This is used when it becomes necessary to keep an internal process at a particular temperature or physical state.
The system has two main components an internal process line and an outer line that envelopes the process line.
The process line in usually smaller and this is used to allow the free flow of a fluid within the system. It is used to carry the substance to be kept warm, at a specific temperature or state. The internal diameter of the connecting flange is sized to the internal diameter of the process line.
The outer line encapsulates the process line. The overall flange size, namely the outer diameter can be sized from the outer diameter of the outer jacket line.
The annular space between the process and the jacket line is where the steam is allowed to flow.
