A end cap is a closure device used to cover the end of a pipe. It is designed to protect the pipe from debris, moisture, and other contaminants from entering the pipe. End caps are available in a variety of materials, including plastic, metal, and rubber. The most common types of pipe caps are threaded, slip-on, and weld-on. Threaded pipe end caps are screwed onto the end of the pipe, while slip-on pipe caps are simply slipped over the end of the pipe. Weld-on pipe caps are welded onto the end of the pipe for a more permanent seal. Pipe caps are used in a variety of applications, including plumbing, HVAC, and industrial piping systems. They are often used to protect pipes during transportation and storage, as well as to prevent leaks and damage to the pipe.