stacked storage tanks

[warno]

Below a picture of an ASME rated tank (section VIII) with flat bottoms (Hydronic Specialty Supply)
You can clearly see the stays, and there are many of them.

Those look like ends of rods that are welded into the tank. Do they run through the center to the other side? Either that or plug welds holding interior supports in. Either way nice looking tank.

 

[DaveBP]

I think this is about as close as you can get stacked 500 gallon tanks. Inside that skirt around the middle they are actually touching.
Just cleared the center beam in my basement by an inch. They fit nicely under my basement stairway.

 

[NP ALASKA]

Cool thanks
my thought was to weld 1" flat plate square
About 4" beyond the edge of the tank wall helping establish a good stable base

 

[NP ALASKA]

Ive seen these tanks before
very impressive
i do not want to stack 1000 gallon tanks as they will be very cumbersome to move
if i cut them ill have 4 500 gallon tanks to deal with

 

[PassionForFire&Water]

Those look like ends of rods that are welded into the tank. Do they run through the center to the other side? Either that or plug welds holding interior supports in. Either way nice looking tank.

These stays run from top to bottom

 

[warno]

That's what it looked like. Good design.

 

[Tennman]

A 42" dia 1" flat plate, simply supported, loaded to 30 psi (some safety factor) deflects ~.14" in the center. The plate weighs almost 400#. Not elegant but acceptable if welded correctly. I'd do full penetration to be safe.

A .5" plate deflects ~1.12" (pretty bad strain on the attachment weld). I think standard tank wall thickness is about 5/16" (.31).... that would be very bad without stiffeners. I ignored fluid weight.

It CAN be done..... but... The good thing is the explosive stored energy is very small so it's not really dangerous if it splits, just messy.

 

[Sid]

I stacked two 500 gal. One is on the floor and other is on stand. Have a 2 inch black union connecting them. Don't know how well it's gonna work but hope to fill the with water soon.

 

[Tennman]

Sid, Looks like your frame will do an efficient job of keeping tanks vertical. What supports the ~5,500 lbs per tank?

 

[Tennman]

LOL..... Sid, Just read your tanks are horizontal elsewhere.... Funny. That sure looks like a wall on the left above.

 

[NP ALASKA]

I stacked two 500 gal. One is on the floor and other is on stand. Have a 2 inch black union connecting them. Don't know how well it's gonna work but hope to fill the with water soon.View attachment 161957

My current storage is thd same as this, it works great.

 

[NP ALASKA]

These tanks are non-pressurized, correct?
This type of construction will not be able to hold 5 psi, unless there are some stays inside to keep it "flat"

I know I guy here in town with a 200 gallon rectangle tank he made out of 3/8 plate, it does have any reinforcement and is pressurized. Should he be concerned?

The side bulged a little I think, no worse that my aluminum fuel tank in my truck, of course it isn't pressurized.

 

[NP ALASKA]

I checked with my guy and he says the plates are reinforced with channel iron on the bottom . He also tests to 35 psi before the tanks are shipped. I usually run at around 20-22 psi max. Sorry, I forgot to ask how thick the plate was.

Do you have any PICs of the tanks during construction or before you installed them?

I am really trying to do this right and do not want to stack 1000 gallon tanks. the halves will be so much easier to move around and I think stratification will be better with vertical tanks like this. Yours perform pretty well don't they?

 

[Tennman]

I know I guy here in town with a 200 gallon rectangle tank he made out of 3/8 plate, it does have any reinforcement and is pressurized. Should he be concerned?

Concerned that it will fail.... most likely will eventually and make a big mess. Concerned that it will hurt someone.... hard to say. Our boilers are stiffened rectangular pressure vessels. But no professional in his right mind would do flat sided pressurized tank it unless someone did some math on the wall and weld stresses/deflections. Since water's incompressible not a huge amount of energy to send pieces flying when a weld lets go. He should at least skip weld some stiffeners to the outside. That's typical on big flat sided pressure vessels. The stiffeners should run up and down across both spans. Lots of work versus buying something round.

 

[Bob Rohr]

Here is an example of an EvoWorld pellet boiler being built In NY. It does take a lot of rods, closely spaced to build a flat, pressurized container. A lot more than I would have guessed. This is a 30 psi rated HX.

 

[tmudd]

I scored two 1000 gallon propane tanks for cheap.

Thinking about cutting them in half and welding plate in order to set them on end in new boiler room.

any thoughts on cutting them in half like this?

 

[NP ALASKA]

Ok so im approaching this from another angle

Are vertical tanks better than horizontal?

I may have a way to stack the 1000 fallon beasts but am more interested in approaching the design and effciency side of things.
I currently have stacked 500's
So there is no hurry

If the verticla is best as i think inhabe read many palces in stratification erc
I want to lookat this for sure

Any ideas on wether stacking would be less efficient than vertical
Regards

 

[maple1]

How do your 500s do?

My stacked 330s do great - I see 40° stratification all the time, and that's in only 5' of tank height (each tank is 2.5' diameter). Would depend on how much flow is going through them though when drawing from storage - I don't think my system draws much more than 5gpm.

I would go vertical if I could do it easily. Otherwise would not hesitate to stack.

