Two recent Revit MEP related cases brought up some new information on the pipe
K factor table and custom calculations for pipe fittings, the Forge DevCon class recordings are now available, and I discovered Konrad Sobon's wonderful archi+lab Revit API blog, which helps resolve an installation and setup issue
K factor table
K factor calculation for pipe fittings
– Dynamo code to change loss coefficient
– Forge DevCon 2017 class recordings
– Revit add-in installer and buttons...