Pump Size

What r you trying to do? Application? Makes a defference!

To select a pump you need the duty point (flow,working head) and any restrictions placed on the selection (speed, power, suction height, etc).

It is not clear what your intentions are, a bit of clarification may help.

In most cases with limited knowledge available it might be best to start at a manufacturer (or authorised distributor), The usually have detailed and selection pump curves and all other information needed. It is then as easy as reading it off a page.

for choosing the pump size,

you must know what is the shut off pressure,NPSH required,material you are going to handle and their properties like temperature, corrosiveness nature, density and viscosity, and mainly flow rate.

Let's start simple. Working head (that Hendrik mentioned in post #2), is also refered to as Feet of Head. This is simply the distance in feet, from the pump, to the highest point in the piping. Using that as a guideline, how many GPM/CFM/... will be needed to to supply required flow?

If you know how "high" the pump has to lift the "fluid", and you know how much flow you need, then the pump manufacturer can size the pump.

This is assuming that you are talking about a centrifugal pump; pumping something close to the viscosity (density/"thickness") of water. If you are talking about a positive displacement pump, pumping pulp stock, then there are other things to consider.

You will need to be more specific; if you want more help.

What's the fluid -

• Strawbetty jam?
• Blood?
• Sewage?
• Liquid sodium?
• China clay slurry?
• Toothpaste?

what for? :

pressure

estimated flow

"fluid" to be pumped

where? (environmental conditions)

which type (if you already made a choice) ?

and evrything you can say about the application and then a correct suggestion can be made.

If you are talking about an (oil) hydraulic system, you need to start with the end user (cylinder or motor) and work back to the pump.

The pump does not provide the pressure (the system does that), it only provides the flow (by virtue of displacement) therefore the static head becomes a (small and largely irrelevant) component of the system.

Anyway, tell us more (as all the other learned people have said) and perhaps we can be of real help to you.

Remember: an answer is only as good as the question posed!

Another thread with no useful info to make helping easier......!

That's the wrong size pump Andy could you please try another one. Or is that being facetious.

Is this big enough??

No, no NO!

He was after a SAE 2 bolt 'B' flange pump with Ø 1.25" parallel shaft.

I think yours is the size larger and it's got a taper shaft!

He may get back to us and confirm this. Then again.........!

Oh drat!!!

My most sincere apologies, I didn't really mean to over design the pump.

What the hell, it won't be overloaded.

And I think your pump is a (water) motor with a generator stuffed on the end!

Mind you, with the info' we have to work with, it might still be ok! He could run it backwards, then it would be a pump!

Ah ha! Eureka....... I have found it!!!

Hydro electric power. Don't tell anyone our little secret.........we will be rich.

Don't tell anyone our little secret.........we will be rich.

Thank God for that! I'm 'brasic lint' at the moment!

We could try our little plan down in Tassie and when we have finished with the water send up here to the land of the crow eaters.

I wish I had the power to delete threads like this one. Mental laziness is defined as: "How to select pump size reply with formulas" or more simply "The lack of will or, your inability to put your thoughts together in an orderly and intelligent manner."

Wangito.

i asked a ? how to calculate pump size normally for calculating the pump size flow rate is required but assume the flow and what ever the rquirement and u have to rep if u know............but dont excuse by telling mental laziness ...........i think this is suitable for u peoples

a) Please re-phrase your question. If you need help, find someone who can modify your grammar for you. It's coming over a bit blunt!

b) Please take note of all the learned contributers to this thread and SUPPLY YOUR SPECIFICATIONS OR REQUIREMENTS. Then (as if by magic) you will get relevant answers!

Please read my earlier comments again.

Now, calm down.

See, these people who are responding to you (except myself) are the most learned people in the industry and eager to help you. Tell them exactly what you are looking for and you will see that they will help you. Many of them are the people who work for the pump companies.

No need to aggravate yourself and anyone else. Just ask nicely with all the requested infromation that they asked you to give and you will have the answer in your hand quickly.

Regards;

Nadeem Butt

11122007

In asking questions, you should be more specific and polite to request the info and not order around. The words like please do not hurt any one and people open up to help. There is a world of experience at your disposal. Just tell us exactly what you are looking for and every one of us would help you the best we can.

The solution becomes very easy if you analyse the problem and unfortunately, your question does not. Also, there are text books which will tell you all about design of the pumps.

So, I would request you to please go back to your question and ask us again and this time be very specific as designing the pump is easy and pump manufacturers are big help to design with your process data.

Regards;

Nadeem Butt

11092007

3

I rply you formula

P=F/A Q=V/T HP=PQ/1714 V = VA = C(ß)= SG = C_v = Q = HP_IN = or Eff_QV= x 100

Eff_QV = Eff_VOL x Eff_MECH Eff_VOL = x 100 Eff_MEC = x 100 B₁₀ x x

The formula you need is listed above.

Tell the community what you are trying to do and we can tell you which formula and how to use it.

Recommendation: Sign up - then state your problem giving specifices as to application. Is it for home, work, school science project, etc? How much fluid is to be moved, how accurately, visconsity of fluid, etc?

sir iam an mechanical engg from india.i want to know how i can used these farmulas.

Vimal:

I am a chemical engineer from Jabalpur, MP, India.

Please use correct English when you write. Pay attention to what you write. Remember you are exposing yourself to the world and what people think that a mechanical engineer from India cannot write correct English?

Read your text books and go to the library and you will find many answers to your many questions. These people are very learned ones and will help you a lot. Just be specific in your questions. Their answers will be very precise and to the point only if they know what you are looking for and how you want to use the information.

I apologize for writing this and I hope I have not offended you in any way..

Nadeem Butt

11132007

Retain the services of a professional mechanical engineer!

from a PE

OK Guest,

Here we go.

Most pump companies have something similar to this, I am just familiar with this one.

Go to paco-pumps.com...on the very front page , on the left side, there is something called Pace Express.

Enter the desired FLOW (in GPM or what ever you want to set your units to) and HEAD (also known as pressure). Tap the Go button. This will give you choices such as motor speed, Hertz, etc. Tap the next key. This takes you to a page which gives you a list of available types of pump. Select as many different styles as you like and tap the next button. This will list all available pumps from that manufacturer initially sorted by efficiency. Select one and you will get all the pertinant information you want to know. Sorry, no formulas. Just leaving it to the experts to figure all that stuff out.

Hope this helped. Good luck. And may this thread end.......now!!!

To select a pump size, you have to calculate the power to be performed by that pump.

Hydraulic Horsepower of Pump = (GPM) (H) (S.G.) / 3960 = (GPM) (P) / 1714

where,

GPM = Liquid flow rate, gpm

H = Total head to the pumped liquid, ft

S.G. = Specific gravity of liquid

P = Total pressure drop, psi