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PVC Pipe as a tank

PostPosted: Wed Mar 06, 2013 5:14 pm
by RandyG
I was deciding how to store water without taking too much space a thought it would be a good idea if I used 3"-4" pvc pipe as a water storage tank. I would use the lead-safe pvc so we could drink it if needed. And I figure with some 90's I could get about 2 10ft of lengths inside my frame. That would be over 20 gallons or so.
Also, I thought about pumping air into the pipe (not much, maybe 20psi or so) to get it pressurized then I wouldn't need a water pump. 12v air compressors are pretty cheap. Any thoughts? Concerns?

Re: PVC Pipe as a tank

PostPosted: Wed Mar 06, 2013 7:56 pm
by droid_ca
I had started a few threads about building with PVC as I'd like to have some hidden water lines within my walls and roof to help keep the weight down as well as being a place to store water when not on the move

Re: PVC Pipe as a tank

PostPosted: Wed Mar 06, 2013 8:55 pm
by Bogo
Make sure you get drinking water safe PVC pipe. I forget which ones are drinking water safe. Some of the larger ones aren't.

Make sure the air pump is oil-less.

Consider schedule 20 6" pipe.

I'd mount side to side rather than front/back. When mounted front/back, the water will rush to the low end making it heavier. That will change the trailer balance allot. Mounting side to side, you can mount ones in front and behind the axle and the balance won't change. Fittings will be a cost issue. You'll have to find appropriate tank fittings. The end caps are about the only place you can easily mount commonly available fittings.

With built in tanks, you only want to fill them with clean filtered water. If you let any old water in, you could end up with a nightmare. A city supply likely wouldn't need filtering, but many remote campground water supplies are direct from the ground.

Re: PVC Pipe as a tank

PostPosted: Thu Mar 07, 2013 11:13 am
by pappaw
Does anyone know the formula to calculate a size pipe by the length to get the gallons it would hold? :thinking:

Re: PVC Pipe as a tank

PostPosted: Thu Mar 07, 2013 3:50 pm
by lancew
becareful Randy. 20 psi is a lot of pressure for water. using a small compressor is my plan. using a regulator with only 3-4 pounds of air.

Re: PVC Pipe as a tank

PostPosted: Thu Mar 07, 2013 4:31 pm
by RandyG
lancew wrote:becareful Randy. 20 psi is a lot of pressure for water. using a small compressor is my plan. using a regulator with only 3-4 pounds of air.

I was going to tinker with pressure before installing it.
And the way my trailer is built, 3" pipe will fit just right. I wasn't going to use straight pipe with end caps, I was planning on 2 loops to fit in the voids of my frame with a "T" pointing up to connect a hose and fill. It's alot to think about, I'm better at thinking as I build. Trial & Error! Thanks for the advice everyone.

Re: PVC Pipe as a tank

PostPosted: Thu Mar 07, 2013 8:36 pm
by coop74
just my two cents worth...

Mount your pipes vertically and join them near the the bottom . Make your water take off fitting near the bottom (but not directly at the bottom)so you get the pressure that results from the column of water as well as the air you introduce into the system. Being vertical you will not have to worry about it moving fore and aft or side to side. as the level goes down the relative change in weight will remain in the same spot. On the very bottom put another larger valve to remove sediment if it occurs in your system.

Just my two cents

Re: PVC Pipe as a tank

PostPosted: Fri Mar 08, 2013 10:05 am
by pappaw
biziedizie wrote:
pappaw wrote:Does anyone know the formula to calculate a size pipe by the length to get the gallons it would hold? :thinking:


Yeah it's pretty simple. : v = hπr2


Boy, that helped alot :rofl:

Re: PVC Pipe as a tank

PostPosted: Fri Mar 08, 2013 10:17 am
by jss06
pappaw wrote:
biziedizie wrote:
pappaw wrote:Does anyone know the formula to calculate a size pipe by the length to get the gallons it would hold? :thinking:


