Compressor Tank Advice

[motox101]

I purchased a 80 Gallon Horizontial 200psi mx, 5hp motor. I brought the compressor home and decided to hydrostatic test it after reading on this site how easily you could do it. I got it to hold 300 psi for 45 mins. I did notice that it had been welded by the previous owner which was not disclosed to me. at 300psi there was a small drip of water out of the center of the weld. the inside of the tank looked great but I only gave it a quick look. needless to say the weld job looked like somebody who is inexperienced.

My questions:

1. should I use this tank as is
2. could I have that area patched correctly?

 

[ezover]

I would replace the tank. they are cheap enough on craigs list. you tube exploding air compressors tanks and that should be enough to convince you to replace yours.

I have not looked in a couple of years but I recall 80gal. tanks going for 100.00 give or take.

 

[bad_idea]

scrap it.

 

[sberry]

Too much a booger for a comp tank. They should look like this, second pic was a test with a stop in middle to change 1 volt to try to reduce some splatter.

 

[Greyhorse]

The "weld" on that tank looks awful, I wouldn't trust it.

 

[motox101]

Yes guys I know the welds look awful

Can a professional welder salvage this? Grinding it flat and then putting a plate over it?? It held 300 psi with no leaks

 

[The Tool Tyrant]

You can visually see cracks propagating in the weld. Don't use it for a pressure vessel.

Suggestion: cut in in half and make a smoker out of it!

 

[sberry]

It could be but finding someone qualidied who is willing to do it may be a problem.

 

[Thedave1164]

Cost/Benefit

Don't bother, you could find a used tank for about the same money it would take to properly fix that one.

And even fixed, I still would not trust it

 

[PT Doc]

Seems reasonable to stick weld a leaking pressure vessel. Who needs to be certified to do welding when you have welded numerous things in your shop with a stick welder?

Cut the tank open and use it as a planter. That is the only reasonable use for this at this point if you value your health and safety and that of anyone else living in your home.

 

[kbs2244]

If you decide to use it go to the local hot rod shop and get a "trans blanket" to wrap around it
They use them at drag strips to contain the pieces when a transmission blows up.

 

[sberry]

The likelihood of it blowing up is pretty remote. It has happened but I never seen one, don't know anyone it had happened to. For every one of those 50 thousand die in cars, not sure of the exact number but it's pretty rare. Again since someone missed it, it has happened. I fixed one of my portables a while back, ****** factory weld on an axle bracket. It was obviously good enough to leave the factory.

 

[rsanter]

Where are you going to put it?
If you put it outside I might use it.
I would first look to see what a new tank would cost then go from there

Bob

 

[Richard Cranium]

no way would I put it in my shop, I like my stuff too well.

 

[Lwel9226]

Scrappit

LynnW

 

[joe49]

I purchased a 80 Gallon Horizontial 200psi mx, 5hp motor. I brought the compressor home and decided to hydrostatic test it after reading on this site how easily you could do it. I got it to hold 300 psi for 45 mins. I did notice that it had been welded by the previous owner which was not disclosed to me. at 300psi there was a small drip of water out of the center of the weld. the inside of the tank looked great but I only gave it a quick look. needless to say the weld job looked like somebody who is inexperienced.

My questions:

1. should I use this tank as is
2. could I have that area patched correctly?

1] No

2] Yes most of the time. But cost will likely favor a new replacement.

 

[rustyjames]

Seems reasonable to stick weld a leaking pressure vessel.

I can tell you that stick welding pressure vessels is an acceptable method of repairing a pressure vessel.

 

[American Locomotive]

You can possibly try contacting a local boiler repair shop (we're talking big boilers here) - they might have someone certified to weld & repair pressure vessels.

I would not use that tank as is.

 

[dr_clyde]

That tank is no good as is. That weld is already cracked. I would not use it as is. If the rest of the tank is in good shape, it might be worth fixing.

