3D Pipe & Plant Layout Modeling - DOs and DON'Ts

There seems to be a lot of piping designers out there that are great at using 3D modeling software but are missing Pipe design basics. I’m trying to come up with a list of 3D modeling do’s and don’t that is not really software specific that I can pass on to junior/intermediate designers.

Here are just a few items that frustrate me:

• Modeled lines with inconsistent specs and line numbers that do not match the P&ID
• Equipment not shown in the correct elevation. Lack of coordination between Civil an Piping
• Valve hand wheels rotated at oddball angles e.g. 4” 300# gate valve hand wheel rotated 56 degrees
• Valve actuators modeled incorrectly, causing clashes later on. (even though the cuts sheets are available)
• Placing equipment in oddball coordinates /reference dims. e.g. 5’-2 1/16"

Please share your frustrations and ideas.

Here are a few more items that frustrate me:

-Modeled lines without considering the supporting requirement.
-Modeled lines/equip/instru/Nozzles with wrong naming conventions.
-Modeled lines without considering the supporting requirement.
-Modeling done with wrong NS/EW coordinates.
-Modeled lines without making everything visible on the graphical screen leading to lots of clashes with steel, equip or other facilities.
-Modeled lines with valves/instruments located inaccessible for operation/maintenance.
-Modeled lines without connection references to Nozzles/Tees etc.
-Modeled lines without considering headroom clearance requirement.
-Modeled lines with improper slopes.
-Modeled lines without showing floor penetration if applicable.
-Modeled multiple times one over the other at the same location.
-Modeled lines without considering proper support types like rest, guide, axial stop, anchor etc.

& the list continues......

Here is one that happened to me recently.
The Project Engineer comes to a model review and hands out P&ID's which don't match what the Piping Designers have been modeling to. He had the P&ID group update the P&ID's (master stick with Process group for one month previously and inaccessible to pipers) unbeknown to pipers as latest process info was on hand drawn sketches on various engineers person, not even on Master stick file. As a result the model was out of date with the P&ID's. What he should have done was wait until the model review had finished for review of previously agreed on frozen P&ID's from Hazop and then hand out the new set as an addendum to the review.
He realised his mistake later and apologised profusely to the pipers.

It is good to know that he finally apologized to the pipers & he understood his mistake.

The biggest mistake was to not have the master P&ID stick file in the piping area, so that the pipers were made aware immediately of the proposed process design changes. I'm surmising, but I'm willing to bet that this little omission has caused some design and stress rework and possible schedule delays. I'm also quite sure that not all of the changes are necessary nor approved by the project management team. At the least, if I were the piping lead, I'd be speaking with the project manager to firstly secure approvals before making any piping changes that result from these new mark-ups, and secondly to make it clear that I'll be trending all rework that affects my budgeted hours. Also, while I would do my best for it not to be the case, that I'm not going to be responsible for any schedule delays that may result from this.