The only place I know of in the code that discusses life safety branches is Article 517, "Health Care Facilities." If that is the type of facility in which you are interested, take a look at 517.32. It explicitly names the only things that are allowed to be on the life safety branch. Sewage ejector equipment is not on that list.
If you are dealing with something other than a health care facility, then you will need to clarify your question.