Giant pipes are used everywhere in the world and it is the simplest way to pass huge amounts of liquid from one place to another. These giant pipes are used for the water supply from the river to the purification plant of your city, for natural gas pipelines, for food and beverages companies, etc. Welding pipes is not an easy task to perform, because it takes a lot of perfection to make it leak proof to avoid any loss or hazard.
To avoid any leakages welder needs to look into some common points like, cutting the edges, proper tack should be done, choosing the correct electrode/welding wire according to the base metal, need to check if he/she is using the correct shield gas or not and what should be the correct otherwise it can lead to more spatter, needs to understand the porosity and using the correct welding machine which can tackle the work.
Most commonly the steel pipes are used for any giant piping work, to weld the steel pipes together the welder can use metal inert gas (MIG/GMAW) process, tungsten inert gas welding (TIG/GTAW) process either shielded metal arc welding (SMAW) commonly known as stick welding process. The welder needs to align two pipes together in a way that no gaps will be left and this should be maintained during the whole process.
In the case of welding, the natural gas pipeline shielded metal arc welding (SMAW) process is very common and effective. Here the butt weld technique is used for the major joint. Here the welder needs to keep a few things in his mind like cleaning the rust, oil, slag to avoid any unfavorable events.
While welding pipes generally the tack weld technique is used to hold the weld before the final welding as it gives a blueprint to the welder of how the final weld will be done.