Air Tank Replacement?

[justin1]

I’ll repeat a quote from on of my welding instructors…”Don’t weld on pressure vessels unless you are qualified or brave.”

Fair I would say the avg DIY guy probly shouldn't. Really depends on OPs welding abilities. And if they copy layout of original tank they can avoid some issues. Just don't weld fittings on welded seams and avoid the radius of the bulk head aswell pretty much everywhere else is fair game.

Also space fittings atleast 2" apart ideally.

Non commercial air tanks are not the best welded things to start with aslong as they pass hydro they are sent out the door. They are not 100% penetration welded and just lap welded bulkheads but so are propane tanks generally.

If you have are going to tackle making you own tank feel free to ask me questions I would say send me pictures of you welds/ what machine you plan on using before proceeding and I'll be able to figure out if you should or shouldn't lol.

I happen to be pipe welder and do industrial vessel repair. If I were closer I would offer to do the welding once all the fit up was done as a air compressor that size is less then 1 hr of welding and 4 ish hours of fitting with new fittings if your reclaiming fittings probly be a weekend project.

 

[verbotenwhisky]

I have this rather old Quincy I bought. There are some serious looking patches. You can see the ~5x5 square welded in. Should I just buy a new tank and swap it out? I’ve heard horror stories of these things blowing up where they rust through.

Also I can’t find any information on this online and I called Quincy and they weren’t helpful. I’d like a manual or something.

Hydrotest to 1.5X operating pressure (typical test), that'll keep you below the safety and high enough to proof the tank for safe operation.

 

[verbotenwhisky]

I’ll repeat a quote from on of my welding instructors…”Don’t weld on pressure vessels unless you are qualified or brave.”

You do not weld on a U-stamped vessel unless you are an ASME shop with an R stamp cert unless you are very wealthy because your insurance will not pay for the damage when it takes out the corner of your garage. Welding is not allowed on DOT vessels post manufacturing and your home owners policy will likely be cancel if your insurance company finds a mil-spec vessel in the garage in use. There are a number of companies that sell those little receivers (note smaller than 500 gallons is smaller) at reasonable prices.

 

[justin1]

At a minimum don't run that tank it's no good, which ever direction you choose to go that current tank is a hazard.

Unless your using your compressor in a commerical application the DOT and ASME stuff doesn't really apply for home use aslong as your not trying to make and sell tanks, that kinda gets in a legal danger zone.

As far as insurance that's probly policy dependant and I'm sure there is a blanket term somewhere on all policies that they can blame tank explosion on gross negligence or some other shady way they can avoid having to help you.

When you buy a new compressor 3hp and below there is generally no U stamp on em unless they are marketed for commercial use. All air compressor tanks I know of have a expiry date of 10 years from manufacturer usually is on a sticker that is easily removed or written in the manual somewhere. Most tanks I've owned don't even have manufacture date on them so you have to hope the serial has a date code if it wasn't also on one of those easily removable stickers.

So technically anyone who has a compressor in there garage that is 10 years old or older is no longer "save to use" without professional recertification. Also if you have no way to figure out date of manufacture then it's automatically assumed expired.

In the end the easiest and safest thing to do would be buy new tank or salvage and hydro a good used tank. They do come up for sale on marketplace fairly often were someone burnt out a motor or compressor head. I would scope a used tank before commiting to buy as some people have no issue selling a rusted out tank.

And if your feeling adventurous make one there is ways to build a storage air tank system with stand alone compressor head that requires no welding just don't forgot a pressure relief valve and a way to drain water from tank so flip propane tank upsidedown and use a tee to make a low point. I would probly look into that route before modifying a tank and maybe save tank manufacturing as a last resort.

 

[verbotenwhisky]

At a minimum don't run that tank it's no good, which ever direction you choose to go that current tank is a hazard.

Unless your using your compressor in a commerical application the DOT and ASME stuff doesn't really apply for home use aslong as your not trying to make and sell tanks, that kinda gets in a legal danger zone.

As far as insurance that's probly policy dependant and I'm sure there is a blanket term somewhere on all policies that they can blame tank explosion on gross negligence or some other shady way they can avoid having to help you.

When you buy a new compressor 3hp and below there is generally no U stamp on em unless they are marketed for commercial use. All air compressor tanks I know of have a expiry date of 10 years from manufacturer usually is on a sticker that is easily removed or written in the manual somewhere. Most tanks I've owned don't even have manufacture date on them so you have to hope the serial has a date code if it wasn't also on one of those easily removable stickers.

So technically anyone who has a compressor in there garage that is 10 years old or older is no longer "save to use" without professional recertification. Also if you have no way to figure out date of manufacture then it's automatically assumed expired.

In the end the easiest and safest thing to do would be buy new tank or salvage and hydro a good used tank. They do come up for sale on marketplace fairly often were someone burnt out a motor or compressor head. I would scope a used tank before commiting to buy as some people have no issue selling a rusted out tank.

And if your feeling adventurous make one there is ways to build a storage air tank system with stand alone compressor head that requires no welding just don't forgot a pressure relief valve and a way to drain water from tank so flip propane tank upsidedown and use a tee to make a low point. I would probly look into that route before modifying a tank and maybe save tank manufacturing as a last resort.

If it is an ASME vessel it has no expiration and should have a tag or a MFG. serial number that can be traced back to the certification, I am fairly certain my frankincompressors tank has one and the maintenance and test regime is dependent upon your states laws or your own judgement. A DOT Vessel of any type is required to be recertified every 5 years and the numbers will be stamped into the vessel, with that said if you have an oxygen bottle (welding cylinder) setting in your shop that has been there for 10 years don't panic, it will be recertified when you exchange is, if its over 15 years it'll cost you a few extra bucks. I live in the world of pressure vessels they are a component of piping systems which is what I do, any commercial shop building pressure vessels for compressed fluid service (air is a compressible fluid) will have an ASME and/or DOT certification and build accordingly to avoid liabilities and law suits, its an insurance thing.