Revit MEP

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Registered: ‎03-09-2011
Post 1 of 6

suggestions for piping

688 Views, 5 Replies
06-08-2012 09:42 AM



We have a 10 story building project. Floors 2 to 9 are typical. The architects modeled in

2d fixtures with no connectors.


This is our second real revit project. We still use Revit as a drafting tool for now.


We copied monitor the fixtures but did not map it to one of ours. So we have dumb

2d fixtures in out model. We just run water & sanitary pipes close to it & stop.


The workflow in or office is to layout the pipes (pipe sizes not important yet).

Then draw the riser diagrams, size it then go back to model change pipes sizes accordingly.


The problem now is that changing the pipe sizes is too slow. It takes about a 1.10 minutes

 just to change one pipe.


We tried..

1. Stop copy monitor of plumbing fixturtes.

2. Got rid of over modeled families.


Help..We need suggestions.

*Expert Elite*
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Post 2 of 6

Re: suggestions for piping

06-08-2012 10:53 AM in reply to: Paul-s

What you've done sounds right if you only have 2d fixtures and aren't worried about creating complete piping systems. I don't know why it would take over a minute to chage a pipe size though, are your views split up by level? You could try turning off calculations through the System Browser - right-click on each of your Piping Systems, and go to Type Properties and change Calculations to None.

Valued Mentor
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Post 3 of 6

Re: suggestions for piping

06-08-2012 11:00 AM in reply to: Paul-s

Try the following

  • I'm assuming form your description that you linked the Arch model into your plumbing model and are not working directly in a copy of the Arch model. Have you cleaned up the Arch model to remove broken links, etc.?
  • Are you modelling in Fine detail and do you have loads of shaded views/fine detail views in the model. If so make them medium or coarse where possible and also turn hidden line ones into wireframe where hidden line is not essential.
  • Do not use shadows at all unless you are doing a one off rendered image. If so remember to turn shadows off again.
  • Remove any CAD imports - just link them in and make sure the links are still live. Do not explode CAD drawings into Revit unless essential.
  • Check the warnings in your model and remove as many as possible.Build proper systems in the old fashioned way - not the new "anything can be a system way". By this I mean convert an end cap from a pipe fitting to a Plumbing fixture category and set the connector's flow.

Sanitary - Preset, Out, Fixture Units, with a pressure loss

Cold Water - Preset, In, Fixture units, with a pressure loss

Then do the same a connector at the bottom of the drainage stack set as Calculated, In, etc.and set the category as Mechanical Equipment

Then build a system starting with one toilet, adding the others through the system editor and setting the connector at the base as the system's Mechanical Equipment.

If you are not using the calculations you can turn that option off in the pipe systems (assuming you're using 2012).

Same process for water but the water fittings go back to a pump probably.


  • Scrap the copy/monitored 2D elements and use the connectors described above but with 2D linework so that in plan, the show correctly symbolically.
  • Possibly split sanitary and water services into two models as piping can be slow. Link the models into each other so you can still co-ordinate.

Are you able to put a 3D DWF of your model so far on the board to see how big your plumbing model is?

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Post 4 of 6

Re: suggestions for piping

06-09-2012 07:44 AM in reply to: julianjameson8403


I already have my plumbing pipe systems not to calculate. But the mechanical pipes are set to calculate.



Yes is my answer to most of your questions. On our next project I will make sure I will refer back to this thread for pointers. We want to use Revit what it was meant for.


More things I tried doing...

1. Worksharing Update Frequency....update manually

2. a. I isolated the pipe worksets in model's 3D view.   

    b. Created a group.   

    c. Saved group to a revit file. Open created revit file. Pipes are okay when changed.

        Cleaned it up (took a long time). Copy to clipboard.   

   d. Erased all the pipes in model's 3D view.

   e. purged unused (I read somewhere this is not a good idea). 

   f. Paste from clipboard to my revit model....Same thing again. Pipe changes takes forever!

3. Began a new project. Copy/paste pipes from 3D View...Still slow!



If I move, copy, or erase a pipe. It would would take forever. However if I just copy a piece of pipe & change the size. It's okay.


I "Tab" to see how well connected my pipes are and they are 95% connected. I change the size of the pipes not connected and they change fast. It's the pipes that are connected that are giving me problems.

So I think it has something to do with my connected pipes.  


Any Ideas?



One thing more. I remember having no problems a couple of days ago. The only thing significant thing I did was used the "space naming utility".

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Post 5 of 6

Re: suggestions for piping

06-10-2012 07:24 PM in reply to: Paul-s

I have an i7 processor with 8 gigs of ram. The more pipe I connected the slower the process got. But it never got as slow as yours. I did do a fire sprinkler job where it got down to 50 seconds per connection towards the end.


I have done a couple high rises. The last one was with AutoCAD back grounds and no Arch. Revit model. I found the easiest way for me to do it was to model one floor completely (i.e.. Revit plumbing fixtures all connected with riser stubs and giving me fixture units throughout) then copy it to the other floors. Then connect the risers. Then size the risers. It went much faster. I did not create any systems as time was short. However I did let Revit compute pipe sizes (waste FU, hot & cold water FU). Also when doing waste and vent systems make sure the vent system is separated from the waste and plug the waste at the vent connection other wise the waste won't calculate. Revit does not yet calculate plumbing vent systems (I have not yet tried Revit MEP 2013).


Everything must be connected for the sizing to work except for the end of the line where the sewer leaves the building and where the water comes into the building. I also did hot water hydronics and calculated pipe sizes back to the boiler but had to disconnect the pipes at the boiler for the calcs to work.

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Post 6 of 6

Re: suggestions for piping

06-11-2012 07:53 AM in reply to: TonyVav

Tonyvav....Thank you for inout. I will also keep this is mind.


Here is an update..

I deleted all fixtures & equipments that had both water & sanitary connections.

Still slow.


I deleted all the sanitary main lines in underslab level.



Project goes out next week for bid. I dont have time to check each riser.

Is there a filter that I can create that shows pipes that intersect?

Pipes that intersect but has on "union" fitting.

How about a filter that has two different pipe systms or types in the same run?


Any suggestion?



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