Comnpressor Tank Safety

[Billy NY]

Well, I've got a little craftsman for airing up tires and cleaning, not much else, the darned valve on the bottom was stuck for awhile, finally got it out, 2nd one I've put on it, but the water was a little rusty, obviously you can't tell the condition unless you put a camera in there, are these things ticking time bombs if something like that happens, having water in there, say maybe a year, typically speaking here, as I know this is a specific one, ( my tank ) its a '98 model, 3 HP 12 gallon oil less. The darned thing has served me well, with a fair amount of use,

I have a 4 HP 20 gallon Craftsman, oil type compressor, have to put in the 220 line for it, was a $40 find, in nice shape well from the outside, no moisture in it, both have been in a heated garage.

Hate thinking about things that can go boom, always wondered how they typically go, big bang shrapnel, or leaks by the valve or the bottom ?

 

[Lanse]

They can do some damage when they let go...

I wouldnt take many chances with compressors...
Non bloody explosion pics

 

[Anonymous-0]

My great grandad had one explode in his shop that broke his arm real bad and a deep cut.

 

[Billy NY]

You are right Lanse, there really is no pressure vessel worth fooling with when it comes to something failing, or explosion... period.

I just forwared that link to my father, he's got this old one in the barn, I've said it a 100 times.

Those photos, make me want to toss the darned thing now or find a new tank or something affordable, hate to say its not in the budget, look at those photos man, and the guy with lacerations and broken bones..... cripes I'd in a world of crap if that happened to me right now, can see it now, blown eardrums, busted up bones, scraps of metal stuck in ya.

PS like what you have been doing in the shop, you've really done well with welding so far !

 

[Stephen Newell]

I wouldn't worry about them. They will develop a small hole and leak before anything serious happens. The leak is a warning sign their done. It's usually when people ignore the warning signs or start trying to patch them when their ready to retire they go boom. Just keep the water drained especially in humid weather. I have two old compressors, a portable one that was bought in 1988 and a industrial size one bought in 1992.

 

[KLS]

Often small tanks like that have what are called "tell tale" holes in them, which are holes spot drilled in the shell that don"t go all the way through. When the tank rusts these spots will rust through first, which will make the tank leak but still have the structural integrity to not go boom. Asme approved pressure tanks have a very high factor of safety built into them, like the shell could be half as thick as it was and still be more than strong enough to hold the rated pressure. The fasted way to blow one up is to over pressurize it and rip the metal. Ultra sonic testing could tell you how much metal you have left, some manufacturing shops have them.

 

[kencombs]

From the looks of that picture, the first thing to go was the weld. Notice how it split cleanly along the seam of the end cap. And, very little rust thinning apparent anywhere, at least what I could tell from the pic.

 

[jbp]

Just put a new tank under my 35 or so year old Craftsman 2 cylinder oil bath compressor. Found a new tank at Surplus Center that required only one modifacation for the compressor inlet line. After completing the job, I removed the air filter on the compressor and slowly let oil drizzle through while running to allow the tank to be coated and hopefully slow down rust from the inside of the tank. Joe

 

[The Red]

That is more than enough motivation for me to buy a new one and scrap the old Craftsman.

 

[sotxbill]

150 lbs on a tank that was rated 120?? bad gauge?

was it really at 200 lbs?

 

[PJH]

Isn't 150 PSI a lot for that type compressor?

I'da chickened at 110.

 

[Russ from MN]

Why would anyone run that kind of compressor up to 150, your asking for trouble! I used to have one that I didn't trust and I would wheel it out behind the shed when I ran it up to higher pressure, (100psi).

 

[Mark - IN.]

You make a good point. I try to drain my tank everytime I use it for that reason, but in all honesty, do not.

Draining tanks were mandatory when I was in the Army. Bottom of 5 or 2.5 ton trucks. Shop compressors. Mandatory, for that reason, and with good reason.

And speaking of tank explosions, was not a compressor tank, but rather a beer keg. I posted about this before. Happened a couple of decades ago at a party where the party throwers didn't want to have to continuously hand pump the keg, and thought thy could pressurize it, not knowing that a keg (at least back then) held about 12 lbs of pressure. They didn't regulate it and had no idea about the low pressure, and I remember that at least one person was killed and serveral hurt seriously when it went off in the middle of the party.

Gotta be careful, and somtimes I'm a walking disaster looking for a place to happen, myself.

Mark

 

[buickanddeere]

How could somebody so cheap and in love with the almighty dollar? To pick having a few $$$ in the pocket over the risk of a tank explosion?

