Revit does not auto select the proper fitting for Bends (45 vs 90) and for Branches (Combo vs wye)

[fawzimasri7137]

Hi,

i am using Charlotte pipe fittings for waste pipe.  I have downloaded their fitting families from their website.

I am having an issue with how Revit decides on which fitting it chooses to do an auto route.

1 - In Bends, it chooses a Quarter Bend (90 degrees) and places it in my 45 degrees run, instead of choosing the Eighth Bend (45 degrees).

2- In Branches, if i add a branch to main run coming in  at 45 degrees angle , it uses (tries to use) a combo (90 degrees) instead of a wye (45 degrees). 

Currently i am going around it by fiddling around with the routing preferences, but i must be missing something so i can have revit does the selection for me.

any ideas?

[iainsavage]

Sounds like a limitation of the fittings families which you are using.

Other families will either flex to suit the pipe angles or will have different nested families with an angle based formula to determine which sub-component is used.

[fawzimasri7137]

The Flexing part i understand, and i disabled it in the Bend side of things.  The reason for that, is that Revit will take a "short sweep" which only exists in the real world as a 90 degrees fitting, and will turn it into a 40 degrees, which does not exist in the real world. 

I basically forced it to stay at 90 degrees by modifying its properties and set the angle of the family to "=90 degrees". 

But now instead of Revit choosing the 45 degrees bend, it will errors out, even though that 45 degrees bend is second in priority in the routing preferences.

Is there a set of conditions or requirements i can add to the family or to routing preferences that helps Revit choose the correct fitting?

A link to document or a course on the subject is welcomed as well.. cause there is not a lot on this specific subject out there.

[iainsavage]

There are people better at this than me but usually there would be a formula something like if(Angle1<60, 45, 90).

You can also set specific angles in Mechanical Settings > Pipes > Angles so that pipes can only be modelled at 45 or 90 degrees.

@robert.klempau , @L.Maas  or @fabiosato would maybe be able to give a more complete answer

[fawzimasri7137]

yes please chime in...... i think i tackled everything i could think of in Mechanical preferences, in Routing preferences and in the Family properties of what angles to support and to constraint the family connector to those Angles in properties.

But i still can't get it to work, I must be missing some info on how it all ties together, cause i can't even explain to myself what steps/ques revit uses to decide on what fitting to choose from the routing preferences.

[iainsavage]

This page might help

https://forums.autodesk.com/t5/revit-mep-forum/is-there-a-way-to-add-specific-angles-in-the-mep-sett...

[fawzimasri7137]

Thanks @iainsavage  but still no dice... hope some of the other guys you mentioned respond to this.

[hmunsell]

Are you trying to use the Add Row option in the Routing preferences? 

personally, I have never gotten this to work right for ducts. it always picks the top option. There is very little information on it out there too. I have always chalked it up to a programing left over form Pipe Routing Preferences, where it works well. 

Even in the Autodesk Knowledge Base, "Add Row" is only talked about under the piping category (not Duct).

https://help.autodesk.com/view/RVT/2020/ENU/?guid=GUID-30A4F758-791B-41F6-9913-B4B9F52D028D

https://help.autodesk.com/view/RVT/2020/ENU/?guid=GUID-6CCBC8BF-CB33-4470-BD83-6A9AADE4592B

[fabiosato]

Hello,

You can´t fix the family angle, otherwise it will not flex, I suggest you to return the family as it was before your change.

Regarding to not proper angles, you will have to avoid them by setting the valid angles in the MEP settings.

[fawzimasri7137]

Hi @fabiosato et al 

But this is exactly what i am trying to avoid..
Revit is happy to take a 1/4 Bend and turn it into a 1/8th Bend. That's fine, until i get to scheduling and then i cannot tell how many of which i have... they all have the same name.

It is even worse when it comes to Tee/Combos/Wyes. It is happy to create a Wye but still calls it a sanTe or a combo, based on whatever i have as default in my piping preferences.

