# How Much Water Pressure Will a 55 Gallon Barrel Hold.



## Drizler

I am looking at a barrel fed solar batch heater to run into my oil boiler for summer useage. I have looked all over the net and find all sorts of warnings about city water pressure being too much but no actual figures. What I am looking for is something to take well pressure which is set at around 55 pis at the water tank. I doubt there will be over 40psi in the tank where I will be putting it outside so if it does pop its not such a big deal anyways. Any educated guesses what psi one will take before it pops? I just can't see an old hot water tank being much stronger than a sound drum.


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## pancho

Drizler said:


> I am looking at a barrel fed solar batch heater to run into my oil boiler for summer useage. I have looked all over the net and find all sorts of warnings about city water pressure being too much but no actual figures. What I am looking for is something to take well pressure which is set at around 55 pis at the water tank. I doubt there will be over 40psi in the tank where I will be putting it outside so if it does pop its not such a big deal anyways. Any educated guesses what psi one will take before it pops? I just can't see an old hot water tank being much stronger than a sound drum.


Check the thickness of the metal and the seams, quite a bit of difference.


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## Dahc

Drizler said:


> I am looking at a barrel fed solar batch heater to run into my oil boiler for summer useage. I have looked all over the net and find all sorts of warnings about city water pressure being too much but no actual figures. What I am looking for is something to take well pressure which is set at around 55 pis at the water tank. I doubt there will be over 40psi in the tank where I will be putting it outside so if it does pop its not such a big deal anyways. Any educated guesses what psi one will take before it pops? I just can't see an old hot water tank being much stronger than a sound drum.


I don't have any numbers for you but I'm pretty confident that a 55 gal air tight drum will hold 40psi. They store many things in these barrels that expand and contract with a lot more pressure than that.

I would weld a pressure release on it though if you're going to make hot water.


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## SolarGary

Hi,
We should start a pool 

I don't think it will hold 50 psi.
If the drum is 2 ft(?) in diameter, 50 psi is about 23,000 lbs acting on the top and bottom of the drum. The drum top and bottom are flat -- not really shaped to hold much pressure. I think the drums ends will first bulge out and then leak big time. But, I'm not sure. Pretty easy to try it.

Gary


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## Drizler

They also could be easy to reinforce. Me thinks I could lay some 1/4" rod across there in a few places to reinforce it. The ends of the barrel should be thick enough to weld on using my MIG with no problem. One of these days I will get a couple clean barrels and give it a crack. I have some nice ones for practicing but since they had gasoline in them last year I can't practice on those. :angel: Too bad real tanks are so ungodly expensive and so is copper or I would just make up some nice low profile boxes but not at those prices.


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## Jim-mi

A 50 gallon electric tank could well be cheaper than a trip to the horse-bittle . . . . .when the drum blows up. . . . . . .lol


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## ET1 SS

I get 55-gallon drum free at the local twinky factory.

If one will not hold the pressure; the next one will. 

I use them for a thermal-bank, in our radiant heating loop. Right now our system is set at 25 psi.

I have not had a leak yet.


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## MELOC

when i was a young and dumb pup, i had a job at a factory where i had to setup 55 gallons steel drums of liquid freon. this entailed removing the small bung screw and installing a threaded spigot. some bonehead filled one and left it in the non-climate controlled warehouse in the middle of summer. it was bulging a bit, but being young and dumb, i removed the bung anyhow. it shot past my face and nearly lodge in the ceiling panels of a 10+ foot high ceiling. i imagine that particular barrrel held a good deal of pressure.


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## wy_white_wolf

A better choice might be to search around for an old camp trailer that has an aluminum water tank. The ones that used air pressure to pump the water. These were build to handle the pressure and you don't have to worry about them rusting and contaminating you water.


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## Dave S.

20 psi will start to bulge the ends of the barrel, 40 will seriously distort it, and they let loose with catastrophic results at about a 100, this is for a really good barrel. They aren't meant to handle pressure, it is a bad idea. Any of the pressure experienced from heating and cooling is probably not more than ten psi. I have done destructive testing on barrels when I was developing an air powered transfer system to move glycol into cooling towers and found that the pressure needed to move the glycol 18 feet vertically was more than the barrel could handle.


Dave


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## rambler

Boom.

This is a really bad idea.

I'll leave it at that.

--->Paul


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## John Hill

A barrel filled with water under pressure is not really dangerous UNLESS the water is hot.

Just think on this a minute. For example, fill a barrel with water and fit a tyre valve then attach you hand pump and see how many strokes to get the pressure up, not very many at all.

Now do the same with an empty barrel, you would be pumping for hours to reach 40 psi.

The pressure in the barrel filled with water rose very quickly but the barrel filled with air took much longer to pressurise. The difference is the amount of work to raise the pressure and the work put in is related to the violence should the barrel burst.

In my opinion the risk of violence from bursting is related to the amount of compressed air, or gas of any kind, in the barrel when it pops. If the barrel is always filled to the brim with cold water there is little risk. I am not saying the barrel will take the pressure just that the consequence of a barrel failure will be little if the barrel contains incompressable water.


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## crafty2002

Dave S. said:


> 20 psi will start to bulge the ends of the barrel, 40 will seriously distort it, and they let loose with catastrophic results at about a 100, this is for a really good barrel. They aren't meant to handle pressure, it is a bad idea. Any of the pressure experienced from heating and cooling is probably not more than ten psi. I have done destructive testing on barrels when I was developing an air powered transfer system to move glycol into cooling towers and found that the pressure needed to move the glycol 18 feet vertically was more than the barrel could handle.
> Dave


That doesn't sound right Dave, unless the glycol weighs a lot more than the 8.34 Lbs. per gallon of fresh water. 
In a vertical rise of water there is only .43 PSI of pressure per foot, or 2.3 feet per one PSI., so that would only have been 7.74 PSI on the bottom of the barrel and about 6.45 PSI on the top of it. 

Drizler, you can get a small English Wheel and pan out some 3/32" sheet metal into a dome shape like air tanks etc., have and I would think the rolled rim on the barrel would be good enough for a small bead with the mig welder. 

On the other hand, you could give the guy at the dump a ten spot to keep his eye out for a large water heater coming through and yes, a hot water tank is about twice as think as a barrel, plus they already have a rounded top and bottom on them. 
Most of them are concave inwards at the bottom instead of outwards like the tops are but they still hold the pressure because of the dish shape. 
Plus you could get a tank that will hold more water also and you would already have a pop off valve, or atleast a location to put a new one. 
And you are correct John Hill. It would be dangerious if filled with air but a solid tank of water wouldn't suddenly expand very much incase of a rupture.
And last but not lest, drilzer, if the tank is level with your water supply, the pressure will be 55 PSI., at the supply tank also. If it is lower the pressure will be higher and if it is higher the pressure will be lower. 
Good luck.
Dennis


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## pancho

The liquid we use in our absorbers weigh a lot more than water. A barrel of it will weigh over 900lbs.


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## hunter63

rambler said:


> Boom.
> 
> This is a really bad idea.
> 
> I'll leave it at that.
> 
> --->Paul


I second that, pressure and steel drums not rated for it is bad business.


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