Help with storage plumbing 2.0

[maple1]

Not sure what 'ideal' would be. But I used 6x6 timbers, and chain sawed out a profile in them to fit the bottoms of my tanks (pics in first few posts of my install thread). After things were in place, I could jamb 2 thicknesses of 1.5" foamboard underneath the tanks. That's not as much insulation thickness as I have all around the other sides, likely would be better if I had more. Kind of a 'do what you can' kind of thing likely, and you don't want to short yourself on headroom if it's real tight.

 

[warno]

So basically what ever I can cram under them is good? Probably a dumb question but, Does the foam board hold moisture at all?

 

[warno]

So I'm dragging this thread back up again since I've started working on this project again.

I'm back with a question of plumbing my expansion tank.

I've realized I simply cannot put my expansion tank up in the rafters of my garage, it's simply to much weight for their design. So my only option is on the floor next to my storage tanks.

Is there any way to plumb my plain steel expansion on the same level as my storage and not get air back into my system?

I also changed my orientation on my storage tanks. I'm going with the 3) 250 gallon tanks stacked horizontal one on top the other 3 high.

 

[warno]

I've been trying to rack my brain about keeping this air bubble in my ground level expansion tank versus it getting pulled back until the system. Going out on a limb here but could I purge the "air" from the air bubble and replace it with helium? Or argon? Would this work or be a waste of time?

 

[leon]

if you have a 30 gallon expansion tank in the rafters you will have 20 gallons of water and the weight of the tank and the airtrol valve resting on 6 sets of pipe straps secured between the rafters of the garage you will not have issues with the total weight.

Short of simply buying a bladder expansion tank sized for you system and total storage volume that will sit on the ground that is your only other option.

 

[warno]

All the expansion tank calculators I've used say I need close to 100 gallons of expansion for about 800 gallons total system water.

So that's close to 70 gallons of water hanging from my 2x4 with 24"OC rafters. It will be too much weight. Maybe not at first but it will start pulling to roof down.

 

[maple1]

Yes, you will need more than 30 gallons.

Can you build a stand for it to get it as high as possible? The space under it could then be used for storage.

Another possibility might be to use 2 expansion tanks. A smaller (cheaper) bladder tank tied in around the inlet of your system circ where an expansion tank would normally be tied in, then your bigger one could tie in somewhere away from your circ. Like the far end of your storage tanks, or the like.

(Not seeing any benefit to replacing the air with another gas).

 

[leon]

Is there any reason you cannot sister six or twelve garage
width 2 by 4's together to create more strength in the rafters
and then hang 5 20-gallon steel expansion tanks along with the 5 airtrol valves?

I have never heard of 2 by 4's being used for rafter cross ties myself
the minumum size we have here is 26 by 6 or 2 by 8 for the cross tie timbers
depending on the rafter spacing.

The alternative that would work is to hang the steel expansion tanks and airtrol valves
along one wall of the garage using the side walls lumber to support a continuous shelf
made with two 2 by 8's that has a 2 inch width separation to allow the fitting of pipe to
the bottom of each tank then each tank could be cross connected with Pex to tie in each
tank to the common riser pipe with the 2 inch opening in the center of the two 2 by 8's.

You can add more strength by screwing and gluing 2 by 4's to the 2 by 8's from each rafter
creating a longer set of reinforced timbers with lumber connection plates.

As long as you hang the riser pipe and cross connection pipe properly to create the rise needed
to get the air out you will have no problems.

 

[warno]

To maple,

The "tank" I'm using was actually going to be 4) 25 gallon tanks plumbed together. So I have options of using smaller tanks. My storage tank stack will measure 93" of my 96" ceiling height in my garage. That's why I hoped I could put the expansion in the rafters until I figured out they wouldn't hold.

Maybe another dumb question here but why does the plain steel tank need to have so much water in it? Why can't it just have the air cushion alone?