 

[Stephen Newell]

I believe if compressors were all that dangerous, OSHA would make them put an expiration date on the tank. They don't because it is a extremely rare event for one to rust through. I've been around compressors for 40 years and have only seen one that had exploded and that was because it had multiple repairs.

 

[Billy NY]

Who are you talking to like that ?

 

[Billy NY]

About the first and last time I've ever even responded to someone being rude on YT, now you're just downright abrasive, stuck both your hands in a panel one too many times and got bit have ya ? Sheesh man, you sound like one miserable sob,whats with that and here, serves no good purpose ... good day sir !

 

[buickanddeere]

(quoted from post at 23:25:46 03/21/12) Who are you talking to like that ?

Talking to Stephen Newell and anybody else who thinks using a rusted out tank is acceptable.

 

[dr sportster]

If it is like mine it will start to leak at the bottom through pinholes of rust. When this happens ya you could get a plate and bend it around the bottom of the compressor and weld up the whole thing but at that point the safest and really cheapest thing is to get a new compressor. By that point that compressor has made you so much money and finished so many projects that you will replace it and enjoy the warm ,fond memories. I don't like the idea of welding on a closed vessel.I read a book about Plant Disasters with a chapter called" Explosions in extremly lean mixtures".That would keep coming to mind as I tried to weld.

 

[Billy NY]

I would absolutely agree with that, the point of my question was just that, (when or what tell tale sign if any, is there as to raise concern about the integrity/safety of the tank) Even with meticulous maintenance, when or how long of a service life do you get out of these, realizing its a closed, pressurized vessel, that you cannot inspect, just hydrostatic test per the certification data plate, (in my case, it was certified in '99, by Devilbliss, for 150 PSI @ 350 F) there's the safety margin, my regulator is set at 120 PSI and works fine, but it does leak when you increase the pressure on the hose, like over 80 PSI.

For the most part the water was drained as per the owners manual and instructions, there is a safety sticker on the tank explaining the hazards about not draining water and tank rupture, leading to serious injury or death, understood. I guess I was just wondering how detrimental standing water is to a compressor tank say over a year's time, in the conditions I describe, a heated garage, annual temp variance is 55 deg F to 70 deg. F, not much to cause condensation when idle.

As of right now, it has a new drain valve, and is holding 110 psi, I will leave it at that for 24 hours and see if there is any leak down. Given the age, I will either source a tank or a similar size unit, or a much larger more useful one. No way would I even attempt repairing a pressure vessel like a compressor tank.

In the interim, I will check my other one, 4 HP 20 gallon, it was drained and stored since 2008, not much water and it was clear.

Part of the reason I posted this was to seek opinions, but to also raise awareness through the ensuing discussion, for everyone's benefit, most here have a compressor of some type/age I would imagine.

The intent was clearly not to instigate other participants (who shall remain nameless) to respond with an abrasive and seemingly rude tone, which in effect serves no purpose on this or any other forum,discussion or conversation. The same point could have been made in a more polite and friendly manner, commanding some respect, showing intelligence and an otherwise friendly tone !

PS, I did enjoy the moderator deleting some of this last night, was not my intent to violate the friendly atmosphere on YT by any means.

 

[Mel in SW Iowa]

I brazed up the rust pinholes in a 15 gallon portable compressor my dad had and 5 or six years after that when it was in my garage, it split open like when you used to put an M80 under a peach can. It damaged a walk in door and about 4 sections of sheet rock, ending up about 20' from where it started. The shutoff switch was set at 120#. K don't know whether it was the switch or the pop off valve or neither.

 

[Stephen Newell]

You know that attitude is probably why your first message got poofed. You are free to express your own opinion as I did. It's up to each individual to make their own decision. Leave the personal attacks out of it.

 

[buickanddeere]

(quoted from post at 17:38:43 03/22/12) You know that attitude is probably why your first message got poofed. You are free to express your own opinion as I did. It's up to each individual to make their own decision. Leave the personal attacks out of it.

Entire message is still there in Modern view but appears edited in classic. No need to apologize to some money grubber that will trade safety for a few bucks.

 

[Doug in Illinois]

I have been wondering if my 6 gallon portable air tank is still safe. The portable tanks don't have drain cocks in them.

Of course I know to keep it at or below 125PSI, which is the rating for the tank.

It has a DISCARD ON date stamped into it of 12-1-2007.

Another tank I will no longer use is the freon tank to air tank conversions. I have heard of them blowing up.

