Process Flow Diagram Checklist

This short checklist will help you when drawings a Process Flow Diagram and the associated heat and material balance (aka stream table). This is a sister article to my Process and Instrumentation Diagram Checklist.

Items to check:

• Page number
• Revision number and revision purpose
• Sign-off information (such a drafter/designer/checker/approver) is correct
• All dates
• Drawing Title-block
• Notes/holds are there and correct. Check spelling, placement. Ensure any project-wide notes and holds are present.
• Stream Table – latest data, correct units of measurement, all necessary streams are listed
• Stream Table – quick logical spot-check:  vapor lines don’t have liquid flowrates or vice-versa, low pressures do not flow into high pressures, mass balance closes, two sides of an exchanger have the same change in enthalpy
• Stream Table – any notes and holds required are there and spelled correctly. Document number, revision, date etc. are in place
• Stream Flags/Tags are placed well and match the stream table
• Avoided bends/doglegs in all piping and instrumentation lines where possible
• Borders all visible, drawing centers
• Equipment Tags Correct Format
  Equipment Tags Correct Names, matches equipment list, P&ID, etc.
• Equipment Tags Placed Well
• Instrument types and logic is shown correctly. Level of detail is appropriate for a PFD
• Legend is Correct
• Old/New lines and items are differentiated correctly (if applicable)
• Lines break correctly (most companies follow the rule that control lines break for process lines, and vertical lines break in preference to horizontal lines)
• Correct lineweights, arrow size, line patterns
• In/Out Stream flags (aka Off Page Connectors) match across all drawings, correct text and spelling, correct drawing references
• Streams enter the drawing from the left side and exit from the right side where possible
• For any revisions to a previous drawing, take a quick glance to make sure changes from the previous revision are correctly in place, and that the redrafting did not introduce any new errors. (Which could occur even in areas that were not changed)
• Take a highlighter and trace over everything once. This will force you to find final errors