The term "knee piece" refers to a part of equipment that connects the upper and lower parts of a system, such as a pipe or a machine. Synonyms for knee piece include "elbow joint," "bend," "junction," "connector," "fitting," and "coupling." These words can be used interchangeably to describe the design and function of various types of connectors or fittings that are used to join different parts of a mechanical or plumbing system. Whether you are a plumber, a mechanic, or an engineer, it is essential to be familiar with the different terms and synonyms for knee piece to ensure proper installation and maintenance of the equipment.