10 replies to this topic

[binzee]

Hello!

I wanted to know recomended velocities of different petroleum products through pipe, especially Kerosene.

Regards

[pasquale]

Hi

For the kerosene the maximum velocity in pipe is 3 m/s, moreover 50-100 m
upsteam a tank or a loading facility the max velocity shall be reduced to 1m/s
because of the risk of static electricity.

This is valid only for kero

Best regards

Pasquale Rome

[Art Montemayor]

All Chemical Engineering Students:

Attached is a collection of recommended fluid mean velocities through piping.

Please note that these are RECOMMENDED DESIGN values and they come from different sources that had different experiences.

Note that some of the descriptions of the type, state, condition, age, etc. of the pipe(s) and of the fluid can make a marked difference in the correct (or recommended) values. The best way to ensure accurate values is to back them up with personal experience - and that takes years of working.

There is no absolute, 100% accurate answer; you should use discretion, common sense, and good engineering judgment in picking a value. Common sense dictates that you not pick a value for clean, new pipe and expect that it will stay that way for the duration of its installation. It is more than obvious that the value will vary depending on the fluid and the pressure and thermal conditions. Try to design under a conservative basis.

I hope this helps you out.

[kumaqal.engr]

I read that recommended velocities differ for suction and discharge line beside this its depends upon the nature of the fluid handled.

For Benzol, Gas oil it's 1.0 - 2.0 meter/sec
For Heavy it's 0.5 - 2.0 meter/sec

Source: Pipe work calculation

[pasquale]

Hi Binzee,

in my reply there is not confusion beetween fps and m/s because for liquid line at pump discharge for me 5 m/s are the value that must never be superseded.

In fact the maximum velocity depends on the line's diameter and on the allowable pressure drop.

So for general process service at pump discahrge i suggest to you to use a mean velocity of 1.5-3 m/s

Pasquale

[Arancha]

Hello

I am really interested in the collection of recommended velocities but cant´discharge the spreadsheet.
I woul be very grateful if you could upload it again or send it to me by email Aranchaesp@hotmail.com
thnak you very much in advance

Arancha Espadero

[Art Montemayor]

Here it is, one more time.

 Recommended_Fluid_Velocities.xls   26.5KB   591 downloads

[JEBradley]

I have an idea what velocities I want my liquids to flow at but can someone tell me why???

I mean what's actually stopping us throwing water through a 1" line at 20 m/s??

I suppose ultimately we'll be getting dangerous mechanical stresses on the line but is there anything else.

[Art Montemayor]

JE:

The "anything else" to fluid velocity through a pipe is fluid pressure drop through the same pipe.

I personally never size piping based on velocity - despite what API 14E states. I always employ the allowable pressure drop to dictate what the resulting velocity will be - unless ordered to do otherwise. It is in this way that I can ensure that the design amount of fluid will get to where I want it to end up at.

Other than noise and vibration (in the case of compressible near-sonic flow), you have errosion to contend with when you exceed certain fluid velocities. You also have the effect of causing spontaneous decomposition in the case of certain, sensitive compounds - such as acetylene.

[nadirsha]

I can t open the excel sheet,

can you please send me by mail: nadirsalu@gmail.com

best Regards

Nadir

[engware]

Hi there:

Check out the eFunda web site at: http://www.efunda.com where one can use free online calculators and see what the pressure loss is for given fluid velocities and properties.

Thanks,

Gordan