To leon,

That sounds about like rebuilding my whole garage ceiling. In the cost of lumber for my 20 feet wide garage I'd probably have enough money to go with a bladder tank. I'm only going "plain steel tank" here to save the money because I already have the plain steel tanks that equal 100 gallons. So if I'm spending a ton of money in lumber I'll buy a bladder tank and plop it next to my storage and call it good.

 

[maple1]

Maybe another dumb question here but why does the plain steel tank need to have so much water in it? Why can't it just have the air cushion alone?

Theoretically, it is empty - when your system is fully cold. Or almost empty. When it is fully hot, it is partly full. It should never be full - if it is, it got water logged, and your system will have too much pressure as a result.

EDIT: Another possibility on the joists & where to put them, might be to use a jackpost or two for support.

 

[warno]

I took a couple pics of the expansion tanks and another potential area I'm wondering about. Also the area where I'm putting my storage tanks, And 1 of the 3 I have for storage.



So here's 2 of 4 for the expansion tanks. They measure 14" by 48" give or take alittle. I plan to plumb them end to end with 2) 1" pipes 1 high and 1 low to allow water and air to flow in and out as needed



I'm wondering about putting the storage above my garage door header and putting gussets down the length of the header to support the load. Would this 2 X 12 header with gussets down the face hold the load?

Here's the header





Here's one of my 250 gallon storage tanks



And here's where they are going. Where my ladder and jack are at. It's going to be a tight fit between the wall and rail for the garage door. To be honest I don't know for sure it's going to fit but I've measured it for the radius of the tank best I can and I should have about 1" clearance.

 

[maple1]

Maybe a nice mod will come along & embed those.

 

[warno]

I wondered why the pics didn't show up. Can you not open the links?

 

[leon]

About your steel expansion tanks, you cannot connect them/PLUMB THEM end to end and expect them to work.
They wont. The air has to stay trapped in the upper third of each tank at all times.

They have to be cross connected with one Airtrol valve in the "HORIZONTAL" BASE TAPPING of
each tank with a Tee connection from the common header riser pipe to each of the three tanks.
If you do not have one or two one inch or one and one quarter inch tapping's in the side of the tanks
to install the cross connection piping for the riser pipe you will never get it to work because the water level cannot be regulated and drained as needed.

 

[warno]

I planned on making basically a really long 14" diameter tank. Which is what I meant by connecting them end to end with pipes.

Picture the tank on its side. I'm going to hole saw holes in the face of the end top and bottom and weld in a 1" pipe. The water will flow in from one tank to the next and be balanced by the air flow moving from tank to tank via the top pipe. The inlet fitting will be in the first tank in the chain. I see no reason why this won't work. It will basically be a 17 feet long 14 inch diameter tank when I'm done. Why won't that work?

Like this, the red lines are my pipes from tank to tank and the blue area is my inlet fitting to the "tank"

 

[leon]

It still will not work because your design allows the air escape into the system
rather than contain it and you will have air bubbles galore to deal with.

you also have no way to regulate and control the amount of water to air ratio in your "tanks"

The six laws of gasses are not and will not be your friend here in what you have planned versus
what I have labored to describe to you in great detail for what you need in my opinion.

 

[warno]

Where is my air escaping into my system if there's an airtrol fitting in the tank inlet port?

I thought the airtrol fitting controlled the water level after initial fill up?

Help me understand why this as a expansion tank will not work with an airtrol fitting in the "inlet" port? The tanks are horizontal in a line tied together. Why does it matter if my tank is 50 inches long or 50 miles long? If the water can move freely in and out from tank to tank, which it would, why won't it work as a normal plain steel tank?

 

[leon]

Where is my air escaping into my system if there's an airtrol fitting in the tank inlet port?

I thought the airtrol fitting controlled the water level after initial fill up?

Help me understand why this as a expansion tank will not work with an airtrol fitting in the "inlet" port? The tanks are horizontal in a line tied together. Why does it matter if my tank is 50 inches long or 50 miles long? If the water can move freely in and out from tank to tank, which it would, why won't it work as a normal plain steel tank?

