# Pressure in pipe and find leakage

1. Dec 7, 2012

### darren000

I am working on a problem with 2 pipes, one 100mm and one 150mm in diameter. The shape of the pipeline is a square. half is 100mm pipe and the other half is 150mm pipe.

1.If entire pipeline is filled with water, no leak and no supply, is pressure the same through out the pipeline?

2. If no supply, and there is a leak point on the 100mm pipe at a rate of 1 L/min. what formula should I use to calculate the pressure difference?

2. Dec 10, 2012

### WillemBouwer

if you could be more clear on how the pipeline looks I think I could be able to help but I do not know what the pipeline looks like at all...

3. Dec 10, 2012

### darren000

The pipe network is attached. As you can see, water comes in from supply and goes out to E if all other outlet are shut off.

1. My first approach is to find Leak 1 and Leak 3 by closing A and C. Then flow rate in - flow rate out = flow rate leak. Is my though correct? I assumed leak 1 and leak 3 are minor leaks.

2. Known Leak 3 and Leak 1, I will close B and open A,C,D and assume no other leaks exist. Then I can measure leaks on the left side of A if they are opened.

Please let me know if I'm on the right track or not.
Thanks You. Appreciated.

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4. Dec 11, 2012

### WillemBouwer

If there is no leak and no flow the pressure will be the same, if there is flow theoretically the pressure in the 150mm pipe will be larger but the speed in the 100mm pipe wil be more. If it is a long pipeline the friction will account for some pressure losses if there is flow, which can be calculated using the Hazen-Williams equation.
Yes that thought process will be correct for that specific piece of the pipeline... However, if you open A and B simultaneously what will the flow in both the pipelines be? Is this a real live scenario? If it is, just take a measuring bucket and let the leak flow into the bucket for one minute and see what the volume of the water is... This is the most accurate approach you can have...

5. Dec 11, 2012