Maximum Velocity in pipelines

[BRIS]

I am told that AWWA in some publication have produced a table of maximum allowable pipeline velocities for various piper diameters. I know of no such table and I would be interested to know if anyone as come across such a table. I suspect the table is being quoted out of context.

brian

 

[mohtogh]

Here , in this site , is a lot of discussion about this matter,please seach firstly.
Also a good information is:

http://www.sugartech.co.za/piping/fluidflow.php3

hope this help

 

[mohtogh]

Ooops!
Probably the above not your answer.
Check this link, for title piping you see two formula about V vs. D

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

bye

 

[BRIS]

Thanks for the link but I am specifically looking for a table from AWWA. Our client says it exists and requires us to comply with it but he can't give us a reference and I know of no such table. I suspect that, if such a table does exist, it is related to limiting velocities in order to limit waterhammer.

(oops for 'as' read 'has' in my first post).

Brian

 

[TBP]

In the Piping Handbook by Nayyar, it lists the AWWA publications. I don't see a reference for velocity in this list, but this is the 6th edition of the Piping Handbook, and I know there is a newer version. Piping in this service isn't my area of expertise, either. I'd suggest contacting the AWWA directly. They'll either tell you what standard they have that applies, or that they don't publish one covering this issue. I suspect that they don't, since many municipal water systems have dealt with water mains that have become undersized due to increased demand, by simply jacking up the inlet water pressure to the system. The bigger pressure drop will provide more GPM, but the velocity of the water in the piping goes up with it.

 

[jmw]

TBP there is a recipe for disaster! But a popular one. It is estimated in the UK that 25% ofwater is lost from the pipes due to leaks. Old pipes, undersized and increased demand.... increasing the pressure sure does increase the flow but it also increases the potential for failure. Short of a major program of investment to replace everything, jacking up the pressure is an expedient that water rich environments can possibly afford in the short term.

 

[TBP]

We do work in industrial plants that have taken that route. (We'll just add some booster pumps...) We've told them what causes the leaks in their systems (HIGH velocity), but they won't spend the money to upgrade their water lines. In some cases, we've been back to "replace the replacement" elbow (copper) in less than 6 months. The initial installation in one plant was a very cheap & nasty one done by the low bid contractor - he didn't ream any of the type 'M' copper pipe after it was cut. This is a spectacular combination - thin unreamed copper pipe combined with big velocities, in a process plant that uses water almost continuously.

 

[CARF]

http://www.copcoltd.com/soft/freeeng05/pipez.htm

Economic Pipe Sizer

 

[Domenico]

Brian,
Have you found the AWWA table or similar?

If so, please advise where.

Thanks,
Dom

 

[BRIS]

Domenico

No - I have not found the table.

brian