# air compressor - dangerous????



## Sammy (Mar 11, 2007)

The bleeder valve should be brass and shouldnt rust. 

As long as there are no obvious signs of major rust on the tank you should be fine. 

Drain it and leave the valve open til the next time you use it. That will remind you to open it after the next use.


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## MinConst (Nov 23, 2004)

Drain it. If it hasn't been drained in awhile it needs it. A 2 yr old unit should be in fine shape. Be sure all the air pressure is out of the tank before turning the valve. The reason you need to drain it is that water collects in the tank and rusts it out. But unless it i a really cheap piece of crap it should be fine after 2 years. You don't need to drain after each use. That's kind of overkill.
I've had compressors for years and didn't drain them. It depends on how much moisture is in the air where you live and where the machine is.


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## reds_21 (Sep 13, 2007)

thanks sammy

now i understand that part of it but what is the best choice to open the valve now?? it could very well be a brass valve, maybe it wasnt rust but more like corrosion due to the water. how can i find out if there is rust inside the tank???????

would i be better off buying a new plug? and starting over on a fresh slate? 

my air comressor is a craftsman 30 gallon, 150psi compressor. i cant exactly see inside of it.


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## reds_21 (Sep 13, 2007)

minconst

well if you consider craftsman crap,,,thats what it is.

i live in ohio, so the moisture is greater in the summertime, and whatever the winter adds probably doesn't help either. the compressor is stored in the garage.

what is the best way to see if theres any interior rust??????


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## slickshift (Aug 25, 2005)

You'll know
When you let the air out (by the bottom valve) it will also let out water, which will be rusty

The (actual) bleeder _valve_ may be brass and not rust, but the rest of the piece (the parts outside/other than the actual _valve_, but still part of that piece/unit called "the valve") can rust and/or can clog with rust

Replacing the valve (unit) is simple and the part should be in any Sears/K-Mart compressor section


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## AtlanticWBConst. (May 12, 2006)

It takes alot of compressor use and alot of non-bleeding of the tank's air/moister - over time to corrode a tank to the point of degredation and this result: 

http://www.doli.state.mn.us/airtank2.html


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## robertcdf (Nov 12, 2005)

It would not explode when you drained it... IF it were to go it would be when you turned it on next. (when it reached a high enough pressure to burst at a weak point)


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## jiggyjack (Mar 30, 2007)

Steel rusts-Compressor tanks are made of steel-Moisture increases the pace at which steel rusts-Air compressors create moisture-ALL COMPRESSORS WHICH HAVE BEEN USED ARE RUSTED ON THE INSIDE.

Point being; Try to drain your tank at least once a week and don't be to worried. Usually your tank will leak before it blows. My policy is replace the compressor every 7 years, even if it is still running. I have twelve compressor that rotate in and out of use and I have never had one blow.


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## Sammy (Mar 11, 2007)

I agree that they all will have rust in em.. 

But a total tank failure versus just spring a leak on a weld would be extremely rare. [cool pic AC!] 

Drain the tank on a regular interval and it should be fine.

We have a small 1.5 gallon or so compressor at the shop that runs an air drive key machine. Runs all day long and gets drained weekly. Some rusty water comes out every week. Been in use close to 20 years and hasnt failed yet.


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## reds_21 (Sep 13, 2007)

thanks everyone. so it isn't the draining of the plug that will cause the compressor to explode but rather the non-draining. right???

so as long as i drain from here on out i should be ok??

does the tank need to be empty (no air) before draining?


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## Sammy (Mar 11, 2007)

Failure could be caused by the rusting at a critical point, a weld failure, or even a crack in a steel area that wasnt even welded. 

I drain mine with a little air pressure on it and since mine is only a 13 galllon, I shake it around a little to drain the water and leave the valve open til the next use. 

If yours is only a few years old, just drain it on a regular basis and it should be fine for many years to come.


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## MinConst (Nov 23, 2004)

reds_21 said:


> thanks everyone. so it isn't the draining of the plug that will cause the compressor to explode but rather the non-draining. right???
> 
> so as long as i drain from here on out i should be ok??
> 
> does the tank need to be empty (no air) before draining?


YES / Yes / Yes


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## fireguy (May 3, 2007)

Open the drain valve, drain the water w/air pressure to move the moisture out of the tank. The drain valve is to be at the bottom of the tank. You do not say if the valve is accessable or not, but you can use 1/4 inch brass fittings and move the valve to a more accessble location if you choose.


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## reds_21 (Sep 13, 2007)

thank you everyone for putting your words of advice/instruction in.

i went ahead and opened/removed the valve last night and all is god. the valve is bluish/green due to corrosion but when the water started to drain out, i couldn't tell if it was muddy water or rust water but a good amount did come out!!!!! i left the drain plug out so all of the water would drain and the tank would hopefully dry. im going to replace the drain valve with a new one in hopes of it opening/closing with ease. in order to open/remove this valve i had to use a pair of channel locks. it was really tight to remove!!

so once i get the valve, it will be back in working order and drained weekly!!!

thanks again :thumbsup:


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## fireguy (May 3, 2007)

When you replace the valve, use a 1/4 turn ball valve.


