Hi Mohd, Normally we could ...

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Hi Mohd,

Normally we could use the simple Q = VxA, however for this to be used we need 2 known parameters.

Just a couple of questions for you:

1. What type of pipe material it it?

2. What is the distance from the source to the outlet (where you have 40m3/hr)

3. What is the static head (fall or lift) between the source and outlet; or, what is the source pressure if pumped?

4. What is the residual pressure?

 

We may be able to estimate the pipe diameter and velocity if we have a little more information?

 

We can work out what pressure drop/increase there is between the source and outlet, and divide this by the distance, it would at least provide some indication of pipe size and also velocity (hopefully you know the pipe material, which will help further).

 

Hope you can provide some further info and we can look into it.

 

Paul.

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Hi paul,

Thanks for your help

There is lots of parameters required to design a pipe, I hadn't thought about that.

I can give you only some parameters.

1.Material:mild steel

2.Water is being pumped up to to 6 m hieght through a 7  meter long pipe.

3.Pump type( filter feed pump). Centrifugal.

4.4.It a industrial wastwater treatment plant.

5.Rest of the parameters you can consider.

And please share with me the procedure of doing all calculation.

Thanks again

Regards

MOHD ARSHAD

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Hi Mohd, so sorry about the late reply, i didn't realise you had replied to my answer.

 

I can tell you that in irrigation (PVC) mainlines we use a maximum velocity of 1.5m/s. This is for two main reasons: 1. To reduce the risk of water hammer, and 2. To reduce any excessive friction loss in the pipe (because of increased pumping cost).

In steel pipework however, I  go up to a maximum of 2.2m/s because the pipe is generally going to handle any water hammer issues better than PVC.

Unfortunately, with your system we don't have any pressures (pump/pipe discharge) to work with so I can't really give you an estimate of size. If we knew the pressure differences between the pump and the discharge then we could calculate the headloss through the length of pipe and find a size.

Obviously there would be a drop of 60kPa (if a static lift of 6.0m) because of the height, but this isn't anything to do with friction. I'm sorry that I can't be of any more help to you Mohd.

Paul.

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