End caps and pipe caps are very similar in appearance; their main differences lie in their inner diameter and application. Pipe caps are simply plugs for pipes, typically not exceeding DN300. If the DN exceeds 300, end caps must be used instead. Theoretically, end caps can be made infinitely large, but the equipment limit is generally around DN6000.
End caps are used in various container equipment, such as storage tanks, heat exchangers, towers, reactors, boilers, and separation equipment. Pipe caps, on the other hand, are used to seal pipelines, serving the same function as pipe plugs, and are generally used under lower pressure conditions to facilitate disassembly and maintenance. Pipe caps are generally not used under high or medium pressure conditions.