Detailed Engineering Drawings, Codes and Standards

PIPING & INSTRUMENTATION DIAGRAM – DESIGNER CHECKLIST

S/N CHECK ITEM DESCRIPTION

1 My company’s document/drawing #

2 Client document #

3 Licensor/Vendor document #

4 Title block: including the By/Approved/Checked blocks filled and

signed, Date, Rev. all company logos, client signoff block?5 All equipment tagged, title above equip, spelling of names

correct?6 Not crowded: Normally have about 4 pieces of equipment per

drawing7 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

tag the stream is from/going to8 Line arrows are on each turn of a line, in the correct direction?

9 Vessels – Size, design temperature/design pressure, full

vacuum, internals/levels, skirt height to grade10 Heat exchangers – Area, design temp/pressure, duty, motor

horsepower (air coolers), condenser/reboilers have elevation,

motors have controls11 Heater – size, duty, design T/P, coil arrangement, utilities on a

separate page12 Boiler – size, design T/P, superheater outlet T, utilities own page

13 Tank – size, capacity, type, heaters/agitators shown

14 Pump rated flow, horsepower, differential head. Showing

temporary strainers, drains, motor w/ controls15 Turbines – in/out temp/pressure, horsepower, strainers

16 Compressor – Actual Cubic Feet per Minute inlet, discharge

pressure, driver type, horsepower, strainer, lube/seal oil17 Instruments are right type, local/transmitted, control type,

block/bypass valves shown18 Instrumentation signal lines are correct line type, local/DCS

code correct19 Control valve type, failure mode shown, block/bypass valves,

GE200 CourseHandout – P&ID Designer’s Checklist

Detailed Engineering Drawings, Codes and Standards

reducers, the sizes used are the latest from controls department20 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

atmosphere), the relief outlet goes to drain/flare/atmosphere21 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

downward to drain properly)22 Block valves: show if they are normally open or closed, car

sealed open or closed?23 Drain valves present, use smaller gate valve symbol, they are

between checks/gates/etc.24 Minor valves are placed logically (check valve near pump

discharge, swing blind near a gate valve)25 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)26 Steam-outs/steam connections where required? Full vacuum

rating on equipment when required27 Pipe specs. are all shown and are correct, spec. breaks over

valves/PSVs, steam and electrical tracing is shown28 Double-block valves (with 3/4″ drain between) where

procedures say there are needed (normally 600 psig+ or

dangerous fluids like acid)29 Insulation is shown on equipment and pipes?

30 Tie Points are at all old/new line interfaces

31 Lines connect to each other according to project’s branch table

(e.g. do I need to show an expander before tee?)32 Show slopes, elevations,

33 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)34 Utility P&IDs tie in correctly to main drawings, and show

connect to utility stations & analyzers35 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)36 Any items rotated for easy access, such as handwheels on

valves, are rotated to an angle that is possible considering the

GE200 CourseHandout – 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

rotate 30 degrees)37 Neat DWG, no dog-legs/bad-connections

38 When lines cross, vertical lines break for horizontal lines except

that instrumentation lines break for process lines. (This rule

varies by company)39 Matches Process Flow Diagram (PFD) connectivity,

40 Equipment names match other documents like the PFD,

equipment list, datasheet, etc.41 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?42 All the mark-ups were applied by the drafters correctly, spelling

is correct43 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

were marked up!)44 Are revision triangles, clouds, and other markings in the revision

process added or deleted as required?45 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

safety issues going to be properly documented for the operators46 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?47 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 CourseHandout – P&ID Designer’s Checklist