Zero Tank

[K.I. Joe]

I have the opportunity to get a commercial compressor tank about six feet high and about three foot in diameter. I was thinking of using it as a zero tank at my pumphouse. Do you think that the tank would crumble under vacuum or would it withstand the force.

[Cedar Eater]

I'm not an expert in the vacuum systems used for sap, but pressure vessels that can't tolerate a negative 14.7 psig pressure differential are pretty rare. Some seals only seal against positive pressure differentials, but I'm assuming this tank just has threaded pipe fittings and those should be fine.

[markct]

I would be more worried about sap in a rusty oily air comp tank ick.

[maple flats]

I wouldn't trust it. A zero vacuum tank is labeled as such and they are tested when new at 20" vacuum. I have an older vacuum tank and run it at 19" without issue, but a tank designed for pressure is not designed to hold up to vacuum. Even a modest vacuum has tons of crushing force on it from the air pressure. If my quick math in my heat is close, at 14" vacuum, you will have over 7 pounds of pressure on every sq. inch. if you take just 1 sq. foot, that would be over 1000# crushing force on every sq. foot. (7x144)
It might be a quick way to get a load of scrap metal to fit in your truck better for a trip to the scrap yard.

[BreezyHill]

I have the opportunity to get a commercial compressor tank about six feet high and about three foot in diameter. I was thinking of using it as a zero tank at my pumphouse. Do you think that the tank would crumble under vacuum or would it withstand the force.

No, no, no. That is a disaster waiting to happen.

Compressors have a special oil that impregnates the steel and is why they tanks last as long as they do without rusting away from the condensation they produce all the time.
They are designed to not explode...vacuum is totally different...think of a beer can it can withstand quite a bit of pressure but put a little vacuum on it and it crumples...like a beer can.

IF you are lucky when she does crush it is with no pieces coming off. Saw a dairy balance tank missing a piece after it failed.

Zero tanks are great tools...my dad sold them. The older ones are the best cause the company went bankrupt and started using thinner metal and had several failures that led to the being bought up by another company. The redesigned tanks were much better but came with a tag stating 20" max. Many systems washed and rinsed at higher vac levels than the 15" for milking; before air injection became the standard practice. Some new systems on VFDs still use higher vac to was again.

I have an older style and we ran her at 26-28" for years with no issues. Now she is just a storage tank.

I applaud your imitative, but I strongly suggest you don't do it.

[WESTMAPLES]

huh i must be crazy then i have in use 2- i believe 42 gallon john wood air tanks that are tested for 300 psi at 100 degrees. they came with 2 gast vac pumps bolted together with matching paint i bought before last season, so i figured that they where designed into another system that way before.... so i used them for balance tank/ moisture trap had both of them all the way to the 26 inches the gast pumps will pull and haven`t had a problem yet. im not saying use it ive also imploded a 55 gal steel drum with the same pump and balance tank just for a drinkin haha and it was shocking in a hurry for sure be careful

[K.I. Joe]

It sounds like it may implode, thats too bad. Mark this would be between the releaser and the vac pump so no worries about sap in there but it sounds like I should not waste my time. Thanks guys

[markct]

Thats a balance tank or vac resevoir then rather than a zero tank. I doubt it would implode realy

[WESTMAPLES]

honestly i would hook it up and take it to max vac and see what it does but be ready for the worst i wouldn`t lose any sleep over it, thinking its going to blowup like things in the movies, at worst it would end up taking up less space in your next scrap load !!

[K.I. Joe]

Dont want to spend the money getting it home and out in the woods only to see it implode