Hi dustinSolar and welcome !
There is one library made with/for FreeCAD, it's here : https://github.com/yorikvanhavre/FreeCAD-library
But i'm pretty sure that there is'nt part like you want.
However FreeCAD can import a lot of 3d cad formats so if you found part in grabcad or other resources you can import it and deal with it.
About pluming (plumbing?) there is'nt tutorial about that but the Part_Sweep
tool will help you to projected profile along a path.