Yeah it's pretty simple. : v = hπr2


Boy, that helped alot :rofl:


Height x radius x radius x 3.14159

Re: PVC Pipe as a tank

PostPosted: Fri Mar 08, 2013 10:31 am
by asianflava
jss06 wrote:
pappaw wrote:
biziedizie wrote:
pappaw wrote:Does anyone know the formula to calculate a size pipe by the length to get the gallons it would hold? :thinking:


Yeah it's pretty simple. : v = hπr2


Boy, that helped alot :rofl:


Height x radius x radius x 3.14159


You guys are missing the last part of the equation, this gives the volume. If you figure it for cubic inches, you still have to divide by 231 to get gallons

Re: PVC Pipe as a tank

PostPosted: Fri Mar 08, 2013 7:23 pm
by 48Rob
Image

Re: PVC Pipe as a tank

PostPosted: Sat Mar 09, 2013 9:07 am
by pappaw
Thanks for the info guys, and that chart is sweet. :thumbsup:

So a 6 inch pipe 6 feet long give you almost 9 gals of water, not to shabby. :twisted:

Re: PVC Pipe as a tank

PostPosted: Sat Mar 09, 2013 5:32 pm
by Bogo
If you go vertical,, just get 5 gallon soda kegs. They can be plumbed in series for greater capacity, cleaned out easily, all connections are on top, you can take them out and carry them to the hydrant for refilling, they can be pressurized to 160PSI, and you can brew in them in the off season... :thumbsup: Just note which type of top fitting your keg has as there are two different types, ball, and ???. Also inlets and outlets use different sized connectors and won't interchange. Direct taps are available to the output, or fittings to quick connect a hose to the outlet. For the inlet, you can get the right fitting, and hook it up to a hose with a schrader valve on the end. Then you can pressurize with any hand pump or an oilless air supply with a chuck. Don't use CO2 unless you want soda water. ;) I've thought of using them in the past for hot water. You can fill with part hot and part cold to get water of the desired temperature and have dish or shower water.

Re: PVC Pipe as a tank

PostPosted: Sat Mar 09, 2013 7:24 pm
by GuitarPhotog
Bogo wrote:If you go vertical,, just get 5 gallon soda kegs. They can be plumbed in series for greater capacity, cleaned out easily, all connections are on top, you can take them out and carry them to the hydrant for refilling, they can be pressurized to 160PSI, and you can brew in them in the off season... :thumbsup: Just note which type of top fitting your keg has as there are two different types, ball, and ???. Also inlets and outlets use different sized connectors and won't interchange. Direct taps are available to the output, or fittings to quick connect a hose to the outlet. For the inlet, you can get the right fitting, and hook it up to a hose with a schrader valve on the end. Then you can pressurize with any hand pump or an oilless air supply with a chuck. Don't use CO2 unless you want soda water. ;) I've thought of using them in the past for hot water. You can fill with part hot and part cold to get water of the desired temperature and have dish or shower water.


Soda kegs are way more expensive than PVC pipe. They're selling for US$50-70 each to home brewers here abouts.

<Chas>
:beer:

Re: PVC Pipe as a tank

PostPosted: Sun Mar 10, 2013 12:49 am
by Bogo
For PVC pipe you'll need a solid core for it to be pressure rated. Also look for a potable water rating. Not all PVC pipes have it. For a 6" 10' long piece it runs around $40. Add in the end caps which will be $9 and up each and the fittings to connect up to the inlet, supply, and vent lines. It also isn't cheap. 4" pipe will be cheaper, but require more lengths of pipe which will increase the fitting costs.

As a price point: a 21 gallon RV water tank can be had for $77, on sale for $58 http://www.pplmotorhomes.com/parts/rv-p ... -tanks.htm That includes 4 tank ports. Others may be cheaper. I only very quickly looked for tanks that were 8" high or less. It's hard to find ones under 8" high.