Velocity in pipe 2

[lorang]

Hello,
I'm working in a company which design and install a lot of différents fluids network.
We have internal standard to dimension pipe's diameter depending of fluid, flow rate, pipes materials, type of circuits.
Today, we want to uptodate this standard to optimise the diameter.
I've not find some datas other than we have to determine the limits of velocity.
How do you do in your industries? Have you got some references? What is the factor that impose the maximum velocity ? There is the limitation of pressure drop, but are there other factors?

thank you for our answers.

 

[Montemayor]

Lorang:

To get a free Excel spreadsheet on calculating an “optimum” pipe size, go to:

http://www.cheresources.com/software.shtml

Pipe Size Optimization for Carbon and Stainless Steel Pipes (direct link to *.xls file) will get you a workbook of what you want. This simple spreadsheet will calculate the most economical pipe diameter for a system based on flowrate, fluid density, and fluid viscosity. The sheet is to be used for turbulent flow in carbon or stainless steel pipes. It is designed to run on Excel 97 or higher and utilizes the Solver function so it must be installed as well. It refers to a published article that you can read.

Notice that the above says “economical”. You don’t state what other optimization condition you desire, so I’ll assume that’s what you meant. If you desire limits on velocity, then that’s empirical values that you’ll find across a broad spectrum of text books and articles. Is that what you want? The way I’ve handled the subject of velocity is that I depend 100% on my experience in setting the maximum mean fluid velocity. Others may depend on published data or references. I don’t trust anyone that easily without proving it myself before applying it.

I would not use fluid mean velocity as a determination for a pipe size. There is a range of velocities that can be realized with good operation. The size of the pipe is determined directly by the maximum allowable pressure drop – with a corresponding acceptable fluid velocity. The acceptable velocity is where the experience comes in. The material of the pipe, the fluid in question, the pressures involved, etc., etc. all have a role in determining what is an “acceptable” mean fluid velocity range for your application. I hope this addresses and answers your queries.

 

[rmw]

Here is a link to a site that gives conservative velocities for fluids specific to their industry. Might be a good point of comparison for you.

http://www.sugartech.co.za/piping/fluidflow.php

rmw