Pump Capacity

So easy when you think about it.

You need a pump that can deliver 1500 m3/hr over a static head of 35 m.

Now there is a nice graphic to take to the pump vendor.

Prepare for the question what your pipe work looks like.

Because this is something that you need to know before you take that pump.

So I guess back to the drawing board.

Good luck!

Mr Smith,

Thanks for the quick reply.......

I am trying to reach some pump suppliers but due to weekend I cant find one till now. Will let you know when I solved my problem. TC

What will you tell them for total pump head? Giving them just discharge static will get you some raised eyebrows.

Plus pipe losses, which in the absence of data cannot be calculated, but in typical cases might equate to something like 3-5 meters of head.

Who is this "Ghandi" person who keeps being quoted here? It's Gandhi, not that the illiterati would ever care.

Have you talked to any pump manufacturers?

Sounds like homework. You can see the flow as well as we can.

Why do you want to know the static head? You need the total head to specify the pump duty. Also the sketch only shows the discharge static. How about the suction?

Depending on the details at discharge end you might get some syphonic assistance, meaning static measured to the level of the pipe end, not the highest point.

Mr, I got your point and I can find out the static head.....but to calculate the pump capacity first i need to know the friction in the pipe so that it can supply 1500m3/h. from the discharge and velocity I can find the line size. let me know how to find friction in the pipe and from that how to calculate my pump capacity.

Your textbooks will reveal the way to solve this problem.

We will/can help with homework, but we won't just fork over the answers .

Sorry.

Yes, you do, why didn't you say that in the first place?

Calculating friction loss isn't too difficult if you know what you're doing, but it's not something we can tell you on a forum like this. Well, I can't anyway. You need to put the effort in and learn.

Just one hint - the first pipe size you try may not be optimum in terms of total costs, capex and opex, and you'll need to use judgement.

You will need an extra large pipe.

A large pipe will not suffice, in this case.

It would be foolish to even consider a medium sized pipe.

Of course, viscosity and specific gravity may dictate..............Oh never mind. You already know this.

And, if you are in the knee of the pump curve, all is well.

That's on page 42 of the text book.

Google "Hazen-Williams".

Read dimensionless numbers like Reynolds number, pretty sure how to find friction losses on pipes. Or go to a manufacturing specs of pipes and fittings, they have this rule of the thumb tables where you could get a factor/diameter x length and k on bending/fittings.

How to Calculate Static Head and Pump Capacity - 9 Easy Steps (with Pictures)

You haven't specified yet how far the water source is above or below the pump, nor the last two lengths of pipe before discharging into the tank. Wild guess 600 mm pipe (might get away with 450), 210 kW pump, but better info is needed.

If this is not a submersible pump, it lacks suction head.

Total Head Required is like = Static Head+ Friction losses (pipe+bends)

http://www.rainforrent.com/HighHeadPumps-HH300c.aspx

Be Honest.. this is homework.. right?

You googled this site, so let your fingers do the walking and google the answers.

Hint.. look for TDH.. Total Dynamic Head..

if you have problems with what you find or do not understand, then come back.

But I like many others will not just hand the answers over for you....

You beat me to the TDH!

Good answer!

you gotta get up early to beat a Welshman!! Thanks for the GA!!

A couple of points

80% overall efficiency (pump and motor) is rather optimistic, even for a biggish duty like this. 80% would be a generous assumption for pump only, IMHO, as it's likely to be a centrifugal pump. Axial-flow pumps can have higher efficiency, but the head is a bit high for axial flow. And in practice unlikely to be working at best efficiency point.

In any case motor efficiency is not needed to calculate required motor power. The rated power of a motor is the shaft output power. The electrical input power is higher.

Dear Sir,

Thank you very much for the clear Calculation you have shown.Till now I am not clear how to solve such kind of problems.

I will be in touch with you .........

May I suggest you get a copy of Crane Technical Paper 410? It will explain everything in detail. Supplement it with Flo-Serve Corp pump handbook and you will have all the technical resources you need to calculate what you ask. Then you will be prepared to talk to a manufacturer to select the proper pump. Those two books will tell you how to estimate pipe size and iterate the calculation until you have a workable system.

Also recommended is a copy of "Cameron Hydraulic Data".

Since we're here, "Crane Technical Paper 410".

I mentioned TP 410 already, but I second the Cameron handbook.....excellent resource I forgot to mention.

The Pump supplier to help size the pump for 1500 m3/hr at 40 m~45 m head.

Check out KSB Pumps to help you out.

Your line size works out as 600mm with a capacity to pass 1600 m3/hr at a velocity 1.6M/s. (ideal velocity is 1.5 M/s ~ 3.0 m/s).

http://www.ksb.com/linkableblob/ksb-en/1549040-408445/data/Selecting-Centrifugal-Pumps-data.pdf
Download this Pdf.Read page 27 : It shows that a size inlet 125mm x outlet 200 mm can pass 600 m3/hr at 40 m ~45m head. You can install 2 sets or ask KSB for a 1500 m3/hr x 1 set.If you install 1 pump you have to add 1 pump as standby.If you opt for 2 x 600 m3/hr then add 2 more pumps.(However you will get 1300 m3/hr instead 1500 m3/hr).Your pump outlet to be enlarged from 200 mm x 600 mm to match the pipe size.Do not worry about the straight running length 175m they hardly give a frictional loss of total 0.6 psi. I have added the frictional losses as 5 m for safe side.