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Liquid velocity

Liquid velocity

Liquid velocity

(OP)
Which code or standard provides the velocity rates for liquids in piping or a pipeline.

RE: Liquid velocity

I assume you mean "maximum velocities"? In which case none AFAIK. There are plenty of guidelines and company standards floating around and a quick search on this sight will show the range of opinions on that one.

lots of people mis quote API RP 14E, which needs to be used with (great) caution.

If you mean something else then please be a bit more specific in your question.

Anything more than 5-7 m/sec is unusual as it normally just generates too much pressure drop, but it all depends on your process, fluid, degree of use etc etc.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Liquid velocity

It depends. If you type just a couple keywords of what you are looking for with regard to piping "velocity in the "search" feature of "all" forums, you will get links to boocoos of past discussions of same -- lots of nuances!

RE: Liquid velocity

Reasonable pipe velocities depend on the application. There is no correct velocity for all applications. Here is a general guideline.

Reasonable Velocities for the Flow of Water through Pipe (from Cranes Technical Paper 410):

Boiler Feed.............8 to 15 ft/sec
Pump Suction ............4 to 7 ft/sec
General Service.........4 to 10 ft/sec
City.......................to 7 ft/sec
Transmission Pipelines...3 to 5 ft/sec

Go to a basic hydraulics book. Try Cranes Technical Paper 410 as a reference for the above velocities.

http://www.eng-tips.com/viewthread.cfm?qid=111206


http://www.amazon.com/Fluids-Through-Valves-Fittin...

RE: Liquid velocity

Do a search. Velocities are determined based on economics. For clean fluids, this is a balance between the cost of pipe (procurement, fabrication) versus the cost of pump energy. For slurries, acid etc., there are practical maximum velocities associated with materials durability which may be well below these "economic" numbers. For most piping, the only harm you do by running velocities higher than economic is to waste pump energy- the notion that the upper limits are set by erosion is, in most cases, just plain wrong.

RE: Liquid velocity

I agree with bimr...... There are only suggested guidelines with acceptable velocity ranges.

There is no "piping code requirements" as is so often requested by newbies on these for a....

The most authoritative source for this velocity information is "The Piping Handbook" by Nayyar. An entire chapter is devoted to this topic. The information contained within the handbook is identical to that proposed by the ancient, but venerable Crane TP #410.

It should be noted that both guidelines also contain suggested velocity ranges for saturated and superheated steam piping velocities.

MJCronin
Sr. Process Engineer

RE: Liquid velocity

Do you have corrosion inhibitor injection into this line ? - if so, there are max velocity limits for these too-ask the CI vendor or your Company may have guidelines for these also.
If you are using some types of Cu alloy piping, there are lower limits also.

RE: Liquid velocity

You should also be aware that there are quite different concerns for "piping" and "pipelines".

For piping, noise, risk of deposition and erosion may be the main concerns, whereas for pipeline, dP, flow regime and perhaps erosion may be the main concerns.

Best regards, Mortebn

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