You're gonna want to find someone who is certified to ASME section 9, the welding code for boilers and pressure vessels. Expect to pay probably $100 minimum for the weld, probably more like $200. If you modify a pressure vessel, it will need to be re-tested and re-stamped to code before they'll let it out of their shop.

If I had that welding ticket and you were a friend, I'd charge you $150 cash for a welded patch as a moonlight job, no paperwork or check. I probably wouldn't do it at all for a stranger.

Welding gets funny when pressure vessels are involved. All of a sudden things like testing and welder qualification become really important.

 

[Rock knocker]

You can possibly try contacting a local boiler repair shop (we're talking big boilers here) - they might have someone certified to weld & repair pressure vessels

I'm sure they do, what kills that idea is the cost of three or four hours of welding time, then doing the hydro test with Hartford Steam Boiler on site to observe. And depending on the state, they might want to sign off too.

 

[Rock knocker]

You're gonna want to find someone who is certified to ASME section 9, the welding code for boilers and pressure vessels. Expect to pay probably $100 minimum for the weld, probably more like $200. If you modify a pressure vessel, it will need to be re-tested and re-stamped to code before they'll let it out of their shop

I think a shop will need a hydro test and Hartford on site no matter what

 

[Zeke]

If you decide to use it go to the local hot rod shop and get a "trans blanket" to wrap around it
They use them at drag strips to contain the pieces when a transmission blows up.

The tank would likely rip the blanket to shreds. That tank is dangerous and it's total scrap, but you knew that and were making a joke (I think).

 

[Snip]

My opinion would be to replace the tank. Not that a safe repair couldn't be done but the underlieing question is what is the condition of the rest of the inside of the tank? Also is there much of a cost savings repair vs new? In all reality if a repair costs 200 and a all new steel (tested and certified to boot) tank costs 300. the new tank only costs you 100 because you are spending the first 200 either way.
Besides the old tank has the makings of a great start for a nice smoker! That in itself would be worth the 100 dollar difference.

 

[FTG-05]

Since you can hydro it yourself - and you want to use it for yourself, I would be inclined to repair it.

Grind out the old welds; reweld the cracks; grind those welds down and weld an oval 12-10 ga steel patch over the whole area.

And then rehydro at 325 psi - 5 times.

But that's me.

Good luck with whatever you do.

 

[malibu101]

Since you can hydro it yourself - and you want to use it for yourself, I would be inclined to repair it.

Grind out the old welds; reweld the cracks; grind those welds down and weld an oval 12-10 ga steel patch over the whole area.

And then rehydro at 325 psi - 5 times.

But that's me.

Good luck with whatever you do.

I don't know,but, that may be setting up for failure.

The tank plate normally lists the maximum PSI at a certain temperature.
Pushing the pressure vessel beyond it's rated pressure is probably not a good thing.
Granted it CAN handle more than the max PSI on the plate. BUT how much more until it's stressed and may break at any time.
Breaks of a pneumatic pressure vessel can be very violent.
I personally have a great amount of respect for pressure in anything.

 

[pstnbly]

Since you can hydro it yourself - and you want to use it for yourself, I would be inclined to repair it.

Grind out the old welds; reweld the cracks; grind those welds down and weld an oval 12-10 ga steel patch over the whole area.

And then rehydro at 325 psi - 5 times.

But that's me.

Good luck with whatever you do.

Don't even think of doing this! The HAZ of the previous weld has already work hardened that area of the tank. Gouging it out and re-welding will further work harden the area. What are you planning to use for a filler? What about hydrogen embrittlement? Do you materials engineer or qualified welding engineer to consult?

This is insane. On a forum that will use up 5 pages of comments shredding someone for even joking about PVC airlines we have members giving advice about welding on a pressure vessel with a failed previous cobb weld. There is exponentially more stored kinetic energy in that tank then could ever be in a PVC airline.

THAT TANK IS DONE, DESTROY IT, YES I AM YELLING.

