Typical content of a process flow diagram
PFD_Symbols.png
Process flow diagrams of a single process unit will typically include the following:[4]
Process piping
Major bypass and recirculation lines
Major equipment symbols, names and identification (either by name, number or both)
Flow directions (indicated by arrows on the process streams)
Pressures and temperatures, as well as other control valves and systems that monitor and control the operation of the process (shown schematically, rather than in complete detail)
Interconnecting lines with other systems (if any)
Pressures, temperatures, flow rates and other pertinent operational values for each of the equipment items such as pumps, gas compressors, distillation columns and other vessels
In some cases, the process flow diagram includes a material balance that lists the normal temperature, pressure, amount and composition of all the major process streams. Also included, in some cases, are the amount of heat provided by any process furnaces and the amount of heat exchanged by any process heat exchangers.
The adjacent drawing depicts some of the typical symbols[5] used in a process flow diagram to indicate the major equipment items.