What is the maximum span of a peir in a floor system

A pier is a vertical support member so it really doesn't have a "span" like you are referring to. If you neant what is the span of a horizontal floor framing member (beam or joist) it would depend on the size and type of member. Give us a little more info.

Like amricca says tell us what is setting on the peir, that will determine where the next peir should set