Differential Pressure Sensor in Water Pipe

I would like to know how to program the Arduino to work with a differential pressure sensor for measurement in a water pipe . Can anybody help me?

First, pick a sensor that meets your needs, then post a link to the data sheet, along with an explanation of your project.

Try to find a pressure sensor that is designed for use with water, that will help a lot(!)
Is this differential w.r.t. air pressure or to another water pipe?