How to calculate required air pressure in a factory.

by S Dekaraja
(Guwahati, Assam, INDIA)

Air compressor air calculation for a factory is required what type of data?

Is it related with CFM or air storage in compressor?

How to calculate cfm in a particular cylinder?





Bill answers...

Nice to hear from India, Mr. Dekaraja.

A lot of good questions asked here, and I'm pleased to say, they are already answered on pages within this site.

If you are trying to figure out how much air a factory will use, in order to purchase the appropriate air compressor, that task is a bit time consuming. Here is information on
compressor sizing.

With reference to how much air a compressed air cylinder will use
here's info on cylinder air consumption.

There's no shortcut in the process, unless your compressor vendor will come in and do a site assessment for you, with the expectation that you'll be buying an air compressor from him or her. You have to think about all of the compressed air tools you might have, all of the air-driven equipment you might need, determine if all of what part of it will be operating when, and take that into account when determining the compressor size.

While it's unfortunate, but also a reality, when you are estimating compressed air consumption in your plant, allow 5-10% for wastage and air leaks too.

As to the compressor receiver or air tank, the rule of thumb for receivers is that they should have 1 gallon of capacity for every CFM of compressor output. Therefore, since a 25 HP compressor can theoretically generate about 100 CFM at 90 PSI, the receiver for that compressor should be 100 gallons in size.

Here's information on compressed air receivers / tanks.

I hope this helps.

Cheers,

Bill




Comments for
How to calculate required air pressure in a factory.

Click here to add your own comments

Dec 05, 2011
 volume Calculation
by: A.Lingeswaran

Hai sir this is very useful in carieer thank u very much and one question what is the formula for Compressed air calculation like (22/7)*d2*L/4

_____________________

Sorry, I'm not getting the question. What is the formula for compressed air calculation to do what? What are you trying to determine the air calculation for?
Jul 14, 2011
 calculate compressor air usage
by: KAMRAN

HOW TO CALCULATE THE COMPRESSED AIR IN PET COMPANY HOW TO GET HIGH EFF% OF COMPRESSORS

_______________________

Please see earlier posts on this subject, and then read the pages linked from SIZING in the navigation bar.

Cheers,

Bill
Jul 13, 2011
 compressor air
by: kamran

How is calculate compressor air and what is the formula of cfm,

______________________
Bill says... typically you can expect around 4 CFM of compressed air at 90 PSI per horsepower of compressor motor.
Jun 24, 2011
 REQUIRED AIR FOR FACTORY
by: Anonymous

1. HOW TO CALCULATE THE COMPRESSED AIR IN SPINNING MILLS.
2. HOW TO GET HIGH EFF% OF COMPRESSORS

____________________________
Bill says....

As to the consumption of compressed air in your spinning mills, there is no substitute for finding out what the air demand is of each compressed air consuming piece of equipment, and adding them together. If you have many machines with the same air consumption that, of course, makes it easier.

Check out the SIZING page for more details.

If the drive is to reduce energy costs by improving the efficiency of the compressor, not much chance of that happening, once you have purchased the compressor. What you can do though is use the compressed air more efficiently. Run all equipment at the lowest MOP where it does the job.

Check every air line and piece of equipment for air leaks. I believe it is the NFPA that suggests that more than 10% of all compressed air made is lost due to leaks. If you stopped all leaks in your plant, and that was the 10% loss referred to, you have just reduced your compressor energy consumption by that factor.

Looking for a new compressor? Strides have been made in making compressor efficiency improvements. For details on specific compressors, you need to talk to their people.

Cheers,

Bill
Mar 18, 2011
 how to convert kg.cm into cfm
by: Neeraj Bakshi

we are puting nearly 120 new machines and air pressure required is 6 .5 bar.iwant to know as per your suggestion to get new air compressor what type&
also how we can calculate cfm from kg/cm"2

or
from bar to cfm caculation

____________________
Bar is a measure of pressure. 14.7 PSI equals one Bar, and one Bar and 14.7 equals one atmosphere.

CFM is a measure of flow.

You cannot convert pressure to flow, at least, no way I know of. Anyone else?
Mar 03, 2011
 Air pressure Calculation
by: Anonymous

hi friends,
i am vishnu, please answer me my question how to calculate air pressure using sensor any sensor please send details this mail id vishnukumarab@gmail.com

please help me friends thank u
Jan 25, 2011
 To choose Right Air Compressor
by: Raja

I have 10 Air cylinders operate in same time for 6 minutes. I would like to know the correct type of Air Compressor( It is Single & Two Stage ). The Spec as per below:-

1) Each cylinder size: 100mm(Bore) x 300mm(L)
2) Total Cylinder : 10 nos

QUESTION:-

1) What is correct type of Air Compressor is required?
2) How to calculate CFM?
3) The size of Storage Tank

Your prompt reply is highly appreciated

Thanks & Regards
Raja
MALAYSIA

_____________
Hi Raja:

1) Whatever type of air compressor that has enough flow, fits your budget, has local support for maintenance.

