This tool, as shown on the pictures, is used to clamp two pipes.
It is used when you are welding two pipes and you want to form a butt weld. The tool consists of several parts. Two identical round parts are bolted together with screws and nuts and they are tighten around one pipe. There are 3 other parts that are welded on those round parts and they have a threaded hole M5 trough them. Trough these holes we put screws, as shown on the pictures, which main purpose is to center and tight the other pipe so that it is aligned with the first one. After that you can weld(staple) some small portions of the pipes to make them joined. Than you remove the tool and you complete the whole welding process.