Air Compressor Tank Explodes

Tom Wesenberg

Well-known member
See the picture in the link and read my first post below the picture.

http://www.fordbarn.com/forum/showthread.php?t=28419&highlight=proof+big+bang

Yesterday I drove 250 miles round trip to pick up this nice little antique air compressor. The gauges are the standard 2" size, so you can see how small the pump is. When I went to lift it, I was shocked at how heavy it is. The cast iron tank must be at least 1/2" thick.

Tonight I was just thinking, this is the first time I remember seeing a cast iron air tank. You can see it's embossed on the side of the tank "TESTED 300 LBS". I'm not worried about the tank blowing up, but if it did, I would imagine it would fragment like a hand grenade. Is it still legal to make tanks out of cast iron?:confused:

BTW, how did pounds come to be abbreviated "LBS" when there is no L nor B in the word pounds?:confused:
 

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The unit is descended from the Roman libra (hence the abbreviation "lb"); the name pound is a Germanic adaptation of the Latin phrase libra pondo, 'a pound by weight'

From Wikipedia, which cites the Oxford English dictionary
 
old timers told me to open the tank (bottom and top) allow it to thoroughly drain and dry in the hot summer sun for a day, pour in a cup of motor oil, roll it around to coat the inside. Not sure if this really prevents and rust. Of course when you blow out the the condensation, the oil comes out too.
 
I go to a air compressor shop not far from my house for my parts. They have a picture hanging in the wall from around the 50' or 60's. An old brick building that had an upright compressor in the back corner. It exploded and took out the top of the roof and the back wall of the building. Part of the tank was found two buildings down. Yes they rust out and become missiles. :eek:
 
When I was young and stupid (as opposed to being old and stupid) I had a very "Primitive" compressor set up without a pressure switch or a tank. So I got an old hot water expansion tank and mounted it on the wall of my father's garage. I used the air to run a pneumatic air drill with a sanding arrangement to to sand the bottom of my first Chris Craft speedboat. I was working one day and the phone rang. I went into the house and forgot all about the compressor running out in the garage, until...... Until I heard a loud explosion. The tank blew the end off and launched itself across the garage to knock the boards off the wall . The compressor was still running. the tank was halfway out the wall. Actually, it only broke one board, the rest merely needed to be put back. A learning experience! I'm glad I was in the house at the time.
Terry
 
Tom

Thank you for sharing.
Nice little thing you found there. :)

Feel free to test to 300lbs - Distance between us might be big enough :cool:

Best regards
Christoph

BTW
Since 30 years i try to understand what size a 7/16-20" bolt might have.
And what i need to drink and to smoke to understand. :eek:

Once i understand that, i might start to wonder why there is no "L" nor "B"
in the word "Pound". :rolleyes:
 
Well this got my attention. I have a Campbell Hausfeld VT610202 air compressor under my workbench which is probably 20+ years old. It was used quite a bit for blasting when I was restoring my 1930 coupe but now has be used mostly just to top off tires as needed. I have no idea what the tank is made from or what it looks like on the inside. Should I be concerned?
 
To test your air tanks you use water and grease.

plug up everything and fill with water as best you can. Then plug the last hole with a grease fitting. Bring up to pressure with grease.

If the tank pops you just get a lot of water and grease, but no explosion.

For gross details look up how to pressure test a tank. It is out on the net in a bunch of places.
 
In 1988 my uncles father-in-law was killed when his compessor exploded in his shop. It was a large 1950's vintage compessor that had been rebuilt several times. He was a truck driver and most likely did not often drain the water from the tank. In my opinion tanks should be tested if it is over 10 years old. Better safe than dead. Rod
 
I wuz gonna' look up LBS, but the BIG dicshunary is clean across the room & I culdn't REACH it!
WHY?? duz my compotator keep underlining wurds with a JAGGED, RED line?? (The Dog's LAFFIN'!!!!)
Bill W.
 
I wrote a long reply about "hydrotesting" the tank but it disappeared just as I was about to post it. The bottom line is, if the tank does not have an ASTM stamp-tag, get rid of it.

Vic
 
My dad was a plumber and in '64 he stopped for gas at the service station next door to the shop. He told his helper to air up the portable tank they carried to test the potable water pipes in the new construction. Well the helper attached the hose to the tank and went in to gab with the owner and my dad came to the back of the truck to disconnect the hose just as the end of the tank blew out striking him in the face. The piece flew over the gas station, over the plumbing shop and landed about 250' away. My dad lost his right eye ,the hearing in his right ear, the left eye was damaged and he couldn't move the eye. His skull was crushed and after 2 months in a coma he did survive the explosion and numerous surgeries.
I won't use the air chucks that have the latches to hold onto the stems and every time I start a compressor I get an eerie feeling and remember my dad's terrible injury. Stuff happens. Check your equipment and destroy any tank you feel is unsafe.
 
See the picture in the link and read my first post below the picture.

http://www.fordbarn.com/forum/showthread.php?t=28419&highlight=proof+big+bang

Yesterday I drove 250 miles round trip to pick up this nice little antique air compressor. The gauges are the standard 2" size, so you can see how small the pump is. When I went to lift it, I was shocked at how heavy it is. The cast iron tank must be at least 1/2" thick.

Tonight I was just thinking, this is the first time I remember seeing a cast iron air tank. You can see it's embossed on the side of the tank "TESTED 300 LBS". I'm not worried about the tank blowing up, but if it did, I would imagine it would fragment like a hand grenade. Is it still legal to make tanks out of cast iron?:confused:

BTW, how did pounds come to be abbreviated "LBS" when there is no L nor B in the word pounds?:confused:
I don't see a safety blow off. That could be dangerous. JMO
 
The stamp you would be looking for is ASME with a cloverleaf around it. I doubt that a tank this old would have it. To properly test the tank first you determine the metal composition, checking the carbon content in the metal. next determine tensile. A formula can be used to convert brinnel to tensil. next UT the entire tank to determine the wall thickness, This will show any bad areas especially along the bottom where rust would start. Then using the UT numbers and tensil the working pressure can be determined, usually 150lbs but a safety factor of ASME 3.5 is added so the tank should calc at 525 lbs. If the math doesn't support this then it is condemed . remember the ends have to have UT. Once the tank is determined that it is safe, through math, that it is OK at 525 lbs then a hydro is performed. The tank is then hydro tested at 125% of MAWP or 187.5 lbs. Do not hydro anything above 125% as a hydro test is destructive in itself. A safety valve is only added insurance. If the math is not done then perhaps you are operating a pressure vessal at 150lbs and it may blow at 151lbs. A hand operated hydro pump can be rented. They are used in the plumbing industry to check new water lines in a house. be safe and buy a new tank, give this one to a museum.
 
I spoke to a customer service representative of Campbell Hausfeld and he said that even though my unit is old it has 3 built in features which would allow air to escape from the tank before it would rupture. Having said that I'm thinking that all these fail safe features are designed to prevent the tank from failure due to being overly filled not for failure due to the tank rusting out.
 
..... i might start to wonder why there is no "L" nor "B" in the word "Pound". :rolleyes:

From Chemistry.about.com

"Question: Why is lb the symbol for pounds?

Answer: Have you ever wondered why we use the symbol 'lb' for the 'pounds' unit? 'pound' is short for 'pound weight' which was libra pondo in Latin. The libra part meant both weight or balance scales. The Latin usage was shortened to libra, which naturally was abbreviated 'lb'. We adopted the pound part from pondo, yet kept the abbreviation for libra."


Und tomorrow Schtudents, ve gonna schtudy vhy de vord "ounce" ist abbrrrreviated mit der "oz".
 
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