Using add grips provides an efficient way to quickly begin drawing a plumbing line. It ensures connectivity between the object and plumbing line.
Add grips on a plumbing line segment
Add grips on a plumbing fitting
Add grips on an MvPart (a sink)
Some fittings also contain add grips that enable you to create a new branch directly from the fitting. For example, an elbow has add grips you can use to automatically convert the elbow to a tee, from which you can then draw a plumbing line. The existing plumbing branches remain connected to the other 2 tee connections.
Add grip selected on an elbow
Plumbing run drawn from the elbow
Elbow automatically converted to a tee