Pipe end plug is a pipe fitting installed on the external thread of the pipe end to cover and plug the pipe, also known as pipe cap, cap, pipe cover, or plug. Its function is to seal the pipeline, which is the same as the function of pipe blockage. It can be directly screwed onto the pipe without the need for other fittings. A plug is used to seal pipelines, providing a sealing effect, and is suitable for media such as water, oil, and steam. It is a type of mechanical fastener.