Pressurized RO Storage

[mudder]

Hello,
I am looking for reasons that this will not work, or threads where someone has tried this.
I have a 100gpd RO-DI unit with a 3g. pressure-storage tank, I use the water for drinking & cooking as well as my tanks. Problem is sometimes I need 30-40 gallons NOW. My idea is to tee into the line going to the existing pressure tank and run it to a clean, sealed 55g. drum. This should allow a much larger volume of water. The other thing I am looking for is a "formula" to figure the space, volume of air at different pressures. Example, 1 cubic foot of air at "0" guage pressure takes up more space than that same 1 cubic foot of air when compressed to 30-40psi.Is thier any formula to calculate what the space would be at different pressures.
Thank You All

[sphelps]

That won't work! The pressurized tank that was included with you RO unit has a type of bladder that acts like a ballon, when water is pushed in the bladder expands, and when water is removed the bladder contracts. This bladder will contain no air, just water, the water is pushed out of the bladder from the force made from stretching the bladder to size.

The best solution would be to add an "open" container using a simple flow valve which is available many places.

Your idea will work in the way of filling the drum, but the pressure created from the compressed air will not be enough to remove all the water, you'll probably be able to remove 2-3 gallons with that pressure build up. There's some easy calculations to figure out exactly how much will be able to be removed but it's not even worth the time. Trust me this won't work.

[cres]

PV=NRT

(insert explanation)
(skip to bottom line)

The barrel wil start (empty of water at atmospheric pressure) at about 15 PSI. If you then 1/2 fill the tank with water and let no air escape, the pressure will double to 30 PSI (take away the atmospheric pressure on the outside of the tank and you are left with 15 PSI on the guage.

If you 3/4 fill the bucket, you will have 60-15=45 PSI.

If you 7/8 fill the bucket, you will have 90-15=75 PSI.

You should draw the water from near the bottom of the tank so you don't remove any air.

Note, you will also not be able to exceed the line pressure feeding the RO/DI tank, it will shut down somewhat below this.

Actually it will work, (this is how the older well pump reservoirs worked) but, generally it is harder to seal the top of the tank. The air blatter makes it easier to start with pressure above atmospheric so when you start adding water, it is already presurized. You can almost never get the last 1/4 of the tank emptied without the blatter (the pressure drops too far to move the water).

If you do presurize the tank, there is a good chance that if the tank empties you will blow air into the line.

Hope this helps.

[hllywd]

Get a larger pressure tank, no need to reinvent the wheel....
:cool:

[mudder]

hllywd #1 reason cost 300.00 to 500.00 for a55g. tank
#2 This is the DIY forum.
cres
Those numbers are what I was coming up with, just wanted to make sure my logic made sense to someone else. I figured I can have "extra" drums for nothing but space for air to compress into. Naturally, water in & out of the bottom and the air line connecting, thru the tops. As far as sealing the drums that's no problem I have 2 piped into my tank system, between the display tank and the sump, it actually gives me an extra 120g. of water cruising thru the system. I can't remember the site but they had all types of fittings to adapt drum fittings to NPT fittings.
Thanks for your reply
Ed

[BeanAnimal]

Also 55 gallon drums have a very low burst pressure. Even at low pressure the severely deform.


here is a page with "bladder tanks"
http://www.watertanks.com/category/48/

You can find dozens of manufacturers of these products in just about any size you would ever want.

Sphelps, it kind works that way but you have it kind of backwards. The bladder contains air, and sits inside the shell. The water is pushed into the shell against the bladder. Th ewater is not pushed into the bladder, the resulting pressure would simply be the elasticity of the bladder pushing back.

The only purpose hte bladder serves is to keep the air and water seperate. When the shell is empty, so is the bladder. You do get all of the water out of the tank (well depending on atmospheric pressure).

Bean

Bean

[hllywd]

<a href=showthread.php?s=&postid=7017430#post7017430 target=_blank>Originally posted</a> by mudder
hllywd #1 reason cost 300.00 to 500.00 for a55g. tank
#2 This is the DIY forum.
cres
Those numbers are what I was coming up with, just wanted to make sure my logic made sense to someone else. I figured I can have "extra" drums for nothing but space for air to compress into. Naturally, water in & out of the bottom and the air line connecting, thru the tops. As far as sealing the drums that's no problem I have 2 piped into my tank system, between the display tank and the sump, it actually gives me an extra 120g. of water cruising thru the system. I can't remember the site but they had all types of fittings to adapt drum fittings to NPT fittings.
Thanks for your reply
Ed

1.) It's not safe. A 2 1/2" bung let's go @ 50psi it will do some real damage. Storage drums are not meant to be pressurized. 2.) Why do you need 55 gallons?

[Kent E]

buy one.

[cres]

You will have to check the specs for the specific barrel you have or get.

I saw some barrels listed at 150 PSI, others at 100, I'm sure others are lower. For example this one:
http://www.globalindustrial.com/gcs/product/productInfo.web?&infoParam.itemKey=30047795&infoParam.picGroupKey=3021
You will see the UN Rating as 1H1/Y1.9/150 (which indicates that the barrel can support matterials with a specific gravity up to 1.9 and has a rated pressure of 150 PSI.

The static water pressure of water in a container like that would be well under 2 PSI.

Having said all that, I would also endorse simply installing a pump to push the water out rather than pressurize 40 odd gallons of water.


If you install a bulkhead, make sure it can handle the pressure too.

[kysmith]

find an old water heater those things are good for a lot of pressure. I have a friend who uses one to store CO2.

http://www.brewboard.com/index.php?showtopic=7848&hl=

it's a beast of a thread and starts out with a lot of fart jokes but if you read on you will find he does it using an old hot water heater.

[rutledgek]

Juse put a float valve on the drum. No need for pressure and you always have your water available for the tanks.

[AZDesertRat]

You are creating a death trap, drums are not designed to contain pressure. If the top blew off the barrel at even 1 psi above normal it could kill you and that is a well documented fact that is taught in OSHA safety programs. If you want pressure get a larger pressure tank or possibly a legally obtained stainless steel beer keg or two. Pressure tanks are not that expensive at well, pump or plumbing supply stores.

[douggiestyle]

they also sell large pressure tanks at lowes.

[BeanAnimal]

<a href=showthread.php?s=&postid=7023629#post7023629 target=_blank>Originally posted</a> by AZDesertRat
You are creating a death trap, drums are not designed to contain pressure. If the top blew off the barrel at even 1 psi above normal it could kill you and that is a well documented fact that is taught in OSHA safety programs. If you want pressure get a larger pressure tank or possibly a legally obtained stainless steel beer keg or two. Pressure tanks are not that expensive at well, pump or plumbing supply stores.

I have seen several drums explode over the years, one severely hurting a fellow coal miner. Just buy the proper size bladder tank and you will save yourself a lot of trouble and headache.

[Roland Jacques]

Bean, i tried to pm you, but your pm is full.

[BeanAnimal]

hrmm

They must have shrunk the size of hte PM boxes, because I just deleted a ton of stuff.

Bean

[BMitch]

<a href=showthread.php?s=&postid=7028125#post7028125 target=_blank>Originally posted</a> by BeanAnimal
They must have shrunk the size of hte PM boxes, because I just deleted a ton of stuff.

You have to delete your Sent Items too. They affect your PM box count.

[BeanAnimal]

Yup.. But like I said, after a pretty good house cleaning, people still tell me it's full.

Am I blind, or is there no "mailbox quota" indicator.