A brand new 11 gallon tank from Harbor Freight is $34.99. I don't want to lose my life or be badly injured from not spending the money on a new one, but wondered if there is a real danger or if they had to put the date on it for liability reasons in case the tank had been abused or used every day, which would introduce more water vapor into it. Hate to discard it, BUT???
DOUG

 

[buickanddeere]

Figuring how so many folk have money and time to waste with an oil/filter change every 3000 miles instead of 10,000+ . Add that $ up over the years. On a fuel injected engine burning unleaded gasoline. They should be able to find $ for a pressure tank that is leaking.

 

[showcrop]

As we all expect there is a broad range of responses to this interesting topic. So we all need to use common sense and recognize that age is not the whole answer but also proper maintenance and a realistic life span even when well cared for. And probably not try to patch them, but not replace every month like B&D apparently does.

 

[buickanddeere]

Showcrop how do you expect to be taken seriously after
wording a lengthy speach . Then spoiling the whole essay with
such a rediculous closing remark?

 

[showcrop]

(quoted from post at 20:40:29 03/22/12) Showcrop how do you expect to be taken seriously after
wording a lengthy speach . Then spoiling the whole essay with
such a rediculous closing remark?

SPEECH

 

[Stephen Newell]

Your compressor can pressure down without anything wrong with the tank. Even with a new drain cock some air can leak there or the couplers or any place plumbing is attached. What I meant by a leak is if you see any evidence of air or water coming through the steel itself. I've had three compressors rust out like that. I had one that I saw a wet spot on the floor under it away from the drain cock. I ran my hand under the tank and felt the small stream of air coming out like a nail hole in a car tire. It's then you need to retire the tank. Out of curiosity I let the air out of it and turned it over and hit it with a hammer where it was leaking and all it did is knock the paint off. I probably could have continued to use the compressor but at that time I deemed it unsafe and retired it. It is true there is potential for a air compressor to explode. At one time I worked part time as a newspaper reporter and I was called to report on a story about one that exploded at a diesel garage in the small town where I lived. It was a upright commercial compressor that the tank had rusted out. When the bottom failed the compressor took off like a rocket and went through the roof of the building and landed outside. When I went out to look at the compressor, the bottom of the tank was bent back like a flap. I then noticed several spots of brass on the bottom where they had been welding on it. I questioned the owner and he admitted they have been repairing the compressor for ten years. I neglected to ask what pressure they were running on it. Both the compressors I'm currently using have been showing a little rust in the water for as long as I've had them. I just keep an eye on the integrity of the tank and watch for air or water coming out of it somewhere where it shouldn't. On my larger compressor I keep the drain cock open enough it leaks a little water all the time. That way it doesn't accumulate a great deal of water. Then from time to time I open it up wide and drain it.

 

[Billy NY]

I cleaned up the compressor, tank and cover, checked for what you mentioned, none of that and it holds 100 PSI over night. I'll pay it safe and kick it off a little sooner than the regulator, which kicks off around 115 psi.

That vertical had to be sight, like the hotwater tank on mythbusters. Well one thing is for sure, "aint no" vertical compressor going in in certain places in my garage, being my bedroom is over one side LOL !

 

[don t-9n180179]

"The portable tanks don't have drain cocks in them."....

I got one of them 6 gal tanks for filling tires. I unscrewed the hose and replaced it w/a quick connect female connector. This allows me to use an air gun. Turn tank upside down and pull the air gun handle. I get some water on occasion, but not very much.

FWIW...don t. ....

 

[PJH]

Also. Ridiculous. Not that. It matters, just. Couldn't resist. . .

 

[Stephen Newell]

It's possible if you want to, you could adjust the pressure switch to cut off at a lower pressure. Most compressors have a sign on them saying not to adjust the pressure switch because many people adjust them the other way making the compressor run to higher pressure than the motor and tank can safely do. There is nothing wrong with lowering the pressure. The adjustment is often inside the switch so you will need to disconnect it from the power before you take the cover off the switch. There should be a screw or nut over a spring you can loosen the tension on to reduce the pressure. Sometimes there are two adjustments. One for the turn on pressure and another for turn off pressure. If it has a single screw after adjusting it will turn on at a lower pressure than before and turn off at a lower pressure.

 

[JMOR]

All a matter of chance & destiny.........I have a Curtis made in 1927, still running & holding 120#, drain it maybe every 5 or 10 years. A Develbiss or CH about 1990, tank rusted through bottom. What can I say? :roll:

 

[Anonymous-0]

It's interesting that you say it's rare for compressor tanks to rust out but you've replaced 3 tanks of your own because they rusted out. Hmmm?