connect two air compressors together ??

by pete
(NY)

can I connect two air compressors together to increase air capacity?

________________
Simple answer.... yes!

You need to tee the outputs to your shop air. And you need to put a check valve in each output line from the compressor before that line gets to the tee.

You will want to adjust the pressure switch settings periodically so that the same compressor isn't coming on all the time, and the other sitting idle, if that's a concern for you.

Essentially, once the air demand drops the tank pressure to cut in, the compressor will start. If demand continues to drop the tank pressure, with the right switch settings, the second compressor will come on to add more air to the lines too.

Bill

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Feb 28, 2014
2 air compressors working alternately
by: Anonymous

Hi, I have a tire shop which utilizes 2 identical air compressors which feeds a single air line. I use each compressor alternately each day. M-W-F for comp.1 and T-Th-S for comp.2 The problem is, there are days when one air compressor is used heavily and there are days when the other compressor isn't used at all.

I'm concerned about the wear and tear of each air compressor, so I was wondering if there is a switch or a device that would control both compressors to run alternately. I think with this setup, it will balance the wear and tear of both compressors.

Can you help me with this idea? Thanks!
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I understand the concern, and, aside from manually shutting down one versus the other when the heavy days do not coincide with the compressor use, with your present system, you are stuck.

You need to move into the realm of electronic controls, one that will monitor compressor run time and and a pre-set interval or usage set point, shut down one compressor and start the other.

There are lots of small PLC's that will do this, some that you can program in plain language. This is not my area of expertise.

You will need to contact a local industrial controls company to provide and program and install a PLC into your compressor systems to accomplish this, if you do not have the skills on staff.

Bill

Feb 10, 2014
connect 2 screw compressors
by: Anonymous

I have 2 compressors (screw type) with different operation pressure : 8 bar & 9 bar. I would like to know whether I can connect both of them to 1 receiver and make sure that they can work simultaneously (assit together)
And please advise me how to install properly.

Thank you so much!
___________________
All of this is covered on the pages of this site already. Enjoy.

B.

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Connecting 2 compressors to get combined pressure and volume.

by Yasser
(INDIA)

In order to achieve the desired pressure and volume for our pneumatic equipment, I need to inter-connect 2 compressors.

I need advice on how to go about doing it and need a couple of questions answered:

1) Is it necessary that both compressors share the same specs ? and 2) Will the resultant pressure and volume be a sum of both compressors?

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Bill says...

Both good questions, and both covered extensively on the pages of this site already.

Answer to question #1 - no.

Answer to #2 - no. If each compressor puts out 100 PSI, your downstream air line will not see 200 PSI. What you will do is increase the available compressed air flow at the pressure the system needs.

Both compressors will plumb to the same air main to your plant.

Both air compressors will have a one-way or check valve in their lines before the two lines connect to the single main.

In order for one compressor not to be the one that's always on first, undergoing greater wear, periodically change the pressure switch settings so that the alternate compressor comes on first.

Have a look at Plumbing, Add A Tank, Add a Compressor, and other pages on this site for more details.

Cheers,

Bill

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I need information on plumbing a second compressor in line at my shop

by macolm powell
(mount dora Fl)

I need information on plumbing a second air compressor in line at my shop. One is a 6 hp, the other is a 5 hp.

____________________

Bill says...

Hi Malcolm:

Adding a second compressor is a good way to back up the main, and to help ensure lots of air when the shop outstrips the capacity of the one compressor to supply compressed air.

What some folks will do is adjust the pressure switch to allow one compressor to start first, and only when it's incapable of keeping up, having the second start at a lower pressure level than the first.

Both compressor discharges can be plumbed into one line. You will want to put a check valve in the outflow line of each air compressor before they tee together into the main, to stop air from flowing from the running compressor into the stopped one, and out the unloader valve.

Hope this helps. Check out the plumbing pages on this site for more detailed info about hooking up compressors.

Cheers,

Bill

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Manifolding 2 air compressors

by Bill Palmer
(Asheboro, NC)

I have 2 industrial air compressors. Both are 220v 3 phase with one being a 7 hp, the other a 5 hp. I am wanting one compressor to be the primary while the other acts as the secondary to kick during high peaks when compressor 1 can not keep up with peak demand times.

