6 replies to this topic

[sparsha]

I need help on estimating the flushing connection size. What is the criteria/guideline to follow. Is the approach/criteria same for pipelines of all sizes. I have a pipe line of 4" and another of 12" with slurry of 1% solid concentration. Is the flushing methodology same for both the pipes. I have a velocity of around 2 m/s in the pipeline with the process fluid under normal condition. What should be the velocity of the flushing water(the flushing medium i am using)? Should this be close to the velocity of process fluid. We typically have drain and utility connections of 1 to 2". How can we achieve the velocity of 1-2 m/s during flushing with 2" flushing and drain nozzle.

Any clarification on this topic is highly appreciated.

[shan]

Flushing is to use high velocity fluid to carry away the process deposit.  The flushing fluid velocities have to higher that the process stream velocities to clean the lines effectively.   

[sparsha]

Hi Shan thanks for the response. But i have a 8" pipe line with 1 wt% slurry. How can i achieve high velocity in this pipe with 2 or 3 inch flushing connection.

[shan]

The slurry solids deposit on the bottom of piping.  High velocity jet flow should be introduced to wash away deposited solids.  You should use the flow volume rate divided by jet nozzle area to obtain the jet flow velocity instead of the flow volume rate divided by 8" piping area.  The jet effect velocity will diminish to the normal piping flow velocity at a point certain distance away.  The point is the location of your next flush nozzle.

[samayaraj]

Hi Sparsha,

 

All piping systems shall be flushed using high pressure jet flushing equipment, such as rotating hose or rotating nozzle. 

 

Below 4”, High Velocity Water Flushing (HVWF) may be used. Water velocity shall be a minimum of 10m/s. On systems where high pressure jet flushing cannot be used due to complicated shapes and/or long runs HVWF may be used.

 

The flushing medium shall in general be fresh water. When flushing stainless steel lines, the chloride ion content shall be less than 200ppm.

 

Kindly refer the attached document, Pg. No. 10

 

#Samayaraj

Attached Files

•  flush.pdf   88.8KB   94 downloads

Edited by samayaraj, 11 November 2014 - 10:38 PM.

[Ajay S. Satpute]

Sparsha,

 

You may refer below article.

http://www.cheresour...on-methodology/

 

Regards.

 

Ajay S. Satpute

[sparsha]

Thanks a lot for your valuable replies