2) Use the available air calculator from this site, do the math yourself, or hire an engineer to tell you.

3) My rule of thumb is to get a tank as big as you can afford, and one that is in keeping with the compressor size. Compressor size is predicated on how much pressure and flow you need. This information is provided in detail on this site on the pages about compressor tanks, sizing a compressor, selecting a compressor and so on.

Bill
Dec 15, 2010
 how to make right choice on compressor size to be installed
by: Fazlan

our plant already have compressor with 706cfm..
but, 2 major process (blasting & coating) cannot be run at the same time because of pressure drop..
i planned to installed (add) another 1 compressor so that both process could be run simultaneously..
do u think i need to install another same size of compressor or bigger? say 900cfm..what kind of accessories do i need for new compressor?
looking forward for your advise..

thanks~
_______________

The first question that has to be asked before deciding on a new compressor is, is it big enough to do the job?

You say you cannot run your blasting and coating operations at the same time due to insufficient compressed air flow.

What you aren't telling us, and what is critical to know, is the demand of these two processes in PSI and CFM. Until you know these numbers, when it comes to buying a new compressor, you are just guessing. The problem with that is, sometimes you guess wrong.

Cheers,

Bill
Nov 24, 2010
 What size of air compressor
by: Mehul Panchal

Dear sir
I have 2" upset forging machine, how I will know which size of air compressor I should buy & what size etc
Oct 26, 2010
 calculation for air comp
by: sunil

how to calculate the air compressor for actual consumsun air

_______________________________
Bill says...

Before you decide on the size of compressor to buy, you need to calculate the amount of air your applications will require.

There is no shortcut.

Please visit the Sizing pages on this site for details of how to do that.

Cheers,

Bill
Oct 12, 2010
 how to calculte the cfm
by: sanjay

Our compressor is 90 cfm at 7 bar pressure How to calculated actually the compressor generated 90 CFM at 7 bar pressure? Pls sanjay
Jun 15, 2010
 How to calculate air compressor requirement
by: Ravinder

Dear sir how can i knew what should the capacity of the air compressor if for example i am using coventional paint spray gun working at a pressure of 4 kg/cm2 and working 8 hrs continously and what if i use others gun at the same time? this air compressor must be attached with air drier so what should be the specification of the drier required

________________________
Bill says...

You need to add up the CFM and pressure requirements of all of your air using appliances, allow - say - 10% for system pressure loss, and whatever allowance you expect for plant demand growth, and that's about what you will need in compressor size.

Remember, you get about 4 CFM of compressed air at 90 PSI for each HP of compressor motor.

Cheers and good luck.

Bill
Jun 04, 2010
 To calculate air in cfm for our factory
by: ramesh babu

sir,
we are the leading shoe manafacture. already we have 30 kw compressor two nos still we have lot of problems in air,so please avice to solve the problem or give any calculation formula to calculate the air in cmf with the air pipe lines.

thanking
Ramesh

___________________
Ramesh, if your staff are not comfortable or capable of doing so, then you need a local compressor vendor to come into your plant and do a compressed air audit.

There are no shortcuts, that I know of, to determine the compressed air requirements of a factory.

B.
Jun 03, 2010
 find out factory load
by: ved prakash

how can we find load in cfm of factory.if any formula is possible.

________________________
You need to go to the page "Sizing" and read it all. It will provide guidelines to sizing a compressor.

I know of no formula that can do this for you. Perhaps the industrial compressor manufacturers have a method they can suggest. My way is to estimate the applications, and go from there.

Good luck,

B.
Nov 05, 2009
 What size of air compressor we need
by: hasan

Dear sir,

i want to flushing 12inch well and depth around 30 meter for cleaning the hole. so, can u suggest to me, which size of compressor is suitable for us (PSI and CFM). U have formula to calculate?





Howdy, and thanks for writing in.

I'm sorry though, I really don't know what it is you are trying to do. What do you mean by flushing for cleaning the hole? Are you trying to force water out to empty the shaft?

Perhaps you might provide a bit more info? Thanks,

Bill
Mar 14, 2009
 What size of air comresoor we need
by: Ashish

Dear sir,

We are in seat manufacturing unit.
We hane a 250 CFM ; Atlas make compressor having
motor rating of 37 Kw.
We found loading of this compressor is only 2-3 hrs. out of total 11-13 running hours.
Will you please suggest from above data which size of compressor is suitable for us, so that we can reduce energy consuption.


Thanks & Regards,
Ashish Patil






Bill answers...

Hi again, Ashish.

I don't see the horsepower rating for your compressor in your comment. Each HP of motor will generate about 4 CFM of compressed air at 90 PSI.

Based on the numbers you provided it would appear as though your compressor is actually providing compressed air about 27% of the time.

If you downsize your compressor, you need to be sure that you'll have enough capacity if your demand grows.

That being the case, if I were you, I'd pick a compressor with about 50% of the capacity of your present one.

Does that make sense?

Cheers,

Bill

Click here to add your own comments

Join in and write your own page! It's easy to do. How?
Simply click here to return to Sizing A Compressor