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## tazmon3 (Sep 21, 2007)

reds_21 said:


> i have an air compressor question. i have had my air compressor for a little over two years. i dont use the compressor a whole lot, mainly to blow up car tires. on the compressor it has a label that says after each use, you need to release the water from the bleeder valve. heres where i am very worried. since i dont use it that often i have neglected to do this. the times i have released the pressure/water, the bleeder valve is pretty rusted. i haven't bled the valve in awhile.
> 
> the sticker says if you do not do this an explosion may occur causing an injury or maybe worse.
> 
> ...


The reason you need to bleed water from your tank is because the tank will rust when water is in it. Since there is almost always humidity in ambient air, the air that you compress will always put moisture in the tank, unless you have a drying system (which few, if any do-it-your-selfers would have). The reason you bleed the water is to keep it to a minimum to slow down the rusting process. A steel tank will eventually rust through though, even if you bleed it, but hopefully not as fast. 

I had a tank that did rust through, but it didn't explode. It developed pin leaks in the bottom. When they got big enough for me to hear the air escaping, I stopped using it and replaced the tank. 

When you consider that psi is literally the gage reading, times the total square inches of the tank, the pressure exerted on the entire tank can be in the thousands of pounds, which a new tank can contain. However when the tank is compromised the amount of pressure it can contain deminishes. It's unlikely that the tank will have a catastrofic failure, but if it did, it's conceivable it could do unbelievable damage to the surrounding area, as well as to anyone near by. You would be wise to bleed it often and to keep an eye and ear pealed for leaks. Also empty the tank of it's pressure and replace the valve asap. And, use the same type of valve including the metal it's made from.
Hope this helps,
Tazmon3


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## allenc88 (Sep 24, 2007)

*In addition*

Hello all, I'm a newbie with concerns about my air compressor too. I surfed and got this link and registered for "dangerous" air compressor. Without having to start a new thread, I wanted to add to this.

Likewise I haven't use it for awhile and when I started using it I noticed that the auto shutoff pressure knob wasn't shutting off at 80lbs like before. I turned it off at 110 lbs before it got to 125lbs max. 

I know that it's not normal but having a fear of an exploding tank and still using it. At first I was tempted to just turn it on in the backyard and wait at a safe distance for it to do something like shutoff. Would anyone say this is normal and fixable or would I need to trash it? Thanks for your replies.


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## scrapiron (Aug 30, 2007)

To allenc88, most compressors have a pressure relief valve in case the pressure switch does not work correctly. I believe most pressure control switches are factory set to come on around 80 psi and cut off around 125 psi.


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## seobeglobal (May 15, 2007)

whether an ait compressor outputs a dangerous amount of static electricity for computers???


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## Ron6519 (Mar 28, 2007)

These tools come with instructions and maintainance suggestions. You should keep them by the unit so you can familiarize yourself with their requirements.
How would you explain muddy water coming out of the compressor tank?
Ron


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## unknownsoldierx (Mar 4, 2008)

I have a Craftsman 33gal 150psi compressor. The drain valve on the bottom is leaking. I am contemplating replacing it with a ball valve as I've seen suggested here and other places.

What do you guys think? Is it safe?


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## fireguy (May 3, 2007)

Ron6519 said:


> These tools come with instructions and maintainance suggestions. You should keep them by the unit so you can familiarize yourself with their requirements.
> How would you explain muddy water coming out of the compressor tank?
> Ron


 
Ron is it muddy water or rusty water? 

A vessel under pressure can explode, catastrophically. (Big noise, pieces of metal flying in all directions.) If a pinhole developes, the tank will leak and the comppressor may not be able to develope enough pressure to trip the shut-off switch. Many pressure vessels are required to be pressure tested periodically. Those vessels are not tested with air,but with a non-compressble liqued. the test pressures vary depending on factors such as working pressure, tank material, contents, mfg requirments and Fed-DOT requirements. 

UnknownsoldierEX, if you have concerns as to my knowledge and working w/pressure vessels, do not take my advice. I can understand your reticence to take the advice of an unknown person, so I will mention I have worked w/fire extinguishers, SCBAs,( some of which I used in fire situations) nitrogen tanks, dry sprinkler systems, fire suppressison systems for over 30 years. The pressures I work with range from 80 PSI to 2100 PSI. At present, my 5 service trucks are equiped with 2100 PSI N tanks and depending on the service required by customers, portable air compressors.


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## Ron6519 (Mar 28, 2007)

"Ron is it muddy water or rusty water? 
You would need to ask the original poster, these were his words.
Ron


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