 

[NP ALASKA]

My 500's do good
I want the additonal storage for my Alaskan home that see some real negative temperatures

I think i can do vertical if i can get tanks welded reasonably

 

[Tennman]

Look thru Siegenthaler's Training pdf in the top Sticky. Beginning about page 55 shows the physics advantage of vertical. The physics establishes that tall gives better thermocline. But I've never seen any data indicating what % performance benefit there is over being slightly shorter but much wider. I think 1000 gal tanks are the same diameter as 500s so obviously they would offer a significant thermocline advantage standing upright. In another publication somewhere I saw a very tall tank that I believe Siggy put in his own home. Looked like something from a refinery. So "best" for efficiency, physics says tall. On the practical side, Garns are horizontal as are most folks systems here because of height limits and the challenge of erecting them. Everyone here with stacked horizontals are very happy. So... do what you CAN do and you'll be happy. I chose vertical primarily because it offered me the smallest footprint and we had the ceiling height, so we got the best of both worlds. But I will emphasize, it is no small logistics feat to erect just 500 gal tanks inside a building. Also, its much simpler to weld legs to the outside for standing vertical, but sure not simpler to erect them. If you choose to go vertical I'll be glad to calculate the angle size, weld length, and weld fillet size for your legs if you don't have anyone to do that. That is critical from a safety standpoint. And you must consider if your slab can take the more concentrated loads of vertical tanks. Can't help there. Standing up a 1000 gal tank would take some serious equipment and planning. BTW, after we did the welding the next stop was the foamer before coming to the house. You get a bou or moose this year?

 

[DaveBP]

The thermocline in these tanks is never perfect. There is always a band of water that is some mix of hottest-to-coolest and on a horizontal tank that mixed zone is over a larger area and therefore makes a larger volume of water that is not as hot as that ideal stuff above it.

I think if you're using radiant floors or panels that can efficiently use lower temperature water that volume of 'compromised' water will still be useful. If you have a more typical baseboard setup, on those coldest nights that mixed water may not be so helpful.

I don't think it's a matter of efficiency so much as that a horizontal tank will have a marginally lower capacity for useful heat in some setups. It's that convenience thing again. Might be able to stay in bed a little longer on those coldest mornings before having to run down to fire the boiler again.

How long? 5 minutes? 20 minutes? Where's Eliot? He could put credible numbers to the difference.

 

[ewdudley]

I don't think it's a matter of efficiency so much as that a horizontal tank will have a marginally lower capacity for useful heat in some setups. It's that convenience thing again. Might be able to stay in bed a little longer on those coldest mornings before having to run down to fire the boiler again.

I recall in high school our physics teacher set up an aquarium half full with red-dyed hot water and then gently piped in some blue-dyed cold water in the bottom. The layer of purple water was only a couple two three centimeters thick when all was said and done. And surfacing slowly in a quarry your ears can be warm when your neck is still cold.

Stratification is easy in the case of heat storage from boilers because the supply temperature is reasonably constant and the relative buoyancy across the thermocline is large. The hard cases are: solar heat storage where the supply temperature can vary a lot and it is very difficult to get the water to diffuse at the proper elevation; and chilled water storage, where, although the supply temperature is constant, the difference in density between 32F and 60F water is only about 1/20th the difference in density between 90F and 170F water.

So as Dave points out, the only disadvantage of horizontal is the larger amount of mixed water at the thermocline, so the supply of nice not water will start to peter out sooner. You still get as much heat out as you put in (give or take differences in standby losses), so the only real difference is that you can store somewhat more heat between firings with vertical as opposed to horizontal tanks, of the same volume.

So vertical may offer some minor thermal storage capacity advantage, but typically it is a moot question since vertical is not an option to begin with.

 

[NP ALASKA]

Look thru Siegenthaler's Training pdf in the top Sticky. Beginning about page 55 shows the physics advantage of vertical. The physics establishes that tall gives better thermocline. But I've never seen any data indicating what % performance benefit there is over being slightly shorter but much wider. I think 1000 gal tanks are the same diameter as 500s so obviously they would offer a significant thermocline advantage standing upright. In another publication somewhere I saw a very tall tank that I believe Siggy put in his own home. Looked like something from a refinery. So "best" for efficiency, physics says tall. On the practical side, Garns are horizontal as are most folks systems here because of height limits and the challenge of erecting them. Everyone here with stacked horizontals are very happy. So... do what you CAN do and you'll be happy. I chose vertical primarily because it offered me the smallest footprint and we had the ceiling height, so we got the best of both worlds. But I will emphasize, it is no small logistics feat to erect just 500 gal tanks inside a building. Also, its much simpler to weld legs to the outside for standing vertical, but sure not simpler to erect them. If you choose to go vertical I'll be glad to calculate the angle size, weld length, and weld fillet size for your legs if you don't have anyone to do that. That is critical from a safety standpoint. And you must consider if your slab can take the more concentrated loads of vertical tanks. Can't help there. Standing up a 1000 gal tank would take some serious equipment and planning. BTW, after we did the welding the next stop was the foamer before coming to the house. You get a bou or moose this year?

Thanks, great things to think about.
As for the moose, hows this one look

 

[NP ALASKA]

So, in my case vertical is an option

I just have to modify the tanks

I dont even want to look at stand a 1000 gal tank on end

The idea is cool, but building a building for it is crazy talk

I am building a 3 rd garage bay that will be used to house my boiler and tanks, just wont be enough for standing these beasts on end as is

I am planning for a real good footer with 10" of crete where tanks will sit

 

[Tennman]

Exactly, the idea is cool, but....

I'd enjoy a moose story, but might get shut down. Huge!