subscribe” and come to my channel, there are more different weld videos. Thanks for watching.