Some precautions to be taken while welding pipes, otherwise it will hazard the welding process and pipes as well. Welding process differs significantly depending upon the shape, material specification of steel pipe. Some kinds of steel necessitate pre-heating and pre-cooling in order to ensure crack and burst. MIG and TIG are the most reliable and effective tools for welding pipes besides propane torch. As we know that heat forms quickly on steel pipe, so the pipe gets hot enough to spawn burns in a short while. Purging with argon gas is the most critical part of welding steel pipes, this method is conducive to safeguarding the backside and inside of the pipes.
You make sure that there should not be even a small amount of water else it will thwart purging.
Make a vent into the upper part of the pipe and fill it with argon gas that will dispel water that accumulates in the pipe.
It is tremendously important to check the flow of argon gas, because the higher flow of purge gas does not mean that welding process gets quicker than a lower flow rate. More gas flow is not always useful, it sometimes devastates the purging work. So much gas is as bad as little gas. Set the rate of gas flow about 15 to 20 cfh, that actually depends on nozzle diameter.
Leaving the gap of 1/16th inch for weld between the two pipes is recommendable. Checking the quality of weld is the most important factors. If the weld gets oxidized, it gets infirm and may contaminate the product, and the repair of the oxidized pipe is expensive. Therefore stop oxidation by eliminating oxygen in the first place with the help of purging gas that is heavier than air. Purging gas not only removes oxygen but also protects the welded joint unless it cools off. It is crucial to keep oxygen below 70ppm in order to avoid damage to the weld.
It is advisable to heat up the end of the pipe, that will facilitate the welding process. Welding rods and solders are essential materials, generally used to bond during welding. Make sure that you should melt the welding rod onto the joint of the pipe. Propane torch is effective method to solder the joint. The entire area of the pipe joint should be covered during welding. Let the welded joint cool up. Eventually check out the soundness of the joint by exerting pressure on welded area of the pipe. Welding stainless steel pipe requires heat control that needs patience.