Cap

A threaded cap closes the end of a mating threaded component by fitting over its end; this connection principle distinguishes it from a plug installed into a threaded opening. It is also distinct from socket-weld and butt-weld caps. The title does not establish thread form, material, coating, pressure class, or reusability. Selection should verify mating-thread size and arrangement, sealing method, installation and removal clearance, the possibility of trapped pressure or fluid, and a safe maintenance-removal procedure under the project specification.