Which component is NOT part of a pressure piping system?

In the context of a pressure piping system, the components are crucial for its functionality and safety. Pipes, bolting, and gaskets are all essential parts of such systems. Pipes carry the fluids under pressure, bolting is necessary to connect different components securely, and gaskets are used to ensure a tight seal between flanged connections, preventing leaks.

Insulation, while it may be present in some piping systems to maintain temperature or enhance energy efficiency, is not a required component of the piping system itself. The primary focus of a pressure piping system is to manage the flow of fluid under pressure and connect various system parts, which does not inherently include insulation as a core element. Therefore, the absence of insulation from the list of essential components identifies it correctly as the non-essential component in a pressure piping system.