Lookup Table

[nej_pavliV2GEK]

HI, is it possible to have parameters so that you can change the value in my case Name and the Diameter and Radius change value. Name represents the The nominal size like DN10... Can i put in the excel DN10, so that everybody who will want to change value will know what to change.

[iainsavage]

I don't quite follow what you are trying to do here but the normal use of lookup tables is that the fitting size (nominal diameter or nominal radius) would be automatically assigned via the pipe connector (i.e. fitting size matches pipe size), then the lookup formula uses that value to extract other data such as fitting outside diameter, centre-to-end length etc.

If you want users to manually select which particular fitting they want to use then you would be better creating family types and they can select the type from a drop-down list - you can use a type catalogue for that rather than a lookup table (they are similar but different). If you use that method then in your pipe routing preferences you would need to assign a different fitting type to each size of pipe.

[nej_pavliV2GEK]

Now i change the value of Diameter and the formulas foe excel change the value of Name and Radius. But i want so that i change the value of Name and that formulas change the values of Diameter and Radius. 

Do you maybe have any links for Drop down list tutorials?

[iainsavage]

Sorry I still don't understand why you want to manually change the fittings rather than having them automatically match the pipe size.

However if that's what you want to do then you can use the family types method that I described or if you want to do it using a lookup table then you would need to add another column and duplicate your column A data into that column, then use those values as the lookup value in your formula. Column A is ignored in the lookup formula so you need that same data in another column. Not sure what sort of results you will get though - you maybe need to disassociate the diameter/radius parameter from the connectors to prevent the fitting from adopting the size from the pipe.

This is however a weird way to do piping in Revit.

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[nej_pavliV2GEK]

Its because this dimensions are from a supplier, and i need this exact sizes of pipes.

Ok, but what do i type in formula because i already tried like size_lookup(Lookup Table, "R", 10.5 mm, Name) and it says invalid input or something like that. 

[iainsavage · Accepted solution]

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@nej_pavliV2GEK wrote:

Its because this dimensions are from a supplier, and i need this exact sizes of pipes.

Use  a parameter called Nominal Diameter or something like that. Associate it with the connectors. This would then automatically be the size which you inherit from the pipe e.g. 10, 15, 20, 25 etc.

Put a column  (not column A, usually you would put in column B) in your table with these sizes. Call it ND or something similar.

Use ND as your lookup value to then drive the actual manufactured sizes of the fittings.

That will work and is more realistic in terms of real world because you would buy a 25mm ND elbow, not a 33.7mm elbow, buy a 100mm ND rather than a 114.3mm. etc.

Here's an example from an Autodesk family: