A little help. I want to calculate the volumetric flow rate (SCFM (standard cubic feet per minute) of a pipe knowing the pressure inside the pipe as well as the diameter of the pipe. I know Where v is velocity and A cross sectional area. However, I need help finding out my velocity from my known pressure. I also know that water is the media that is being used inside the pipe. Can I relate the velocity back to the pressure via density? Any help please.