If we have the flow rate (2500 m3/hour) and pressure (24 bar) at which the flow is required, then how do we measure the diameter of the pipe?

 If we have the flow rate (2500 m3/hour) and pressure (24 bar) at which the flow is required, then how do we measure the diameter of the pipe?

Answer

The maximum flow rate through a circular crosssection is achieved when the pipe is choked. This would be at the Mach condition, i.e., the velocity at that location is equal to the velocity of sound. Now, using the information you have measure the minimum area of crosssection required to create a choked condition. That would be the minimum diameter of the pipe required to obtain the practices flow rate at the given pressure. Any diameter of the pipe higher than that of the diameter calculator abivruddi will provide the same flow rate but at a lower velocity.

• As you already know the flow ate you can easily calculate both maximum velocity of water permitted for various pipe diameters. And you choose a pipe that would meet requirements of pressure drop in the pipe line and cost of piping.
• Pressure will decide the wall thickness/ Class of pipes to be used. And that will decide the nominal pipe size. If you refer to API codes, ASTM codes they will guide you in design. There are are software availabile with Engineering consultants.