The most obvious reason why welders and plumbers need to use pipe welding clamps is to prevent committing errors in the fusing alignment of two pieces of metals during welding.
In the metal fabrication workplaces, employers also urge their welders to use these clamps not only to achieve perfect metal alignment but these can also prevent injuries to workers especially when fitting large and heavy metal pipes. Back injury is most common to welders that attempt to fuse heavy metal pipes without assistance. Aside from that, it takes a lot of labor time trying to weld metal pipes without the use of pipe clamps.
The other uses of pipe clamps for welding is to aid welders in reforming or repairing the misalign sides of the pipes that were previously welded. So you can also use these clamps in aligning and reforming elbows, flanges, tees and other fittings that were incorrectly welded. For orbital welding, pipe welders also use pipe fitting clamps in holding tubes to have that perfect alignment while the machine automatically weld the pipes in circular motion.
It is very easy to learn how to use pipe alignment clamps and once you get to use it you can also do full circle welding without removing the tool. You can also use the pipe clamps on a variety of metal pipe products such as stainless steel and steel alloys that are commonly used for piping.