I know there are a couple of different ways these can be plumbed together but, am not certain of the best or most recommended way to pipe these up.

Suggestions and experience would be greatly appreciated.

______________________
Bill says...

Hi Bill... I get this type of question about putting two compressors together to increase flow and or have a backup for greater demand, quite frequently.

The frequency of the back-up compressor switching on will be predicated on the pressure switch settings of that compressor. If you have the cut in pressure just below the cut-in pressure of the primary compressor, then the secondary will only come on when the pressure level in the primary tank falls below the normal cut in, suggesting that even though the primary compressor is running, it cannot supply enough air. At which point the secondary compressor would start too, even though the primary would be running as well.

Both compressors can be plumbed to the same main. Assuming that both lines go to a common tee, and the out port from the tee goes to the air mains, ensure that you have a check valve in the line from each compressor to the tee so that air from one compressor doesn't back flow and out the unloader valve on the secondary.

Any further questions, please add them as a comment here so I can follow the thread.

Cheers,

Bill

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Jul 21, 2011
Good Advise
by: Bill

I appreciate the comments and recommendations. It all makes perfect sense now.

Jul 19, 2011
Check Valve...Type?
by: Anonymous

In using a check valve on each of the 2 compressor out feed lines, what is preferred? A swing check valve or a spring poppeted type? Seems to me a poppeted... that way you could mount other than horizontally.

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The check valve preferred is the one that works, and best suits the install architecture. Just make sure that it suits compressed air, and that it will stop back flow.

B.


Jul 19, 2011
Follow up question
by: Anonymous

Ok... so a check valve is recommended in the line before connection to the common Tee from "both" compressors supplying one mail line, simple enough. So it "is not" recommended to plumb the 2 compressors together side by side (one pipe from 1 compressor to the other)as I have heard of?
Animated diagram Below

..........Tee..................
. . main line >>
. .
..... . ..... .
. .--- . .---
. . . .
.C1 . .C2 .
. . . .
..... .....

________________

To my way of thinking, if you put the compressors in serial format, then the output from one simply backflows into the other. If, as should happen, the unloader valve on the secondary compressor is open, to dump air over the piston, then the output from the primary will simply flow down the line to the secondary unloader, and out to atmosphere.

If you want one compressor to be a secondary supply source, only coming on-stream when the first cannot keep up, then you do need, again in my opinion only, to have both lines to the tee with a check valve in them.

B.


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Garage Air Lines, Secondary Receiver, and Combining Compressors.

by Joe Martinelli
(Lake Worth, FL, USA)


First, yes I am a d-i-y'er and new to the understanding of compressed air. At home I have a working older Craftsman 110v/5hp oilfree 20-gal compressor that claims to put out around 5cfm @90, but is woefully underpowered. I also have a gas powered 5.5hp 9-gal wheelbarrow compressor that supposedly puts out 12.1cfm @100 that I will be using at my warehouse that has no a/c power.

After reading up on this site and others, I have a plan that I would like some feedback on. See the attached picture. I picked up a broken 26-gal compressor to use the tank as an additional receiver. I am considering buying the Complete Garage Air Kit from Harbor Freight to plumb as pictured. My questions are many: 1.) Can the additional receiver be as far as 50 feet from the electric compressor? 2.) Can I add the gas powered compressor near to the additional receiver to use in combination with the electric compressor? 3.) Will I actually approach 17cfm with this combination?

Thanks!
Joe M.

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Bill says...

Hey Joe. Good to hear from you. The short answers to your questions are:

1) Yes
2) Yes
3) Doubtful

You can't run a 5HP compressor with 120 volt power. There's not enough juice there to power a 5 HP motor properly. Underpowered it is, for sure.

As to addressing all the implied questions, let me say that all of the answers you seek are on the pages of this site, and it doesn't make a whole lot of sense to me to re-type all of the existing info here.

Please start with the Plumbing page, and go from there. There's info on adding a tank, adding a second compressor, and so on. Use the site map page to zero in, and/or the search engine on that page.

I envy you your proposed setup.

