Help Needed with Creating Elbow Family in Revit (New Piping Drafter)

[lupacat]

Hi everyone,
I’m a new piping drafter, and I’m currently working on creating a new pipe fitting family in Revit, following the pipe specifications from the material supplier.

I’ve already created the parameter CSV file and imported it into Revit. The units are set to millimeters, and the new family uses the Metric Generic Model. Everything seems to be going smoothly until I got stuck while entering the formula in the "Outer Diameter" dialog.

I don’t have any knowledge of Dynamo or programming in Revit, so it’s really difficult for me to create a new family in Revit.

My questions are:

1. Formula for Outer Diameter:
   I’m unsure how to input the correct formula in this dialog box. Could anyone show me the correct formula to use? Also, how many formulas do I need to input to complete this new elbow family? I would greatly appreciate it if someone could walk me through the steps, one by one.

2. Dynamic Data for Pipe Fittings:
   The pipe fittings come with a lot of dynamic data for each type. For example, the Elbow 90-degree Sch. 10S has 15 types, and the inside diameter and thickness values change based on the outer diameter. I believe it’s possible to create a new elbow family where these values update automatically, but I’m not sure how to do this.

3. Ideal Elbow Family Model:
   In my ideal model, when I select the Sch. 10S elbow in Revit, the type selector in the properties palette would allow me to choose from 15 different elbow sizes, depending on the specific requirements.

4. Attachments:
   I’ve attached the CSV file and a screenshot for reference. Any advice or guidance would be greatly appreciated! Thank you in advance!

[lupacat]

Hi iainsavage,

I have a question regarding shared parameters and type catalog. The reason I'm asking is similar to the situation with the .csv file I created. So far, I've only created an elbow for a 100mm Nominal Diameter, but as shown in the .csv file, there are 17 elbows of the same type with different values, including outer diameters, inside diamter, thickness, and so on.

I'm confused about how to proceed: do I need to create each one indivdually? Would using a family type catalog or shared parameters be helpful in this situation? I'm struggling because I don't even understand the different between the two, or how to use them correctly.

I'm asking these questions to make sure the process I'm following to create these families is correct and that everything is on the right track. I would be extremely grateful if you could explain this to me.

Thank you very much again!

[iainsavage · Accepted solution]

I'll take a look at your uploads later but meantime:-

"although visually it still appears just a tiny bit smaller than the connected pipes" This implies that your fitting outside diameter doesn't match the pipe outside diameter. Could you upload a sample project which contains your 10S pipe type please?

"such as material, standard, manufacturer, description, etc" 

These built-in parameters are contained by default in a pipe fitting family, you don't need to add them:

Material: you can apply material(s) to the parts in the family using the Revit Materials Library. You can also add a material parameter(s) to the family to store and display this information in the project

https://help.autodesk.com/view/RVT/2024/ENU/?guid=GUID-FB6FB0B3-BFFC-4884-BFB3-0369DA6AE905

Standard: You could use the built-in Assembly Code parameter or create  your own parameter

Manufacturer: There is a built-in parameter for that, see earlier screenshot of Identity Data

Description: ditto

"When creating families, what exactly does "shared parameters" mean?" Shared parameters are ones which you set up for use in multiple families and they are stored in an external text file so that you can import them into families or projects. They can be used in tags and in schedules. You can obtain ready made shared parameter files from some sources but I think you would be better developing your own company ones. Apart from the advantage of being able to use them in tags and schedules, the other advantage is consistency, for example if you wanted a parameter  for Standard and you're going to have this in every family then make it a shared parameter so that it will be the SAME parameter in all of your families and will appear as one column in your schedules. If you don't use a shared parameter for this then the Standard parameter in each family will be a DIFFERENT parameter in each family even although it has the same name.

https://help.autodesk.com/view/RVT/2024/ENU/?guid=GUID-E7D12B71-C50D-46D8-886B-8E0C2B285988

2. Do they always have to be in a .txt file, and how do I create that file?

Yes they need to be in a special text file. The file will be created when you create your first shared parameter. You DO NOT edit the file manually.

You can have more than one file if you want.

See the link above.

3. What's the difference between shared parameters and .csv file I edited?

The .csv file will be either a type catalogue or a lookup table depending on how you are setting up your family.

These tables only apply values to parameters which you have already created, they do not create new parameters.

If you create a new shared parameter, e.g. Standard, then export family types again there should be a column for that in your table.

4. How can I add the additional info. (such as material, standard, manufacturer, description, etc.) into the new elbow family?

See my earlier comments

[lupacat]

Hi  iainsavage,

Thank you very much for your guidance, sure, I attached a sample project which contains my 10S elbow type for your review.

[iainsavage · Accepted solution]

Your elbow family is not using the pipe size or lookup table to determine the external dimensions of the fitting.

You have just fixed the external diameter at 108.2mm whereas the pipe external diameter is 114.3mm.

That's why they visually appear to be different - because they are different.

As far as I can see the external diameter of a 4" (100mm NB) 10S fitting is 114.3mm, to match the pipe spec and that's what you had in your lookup table.

It looks like you've used the inside diameter value instead of the external diameter:

[edited: I had screenshot your original table, but now have the version contained in your family - but you aren't referencing it at all for ID, OD, CE (Centre-to-End) etc.]

This fitting family is only suitable for use on 100mm pipe and will not adapt to any other pipe sizes. 

You need to go back to the beginning of your post where you asked how to use the lookup table to set the fitting dimensions for different pipe sizes.

PS: the "b" dimension is used to calculate the centre-to-end length for elbows of less than ninety degrees

[sagnewYUXLR]

the help and guidance @iainsavage gives on this portal is amazing. 👌