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3

# Split Flow Between Two Pipes At Ratio

6 replies to this topic
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### #1 Abiodun1

Abiodun1

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Posted 30 October 2023 - 07:08 AM

The attached drawing is a model of a 16” pipeline with an 8” diverter line, showing flow direction (indicated by an arrow), a flow meter, flow rates F1, F2 & F3 and flow devices S1, S2 & S3. Flow from F1 is required to go through F2 & F3 in a precise ratio according to the formula: F1 = 0.45F2 + 0.55F3.

This means that 45% of flow coming from F1 should be diverted to F2 while 55% flow through F3.

S1, S2 & S3 are devices that may help achieve this. For example, S2 allows only 45% of flow from F1 to go through or S3 allowing only 55% of F1 to go through.

Thanks.

#### Attached Files

Edited by Abiodun1, 30 October 2023 - 07:15 AM.

### #2 breizh

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Posted 30 October 2023 - 07:12 AM

Hi,

No sketch.

Breizh

### #3 Abiodun1

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Posted 30 October 2023 - 07:16 AM

Hello Breizh,

I have attached the sketch. Thanks

### #4 latexman

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Posted 30 October 2023 - 10:18 AM

Find the pressure at the junction of F1 and F2 and F3.  Call it P123.

Determine the pressure at the end of F2 and F3.  Call these P2 and P3

Then, calculate F2 and F3  with the appropriate dPs, namely P123 - P2 and P123 - P3.

### #5 Abiodun1

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Posted 30 October 2023 - 12:51 PM

Ok. Thanks

### #6 breizh

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Posted 30 October 2023 - 06:54 PM

Hi,

What are S1,S2,S3 in engineering words ? Valves?

How many flow meters in place? Only F1 or more?

What is the fluid?

I think Latexman is showing you the right direction.

Breizh

### #7 snickster

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Posted 31 October 2023 - 03:07 PM

You are splitting flow almost half and half into the 8" and 16".  Therefore the 8" which have about 4 times the pressure drop of the 16".  The flow will mostly want to go through the 16" natually with very little going to the 8".  Therefore you must force the flow to go into the 8".  If you are only concerned about a certain volume going to the 16" you could put a control valve/flow meter arangement on the 16" where S3 is shown and set the flow meter for a certain value.  The control valve will throttle to create back pressure to push flow into the 8" based on flow control from the flow meter.

If you need to maintain the 45/55 ratio for any given flow in the main line then you will need to have some kind of controls to measure the main flow upstream and have the set point of the meter/control valve arrangement at S3 vary to acheive 55% of upstream measured flow.