Air Compressor - Would this work?

merc123

Senior Member
I'm curious if this would work and what I would need to make it work.

I've currently got a small 8 gallon, Husky oiled air compressor that I race with. It's not bad for some things like airing up tires and the occasional impact gun use, but now I've gotten quite a new use for air tools (air ratchet, cut off wheel, etc).

The building I house my race car in has some air compressors out back (50 gallon), but I don't know if they work. I'm going to contact the building owner to check and see if I can get them working, if not this is my idea.

Two of the 50-gallon air tanks are plumbed together, only one has a motor on it.

Would it be possible to hook up the 2, 50-gallon tanks into some PVC lines, then hook up my little 8 gallon and use it to fill the 50-gallon tanks? That way I have some reserve air and the little compressor wouldn't have to run continuously for 20 minutes while I use a cut off tool. I will turn off the little compressor and just use the reserve air. Then I can run the little compressor at intervals to fill the big tanks back up so it doesn't burn up.

See diagram
 

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Baby Bear

Senior Member
Merc,

It will work but that little compresser will run forever to fill those 2 tanks. You may want to look into fixing the old one or buying a larger model.

Jeff
 

jmharris23

Moderator
This is no help at all,but it sounds good.
 

Snakeman

Senior Member
Yes, it will work, but as previously stated, the small compressor will run for quite some time to fill the two 50 gallon tanks.

A safety issue to consider, it's not a good idea to use PVC pipe for air line. PVC is prone to catastrophic failure under pressure, and plastic blown apart by 100 psi air makes for some fine shrapnel.

The Snakeman
 

JW2

Senior Member
hahaha:bounce: I tried the same thing in my garage. Had a small pancake compressor running to a 22 gallon tank and 4 air outlets. I also used metal gas pipes. It worked ok but the compressor ran for a long time, burned alot of oil and eventually quit working.:banginghe
 

merc123

Senior Member
Hrmm.... I've got some PVC that is rated at something like 250 PSI on my trailer... I hope it doesn't blow up :)

They have existing PVC pipe in the building but it was weakened by a fire they had in the main building. A friend of mine uses PVC in his shop and his compressor (80 gallon) has something like 150 PSI unregulated running through the PVC...

What would you suggest for piping? Also, I will probably borrow the air line hose from my garage neighbor who has a 30 gallon upright compressor. If we put both my 8 gallon and his 30 gallon it should fill it up pretty quickly :)

I figure I could use the 100 gallons until I can get a bigger compressor to put in there.

Plus, this is all if they don't work and I can't get them working...
 

JBeck

Member
I think you may need to attach any appliances after the storage tanks if possible. That way your air compressor is "charging" both tanks and you can capitalize on your storage. I'm thinking that at some point you would deplete your tank pressure enough to equalize your pressure between your tanks and compressor. At that point you would lose the benefit of any extra air in storage.
 

Snakeman

Senior Member
merc said:
I've got some PVC that is rated at something like 250 PSI on my trailer... I hope it doesn't blow up
I hope it doesn't blow, either.
merc said:
What would you suggest for piping?
Stainless steel tubing.

The Snakeman
 

jav

Senior Member
use cpvc pipe and you will be fine, use it in my shop for fifteen years and never had a problem, also you are only dealing with air, not a combustable element
 

Nugefan

Senior Member
use cpvc pipe and you will be fine, use it in my shop for fifteen years and never had a problem, also you are only dealing with air, not a combustable element

combustable has nothin' to do with it ... compressed air is just as dangerous ....... not to be disrespectful .....:love:

I had it in a shop where I used to work and in the winter when it's cold you'd better be careful and not bump it ....... it will shatter like glass .....

there is some type that is rated for air .....

you want your compressor closer to the recievers if possible .....

please see attached link before ya do it ....

http://www.osha.gov/dts/hib/hib_data/hib19880520.html
 

Snakeman

Senior Member
combustable has nothin' to do with it ... compressed air is just as dangerous ....... not to be disrespectful .....:love:

I had it in a shop where I used to work and in the winter when it's cold you'd better be careful and not bump it ....... it will shatter like glass .....

there is some type that is rated for air .....

you want your compressor closer to the recievers if possible .....

please see attached link before ya do it ....

http://www.osha.gov/dts/hib/hib_data/hib19880520.html
Thanks, Nugey.

