Pipe manifold design data??

[antoil]

Hi!

Looking for how to design a pipe manifold for petroleum products.I have 1x6" inlet and 10x6" outlets,Q=200m3/h,WP 3 bar.Which is the size of the main pipe??Are there any math calculations that give us the size?
Any help would be appreciated!!

 

[StephenA]

Your question needs some explanation.

The inlet (into the manifold?) is 1No. 6" pipe

The outlets (from the manifold?) are 10No. 6" pipes

This looks strange as 1 6" pipe will feed 1 6" pipe.

Which main pipe are you referring to?

StephenA

 

[antoil]

Imagine a 3m long, X" size, pipe, blind flanged at both ends.

On the one side of this(X") pipe there is a 6" inlet nozzle branched and on the oposite side 10 nozzles ,of 6" each, followed by valves.

What is the X size of that pipe in order for us to have a normal velocity flow?

 

[StephenA]

I have answered my own question. Obviously you mean the main manifold pipe.

If you are taking off at only 1 port at a time then you have the losses through a T piece.

If the manifold is also 6" then the T piece losses will be quite high.

On the other hand if you use a 12" pipe, then there will be inlet losses (as the pipe increases in size) but lower losses into the outlet pipe.

Any fluid mechanics text book will give you the calculation of the two sets of losses.

Someone else may have a "rule of thumb" of say twice the port diameter

StephenA

 

[antoil]

Thanks a lot StephenA!

 

[mgp]

Quick rule of thumb

Tog get the same fluid velocity, the square area of the manifold should have the same square area as the sum of the outlet pipe square areas (or inlet pipes). Divide by pi/4 on both sides of the equal sign you get:

D^2=d1^2+d2^2+d3^2+........+dn^2

where:
D is the Manifold OD
n is the branch number
dn is the branch pipe OD for branch n

If not all branches are in use simultaneously, then you can include only those that will be used (worst case) but be sure then. It may be costly to increase size at a later date.

Hope this helps
Regards
Mogens