Is there a way to find "equivalent length" of a pipe route modelled in Revit?

[n_ahmadi93CBU]

I have pipe route modelled from point A to point B. I can obtain pipe schedule where it provides individual straight pipe lengths in the pipe route, but not the bends, traps, elbows, fittings, ext. 

I am sure there must be a way to find equivalent length of the pipe fittings but not sure how. I am specifically asking for refrigeration piping routes that have a lot of fittings, elbows, p-traps, and ext, but the only length info that i can obtain from Revit, to the best of my knowledge, is the straight pipe lengths.

Thanks, 

[iainsavage]

"Equivalent length" of a pipe fitting is not the geometric length, it is the length of straight pipe which would have the same pressure loss as the fitting - is that what you mean?

[n_ahmadi93CBU]

Right, that is what i mean

[iainsavage]

Firstly, Revit doesn't really do pressure drop calculations for refrigeration systems. It only works for domestic water and hydronic circulations systems. You can adjust fluid properties to suit fluids other than water but I don't think you could make it deal with compressible gases and phase change fluids - maybe someone else knows otherwise?

For domestic and hydronic systems you can generate a pressure loss report for the system and it will itemise pressure drops in individual pipes and individual fittings (example below).

Revit generally uses the K Coefficient method for determining losses in fittings (not to be confused with the Kv method!), rather than equivalent lengths.

Equivalent length isn't an available field in the pressure loss report as far as I can see but you could calculate it by dividing the calculated fitting pressure loss by the applicable straight pipe loss per metre/foot. You can copy/paste from the html pressure loss report to a spreadsheet and then maybe add your own calculation columns (if you can work out the formulas that you need).

Or maybe it could be done with Dynamo to extract fitting and pipe data for each section, do the calculation and send the result to custom parameters, but I wouldn't know how to do that.

You can also select a fitting in a view and see its pressure loss factors in the properties panel.

If however you are doing your own manual/tabulated calculation based on equivalent lengths then if you know what the hypothetical equivalent length of the fitting should be, from manufacturer's data or technical resources, you could add a shared parameter to each family and populate the data yourself and then that could be a column in a pipe fitting schedule in Revit. 

The problem that you face though is that you would have a schedule of pipe lengths and a separate schedule of pipe fitting equivalent lengths but no direct correlation between the two. Again maybe there's a way with Dynamo to create an association between the pipe section and the fitting(s) but again I don't how to do that.

You could possibly utilise the pressure loss report for that though, since it does contain those associations, but again it would involve post-processing the data manually or in a spreadsheet.

That at least is my take on the situation but maybe someone out there has better knowledge on the topic?