P&ID - Designer's Checklist

Detailed Engineering Drawings, Codes and Standards PIPING & INSTRUMENTATION DIAGRAM – DESIGNER CHECKLIST S/N

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ITEM DESCRIPTION My company’s document/drawing # Client document # Licensor/Vendor document # Title block: including the By/Approved/Checked blocks filled and signed, Date, Rev. all company logos, client signoff block? All equipment tagged, title above equip, spelling of names correct? Not crowded: Normally have about 4 pieces of equipment per drawing Where feasible, streams come in the left side and go out the right side fo the drawing. Battery limits are marked. Stream tags include the fluid, drawing #, note the equipment name and

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tag the stream is from/going to Line arrows are on each turn of a line, in the correct direction? Vessels – Size, design temperature/design pressure, full vacuum, internals/levels, skirt height to grade Heat exchangers – Area, design temp/pressure, duty, motor horsepower (air coolers), condenser/reboilers have elevation, motors have controls Heater – size, duty, design T/P, coil arrangement, utilities on a separate page Boiler – size, design T/P, superheater outlet T, utilities own page Tank – size, capacity, type, heaters/agitators shown Pump rated flow, horsepower, differential head. Showing temporary strainers, drains, motor w/ controls Turbines – in/out temp/pressure, horsepower, strainers Compressor – Actual Cubic Feet per Minute inlet, discharge pressure, driver type, horsepower, strainer, lube/seal oil Instruments are right type, local/transmitted, control type, block/bypass valves shown Instrumentation signal lines are correct line type, local/DCS code correct Control valve type, failure mode shown, block/bypass valves,

GE200 Course Handout – P&ID Designer’s Checklist

Detailed Engineering Drawings, Codes and Standards 20

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reducers, the sizes used are the latest from controls department Pressure Relief Valves: set pressure, PSV size is latest, inlet/discharge size and pipe spec. match latest calculations, outlet lines are Car Sealed Open or have no valves (if to

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atmosphere), the relief outlet goes to drain/flare/atmosphere Lines connecting to a main flare line connect to that line from above, even making a detour if necessary. (This is an old drafter’s trick to remind pipers that flare lines need to slope

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downward to drain properly) Block valves: show if they are normally open or closed, car sealed open or closed? Drain valves present, use smaller gate valve symbol, they are between checks/gates/etc. Minor valves are placed logically (check valve near pump discharge, swing blind near a gate valve) Spectacle blinds are correctly shown normally open/closed and they are on the side of the valve facing the “danger” (i.e. pressure source, contamination source) Steam-outs/steam connections where required? Full vacuum rating on equipment when required Pipe specs. are all shown and are correct, spec. breaks over valves/PSVs, steam and electrical tracing is shown Double-block valves (with 3/4″ drain between) where procedures say there are needed (normally 600 psig+ or dangerous fluids like acid) Insulation is shown on equipment and pipes? Tie Points are at all old/new line interfaces Lines connect to each other according to project’s branch table (e.g. do I need to show an expander before tee?) Show slopes, elevations, Note whenever any items must be within sight of each other (e.g. ensure level gauge can be seen by someone operating this manual globe valve) Utility P&IDs tie in correctly to main drawings, and show connect to utility stations & analyzers Header line numbers include all header block valves (so that when the header is built the block valves are installed with the header, not any branch lines) Any items rotated for easy access, such as handwheels on valves, are rotated to an angle that is possible considering the

GE200 Course Handout – P&ID Designer’s Checklist

Detailed Engineering Drawings, Codes and Standards number of bolt holes on the lines. (Ex: per ASME B16.5 I see that for 150# carbon steel, 0.5″ to 3″ lines can rotated 90 degrees , 4″ to 8″ lines can rotate 45 degrees , 10″ to 14″ can 37 38

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rotate 30 degrees) Neat DWG, no dog-legs/bad-connections When lines cross, vertical lines break for horizontal lines except that instrumentation lines break for process lines. (This rule varies by company) Matches Process Flow Diagram (PFD) connectivity, Equipment names match other documents like the PFD, equipment list, datasheet, etc. All Notes/Holds are ok? Is it clear what they refer to? Spelling? Are the general project notes and holds, that must be added to each drawing, in place? All the mark-ups were applied by the drafters correctly, spelling is correct Check the drafting process did not introduce any random new errors or mistakes. (Sometimes during a revision, a drafter’s template will be set wrong, or a line type will change for no apparent reason, causing a little mistake. And no one will be looking for it, because everyone just focuses on the areas that

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were marked up!) Are revision triangles, clouds, and other markings in the revision process added or deleted as required? Do your own mini-HAZOP of the process: can any deviation in normal temperature, pressure, flowrate, operator mistakes, utility failures, etc. cause a safety problem? Are any remaining

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safety issues going to be properly documented for the operators Similarly, can you think of any operability problems? Any common maintenance tasks that cannot be done here? Or any practical problems building or installing what you’ve planned? Taking a look at the set of P&IDs as a whole, the stream connections between the drawings are correct (all inlet streams match to outlet streams somewhere, or at least has an adequate explanation)

GE200 Course Handout – P&ID Designer’s Checklist