Flow Plan Arrangement

 Flow Plan Arrangement

The flow plan should be arranged in a logical order of flow. The main flow through the unit should be obvious by even a brief examination

of the flow plan. 

Use the following checklist as an aid when developing a flow diagram.

• Avoid crossing lines where possible.
• Space equipment on the sketch to avoid overcrowding.
• Use notes with symbols where necessary for clarity.
• Use arrows to show flow direction.
• Show equipment numbers when it is necessary to identify equipment.
• Show control systems on the sketch. The control scheme is frequently the most important part of a flow plan sketch.
• Show important valves, orifices flanges, and control valves.
• Show flow directions through exchangers with arrows.
• Do not run lines diagonally across the drawings.
• Label feed lines entering the unit from the field where the line enters the unit. Label product lines leaving the unit by name.
• Do not draw lines any closer together than necessary.

Piping Symbols:

• Valves are drawn in same size no matter the pipe size and pound ratings.
• Nozzles and Reducers are not shown on the P&ID diagram.
• Symbols used on flow diagrams represent the actual piece of equipment.

Line List:

Line list is a document prepared by process engineers. Each line in a unit is listed in the list.

Line List includes:

• The number of the line
• Line Size
• Material of Construction
• Conveyed fluid
• Pressure, Temperature, flow rate
• Test pressure
• Insulation & Jacketing
• Connected line 

Sample Line List is given below:

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