Trunnion is 1) an additional pipe, similar to the size of the parent pipe that is welded to an active piping system in order to add physical support; 2) a part of a ball valve that holds a ball on a fixed vertical axis and about which the ball turns; 3) one part of a rotating joint where a shaft is inserted into a full or partial cylinder.
Related Definitions in the Project: The Piping and Pipeline Engineering