My Erroneous thinking was that Revit would somehow choose the next preference in line if it could not make the first to work, and thus i tried to force the issue by locking the angles. (i blame that on those, move-up and move-down arrows in the piping preferences)

So since i posted, i have been chasing this and i have learned few things from you and other contributors on this forum and others.

Would you be able to look at the list below, and correct my understanding?
So now i learned:

1. 
   Revit's Routing preferences are just there for keeping the Fittings you want for a specific pipe type in a known and relatively easily accessible area.
   2- Revit Routing preferences Does NOT have a concept of Hierarchy, as in try preference 1, if it does not work, try preference 2 and so on...
   3- To go around this we have 2 General Methods:
   1. Simplest, but most cumbersome for a designer is to manually change the piping preferences just before adding the fitting.
   2. Complicated but easiest to use, is to make the family Auto Change its shape and Name. This has 2 general Methods:
      1. Nesting Families... this involves creating a Host family and then loading the the other families of interest in it, then choose the family to use based on other parameters passed thru the connector such as Angles or Sizes.
      2. Create a Sophisticated family that can Flex and Change its shape and name for scheduling...this similar to the OOTB PVC DWV "combo" fitting, that can flex into a "wye" although it does not change its name in scheduling.

I am still not knowledgeable enough to execute on the last 2 points... something i am already researching....so any pointers will be great.

Thanks

[hmunsell]

if the reason your looking to do this is to itemize your fittings based on there type and angle....

• you can add an "Angle" shared parameter to the family or replace the existing Angle parameter with a shared parameter. 
  • this will allow the angle to be schedulable. 
• make a Duct Fittings schedule
• in the schedule use the Combine Parameters tool to make a parameter of the Family Type+Angle. This will put both parameters in one line (i.e. Standard-90).
• you can add what ever other parameters you want to fill out the schedule as needed.
• add the Count parameter and uncheck itemize every instance. 

You should now get a list of each Fitting sorted by Angle and how many you have. 

https://autode.sk/3hPJAKj

in my example, if you see something like the 65deg elbow and want to find it to correct it. All you have to do it select it in the schedule and pick Highlight in Model. Revit will take you right to it :-).

[fawzimasri7137]

thanks @hmunsell adding the angle was one thing i was wanting to learn in case, my flow was too involved for me to pull off.  so i will definitely study your link.

But it is important to me to also know how Revit work, so do you think my flow chart above is true to what Revit does?

[hmunsell]

Id be interested in @fabiosato take on it too, @fabiosato has a lot of good insights on stuff :-).  but here is my opinion :-).

My opinion on 1 & 2…

• it depends if your talking Pipe or Duct.
  • Adding multiple option in each category in the routing preferences for Duct, in my experience doesn't work.
  • The routing preferences works quite well for Pipe though. You can add different fittings and assign them based on the pipe size being used.
  • It is my experience that is it not meant for options, i.e. I want a 45 vs a 90. I don’t believe either pipe or duct will with a hierarchy like that.

My opinion on 3.1

•  I don’t know anyone that would waste the time doing that 😊

My opinion on 3.2

• Good luck with either one of those LOL. There is no way I know of that Revit will pick a family based on the angle you draw. And there is no way I know of to build into a family to change types based on how you draw.

---

---

Now... that said... 😁

You did say though that “Revit is happy to take a 1/4 Bend and turn it into a 1/8th Bend. That's fine, until i get to scheduling and then i cannot tell how many of which i have... they all have the same name.” This is where my suggestion for a scheduling solution came in. if your primary reason for wanting to know how may of what fittings you have, the schedule option will get you that information.

[iainsavage]

re 3.2.2 you could look at part 5 of this post, this fitting does what you want I think and you should be able to re-create the method in your own fitting.

[fawzimasri7137]

@hmunsell   all good points... it is a pipe not a duct... so maybe there is still hope.... hopefully i get more response on this.

