Expandable test plugs for purging and general pipe blocking Pipe stoppers, or drain plugs as they are sometimes known, are used to temporarily seal the end of a pipe or opening for many different testing applications. Pipe stoppers are mainly used to seal off water, gases and foreign objects in newly laid pipes, or pipework systems that are under repair.
These steel plugs are typically suitable for more arduous duties such as long immersion in water and use at higher temperatures or for contact with acidic or alkaline environments for which the Nylon and Aluminium plugs may be unsuitable.