The Snakeman
 

GA1dad

Senior Member
Hmmm, I qualify to answer this. I used to be a industrial air guy.

The easy ones first.

The air tools should be after the storage tanks.

While the PVC "may" work, having it blow while holding back over a hundred gallons of #125 air is gonna be ugly. If you were lucky, you'd start with a small leak. But if it blows a fitting off, you've got alot of cubic feet of air coming out "right now".

Standard black iron (threaded) pipe is the industry standard. It's relatively cheap, and easy to install. Seal joints with pipe dope or teflon tape. You could use 1/2" pipe, but 3/4" would give you more "cfm" to operate the bigger (high output) air tools. Then you can make 1/2" drops off the main run. Also have one 3/4" drop if you need a larger CFM flow.


The tougher one.

While yes it would produce air, it would not act the way you are wanting it too. You stated that you have a 8 gallon tank on your present compressor. What is the cubic feet per minute (CFM) output of the pump? How long does it take to compress a 8 gallon tank to max pressure?? Imagine how long it would take to fill 2 more 50 gallon tanks, plus the hard pipe air lines.:banginghe It'd take forever. Then you'd still have the original problem. After a few minutes of usage, you're down to 60 pounds, and your air tools won't break a bolt loose. And your little pump is running for a half hour trying to fill the system back up. You would have a few more minutes of usage with the 100 gallon system before the pressure drops too low, but the time gained will not balance out the timed burned trying to fill it back up. You'd prolly be better off to keep the 8 gallon setup. While you will have to fill up more often,,,,, fill up time will be short, thus keeping your wait time down. Then you don't half to wait a half hour to break loose a big, bad bolt.

One last thing,

The pump on the 50 gallon tank is prolly pretty easy to rebuild. But a new replacement pump will be cheap, easy to replace and come with a warranty.

Safety, Safety, Safety!!!!

Make sure you have a "functioning" blowdown valve on **ALL** tanks!!!! These should be rated only slightly over the maximum working pressure. Also, there should be a one way valve between the tanks. These will open up at light pressure, allowing the air to fill tank to tank. But will seal off to keep the pressure from flowing back to it's source. That way if tank A blows, the air in tank B will stay contained in tank B and not make a bad situation worse.

Make sure each tank has a accurate pressure guage on it. It's the only way you can "see" that all is well.


For Gods sake be careful. A air compressor is a potential bomb. 100 gallons of 125 pound air can take the side off of a building.

If I can be of help, feel free to PM me. If you need parts, I can prolly point you in the cheapest direction.

Jay
 
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merc123

Senior Member
Good info.

I think I'll try to see if the current 50 gallon ones work. They've got PVC hooked up into it right now, but like I said it was heated and I definitely don't trust it. I bought some black pipe for my tire rack, and it was about $1 or so a foot at home depot.

If the 50 gallon ones don't work, I'll just wait to get a larger model from somewhere.
 

merc123

Senior Member
Yeah, I didn't think about pawn shops. I was looking more for volume than pressure because the max PSI for my tools is about 90-100 any way.
 

WishIwuzhuntin

Senior Member
A man was killed in my hometown when a tank on a compressor he built exploded. Compressed air can be VERY dangerous. I would be concerned about the condition of the tanks. You can't see rust inside of an air tank. It may look fine on the outside, but be severely weakened from corrosion inside. That is why draining tanks is so important. Considering the possible damage to life and limb, I'd say the cost of an adequate compressor is cheap insurance.

The thing that we take for granted is that 150 PSI, means that every square inch in a system has 150 pounds on it. That is 21,600 pounds of pressure on each square foot. Looking at it in terms of PSF instead of PSI makes it easier to understand the danger.
 
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