And yes, i think sharing the Angle may be a quick solution, but looking at Wavin product from another post that fabiosato dealt with, and now @iainsavage suggests another post on it, i feel i am getting too close to solve it.... but i fear, in the end, it will end up being schedule acrobatics to get it right 🙂

I am downloading the original wavin parts now to take a look at it and compare with the ones from the other posts.

Thanks,

[fawzimasri7137]

I guess, my post is now blahhhh...
so here is my closing points:

@hmunsell  Shared parameter:
pros:
- was easy to implement, thanks
Cons:
- I need to preserve the actual dimensions of the fitting that is supposed to be used. With this method, i am not guaranteed that the Flexed sanTee will have the actual dimensions of Wye.
- I have to open each of the involved families and manipulate it. I 'd rather not have to do that

@iainsavage
The family i use now can flex a wye into a combo- like the link you showed me. And I was able to add an equation to use the angle and report an actual name of the fitting used in a shared parameter. But like i said, the resultant fitting does not have actual of-the-shelf fitting dimensions.

So for now, i left my wye as my preferred fitting in my routing preferences and after it is drawn i am replacing it with a combo if needed. I know ... not a solution solution, but it is not long term .

Thank you all for your help .

[iainsavage]

Glad you’ve got something that works for you.

I find drainage particularly frustrating due the variety of different branches and bends that can be used in a system, or even in one short run of pipe, and I’m constantly swapping fittings or moving fittings up and down the list in routing preferences. I, like you, thought I was doing it wrong but so far I haven’t found a better solution.

The Wavin fittings though are excellent, as are their video tutorials on how to use their BIM content.

[fawzimasri7137]

frustrating is the word !!!

After all this work, now i find out, that i don't have a good solution for  rolling offset...I think the OOTB PVC-DWV does it, but not my Charlotte CI library... i wish wavin, had CI-NH, i could only find PVC type... in any case, we'll see what i find out.

oh, i find this guy's video very informative, it is old, but it had all the tricks that i should have known 2 years ago 🙂

https://www.youtube.com/watch?v=PgLjwaEZ0Gk&t=911s

he talks about Rolling Offset on 21:44.  But like i said, i think now some fitting does it with the "Change Slope" button selected..

[iainsavage]

To do a rolling offset the methods I use are:-

1. Draw one pipe. Then separately draw the second parallel pipe at a different elevation then draw pipe from one connector to the other with the Change Slope and Inherit Elevation options set. Or

2. as above but draw placeholder pipes and then convert placeholders or

3. draw the two parallel pipes, select them both and then use Routing Solutions to try to work out how they should be connected, working through the options until you get the one that you want.

If you’re modelling sloping pipe you also probably want to make sure that the fittings are set to accept slope adjustments (surprisingly many drainage fittings don’t have this option set). You need to edit family, select connectors, change to Global, check the Allow Slope Adjustment option, change the classification back to Fitting and reload into project.

PS: I’m not suggesting plagiarism but I would have thought that using the Wavin fittings as a guide you could recreate the fittings that you need by adjusting geometry, materials and nested families? 

[a_kralkay]

"Revit's Routing preferences are just there for keeping the Fittings you want for a specific pipe type in a known and relatively easily accessible area.
2- Revit Routing preferences Does NOT have a concept of Hierarchy, as in try preference 1, if it does not work, try preference 2 and so on..."

I think the frustration and confusion is that it kind of does have a hierarchy, it was just poorly implemented... It obviously prioritizes the top fitting in the list. Hence the option to change the order by moving fitting up or down on that list. But that's where they stopped.

What should have happened (otherwise why even have an editable list that prioritizes the first option?) is like you mention... Try preference 1, if it does not work, try preference 2. Even restricting the type of fitting by angle (in addition to pipe size) would work. But they clearly forgot to add that code. I can't think of any reason why you would not want that to happen. I mean, we all seem to be doing that manually anyway. It's very clearly the most intuitive approach as most of us automatically assumed that's how it worked.