Cheers,

Bill

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what is the best piping system design layout for two rotary compressors

by tim
(edmonton)

i have to install 2,rotary compressors with a wet reciever,a dry reciever and a dryer.i am wondering what is the preferred piping system layout for an efficient system.

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Bill says...

Tim,preferred systems are what best suit the application, and what your budget can handle.

Installation information is provided under COMPRESSOR ISSUES, linked to PLUMBING COMPRESSED AIR. After reviewing this info, if you have specific questions, I would be pleased to help.

Cheers,

Bill

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setting up a 2 compressor system

I have 2 similar compressors , i want to have them set up so when the primary gets behind and can't keep up with demand the other one comes on and helps it out at peak useage times. do i need some special switch to do this?? can someone give me an example of how this works correctly?

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Bill says...

Nope, no special switch. You just use what comes with the compressors, with a bit of creative compressed air plumbing. Have a look at the TWO COMPRESSORS page linked from the site map.

Cheers,

Bill

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What are the precautions to connect 2 air compressors together on same air line?

by Abdo Zaky
(Cairo, Egypt)

Compressor Model: Sulair 5500
Air pressure : 120 psi

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Bill says...

Hi Abdo.

First off, though it was a nice photo, I didn't think it suited the site or the question, so I deleted it.

Second, I've written about this issue on a number of pages. Why not visit this page for info on plumbing two compressors together?

Cheers,

Bill

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Adding compressor

I have a 50 compressor in my air system.
I need to increase capacity.
I am thinking to add another 50 hp compressor.

How would the new compressor connector ?
Can it be connectod before the curreent receiver tank ?
Do I need a need a second receiver ?

______________________
Bill says...

Howdy. All questions asked are already answered on the pages to do with plumbing, adding a tank, a second compressor, compressor water etc. linked from the nav bar and site map.

Please have a read of the info already here, and if you have questions after about items I don't cover, I would be happy to answer them.

Cheers,

Bill

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About plumbing compressed air

by Stan JauJou

My company is starting a granite countertop fabrication operation. Adding up all of the requirements of the machinery and tools, I will need a peak of 108 CFM at 100 PSI. I am planning to route the compressed air in a loop around the shop. Most of the equipment requires clean, dry air. However the hand tools require oil lubricated air. What is the best way of delivering the lubricated air to a small portion of my shop? Will a 1" main line be big enough? Thanks for your help! Any suggestions will be greatly appreciated!







Bill answers....

G'day Stan:

Good that you're planning to run your air main in a loop. Make sure that it tilts to one corner where you can have a drop leg with an auto drain to help reduce water.

Also, make sure you take your drop feeds (except the drop leg drain) off the top of the main, to help reduce water migration down to your equipment.

Where you are planning to use hand tools, can you make a drop leg into a horizontal run? Put a lubricator there, and then feed that air into a manifold from which you can run hoses to your various tools. That will help get lubrication to them.

The other thing you can do is put in-line air tool lubricators for each hose that goes to an air tool. The lubricator can be located quite close to the tool, and this will ensure a steady supply of oil to the tool.

While bigger is better in terms of air main size (the air main then acts like another reservoir, allowing air to cool and shed water) it sounds as though a 1” line should work, although without knowing the dimensions of the shop, it's hard to be certain.

If it's a large shop, put a reservoir (another tank) at the farthest location from your compressor, which will fill during low demand times, and feed air both directions your main as the demand is generated by tools and equipment cycling on.

Cheers,

Bill

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adding an extra air tank

by cag
(asia)

my air compressor

my air compressor

i have a reciprocating air compressor (1/4 hp ,pressure of 9kg and has a 9gallons air capacity)

Just wondering i want to add a extra air tank in it, what things i have to consider and do you think, will the motor can put up, if i add a 2nd tank.do you advice to add a 2nd tank or not??? Thanks

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Bill says...

Howdy Cag....

An extra tank is, in my opinion, always a good thing for the many reasons noted on this site.

You need to be concerned about the Duty Cycle of your air compressor, so that, if it is not 100% duty cycle, you don't run it to overheat.

Why not pop over to the site map and have a look at the Plumbing section, the Tank section to get details about adding a tank.

Cheers,

Bill

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