What is known as the loose flanges?

Looper flange that is, the flange can be activities, generally supporting the drainage accessories (expansion joints on the most common), manufacturers factory expansion joints at both ends have a flange on the direct and project pipeline equipment bolted.
Looper is the kind with flange
Generally used in the pipeline, in which case, loose bolts can be rotated on both sides of the pipe, then tighten
Can be more easily removable pipe?