 

[brianh]

I'm sure they do, what kills that idea is the cost of three or four hours of welding time, then doing the hydro test with Hartford Steam Boiler on site to observe. And depending on the state, they might want to sign off too.

3-4 hours welding time?...................

 

[Rock knocker]

3-4 hours welding time?...................

Find a procedure, prep, find heat numbers for repair plates as needed, order new steel with heat numbers intact, contact engineer, contact Hartford, weld.

See, it adds up.

 

[Zeke]

My opinion would be to replace the tank. Not that a safe repair couldn't be done but the underlieing question is what is the condition of the rest of the inside of the tank? Also is there much of a cost savings repair vs new? In all reality if a repair costs 200 and a all new steel (tested and certified to boot) tank costs 300. the new tank only costs you 100 because you are spending the first 200 either way.
Besides the old tank has the makings of a great start for a nice smoker! That in itself would be worth the 100 dollar difference.

You and my wife think the same way.

 

[Rock knocker]

No way would a ASME shop repair that for $200.

When I worked for a ASME "R", "U", "P" and "A" shop, we were called all the time to repair small tanks. Our mobilization costs normally exceeded what a new would cost from Graingers, much less than the added costs of engineering, Hartford, material tracking, chemistry and procedures.

 

[FTG-05]

Don't even think of doing this! The HAZ of the previous weld has already work hardened that area of the tank. Gouging it out and re-welding will further work harden the area. What are you planning to use for a filler? What about hydrogen embrittlement? Do you materials engineer or qualified welding engineer to consult?

This is insane. On a forum that will use up 5 pages of comments shredding someone for even joking about PVC airlines we have members giving advice about welding on a pressure vessel with a failed previous cobb weld. There is exponentially more stored kinetic energy in that tank then could ever be in a PVC airline.

THAT TANK IS DONE, DESTROY IT, YES I AM YELLING.

So, you're saying using PVC is ok for compressed air lines?

OK.

















I'm just messin' with you. No need for more BP medicine. Take a deep breath.


And now since we've taken care of the tank issue: I'd like to hear more about this easy way to hydro test tanks bidness.

 

[MoonRise]

My questions:

1. should I use this tank as is
2. could I have that area patched correctly?

1> NO !!!!

2> Not realistically.

Turn that former pressure vessel tank into anything other than a pressure vessel. Turn it into yard art, a planter, a livestock (small livestock, anyway) watering tank, a BBQ or smoker.

It is no longer safe as a pressure vessel.

Because it was half-a$$ welded, it is now pretty much either scrap or turn it into a non-pressure-vessel use.

Just go and get a new replacement 80 gallon compressor tank.

 

[Spareparts]

Ask your Insurance Man and see how loud he yell's NO, seriosly if something goes wrong with a modified tank you will be on your own.

 

[sberry]

They insure motorcycles which if we're invented today wouldn't be allowed on the road.

 

[motox101]

Thanks for all the replies. If someone could point me where I can find an 80 gallon pressure tank for 300 bucks that would be great!

 

[Rock knocker]

This looks pretty good, the "U" cert seems legit.

http://www.ebay.com/itm/Steel-Fab-1...PSI-Air-Compressor-Tank-Yr-2008-/352126220915

 

[Stuart in MN]

Youtuber Tubalcane did an autopsy on an old leaking air compressor tank, it's an interesting video:

You can see how thin the metal around the pinhole leak has become, and also that the only way to really tell how much of it is damaged to cut the tank open.

I have seen the aftermath of a small compressor tank failure in a residential garage - the tank was turned inside out, it looked like a big metal potato chip. The car parked next to it didn't fare so well.

 

[Michael_in_DE]

Weakness in one spot is indicitave of a wider problem. it didn't rust in just that one spot. The area is weak, and that is just where it got weakest. Sorry friend, I think your tank is hosed.

 

[motox101]

Found an ingersoll rand t30 tank for 150 bucks. Almost mint condition

 

[motox101]

Here's a pic