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If as designed in your drawing your water moves in the tanks and the air moves with it and will
cause cavitation and premature pump failure.

You have to hold the air charge captive by having a set volume of water to hold it in place and to let the hot water and microbubbles travel upward into the cooler water and the air gap and then the cooler watwer falls back in to the system or storage tanks and the way have the drawing now you are not holding the air charge in both tanks captive with your design that is why.

Unless you plumb the tanks exactly like the B+G diagram for multiple tanks it will not work.

If you plumb them in series the air charge MUST be held in place using a common header pipe and the two airtrol valves
being fed water from a common header pipe from the top of the storage tanks if you OWB is not pressurized.

With what you have now; the purchase of a single or two smaller hot water rated bladder tanks
mounted on the floor will be less work and simply be plumbed in with a Bronze Tee or Tee's.

 

[warno]

You do realize that water WILL flow through the bottom pipe to the next tank on a level field from tank to tank to tank to tank Because the pipe in the top of the tanks will let the air cushion be moved from tank to tank to tank to tank. If I had a vent in the top of any one of the tanks and an inlet in the bottom of any one of the tanks and started filling with water, it would fill each tank evenly across the length of all 4 tanks. How are you thinking this could not possibly work? All of these tanks are level with each other, it is literally a REALLY long single tank.

I would have the water level at 2/3 the total volume. so the air would be trapped in the top of ALL the tanks. If this whole apparatus is above my storage tanks with a pipe going up to the airtrol fitting how is it not going to act as one tank?

 

[maple1]

I do not see why that would not work. As long as the bottom tank connections (and the one to the boiler) are all at the very bottoms of the tanks for water movement, and the top connections are at the very top for air movement. I would also T in a bleed valve somewhere in that top piping, maybe also a pressure valve too. Along with an isolation valve to isolate these tanks from the rest of the system, and a drain valve in the bottom piping so you could drain the tanks if needed.

Expansion is pretty simple - you're just creating a sealed empty space for water to expand into as it is heated. The catch is that is needs to be big enough that it won't raise the pressure too much as the air gets squished when it does warm. 100 gallons should do it.

I also wouldn't bother with the airtrol stuff for expansion tied to storage tanks. Just get them as high as you can, and getting them away from the tanks (like another side of the room) will also reduce air worries. Make sure the piping from expansion to storage tie-in is downhill all the way, or has no high spots for an airlock to happen.

What's it look like along the top edge of your walls, around the rest of the room? Can you do that same thing you want to do above the garage doors, somewhere else? You should be able to tie/support them to the walls & the ceiling joists both. With the weight at the ends of the joists right above where they sit on the wall, it won't strain them much. As opposed to hanging them from the joists in the middle of the room. But maybe above the door is the best out of the way spot, as long as they will fit & there's room for the piping.

 

[warno]

I planned on my "inlet" in the expansion to have a drain and a pipe coming from the storage and also, I didn't draw it but, adding a vent valve for filling and draining proposes.

The rest of the garage ceiling to wall area is open but I wanted to keep all my boiler stuff packed in this one corner since my garage is only 20 X 25.

When I said "above my garage door header" I meant taking out the ceiling dry wall panels and setting the tanks as close to the wall in that area. Then adding in my gussets down to the header of the door. It's all wide open up there but the tanks would be off to the side, face, of the header, which is the reason for the gussets tieing to the header board.

Thanks for the second opinion, I'll keep looking at other options as well. I'm still in the midst of stacking my storage tanks so I have some time before the expansion really needs pinned down.

 

[leon]

You do realize that water WILL flow through the bottom pipe to the next tank on a level field from tank to tank to tank to tank Because the pipe in the top of the tanks will let the air cushion be moved from tank to tank to tank to tank. If I had a vent in the top of any one of the tanks and an inlet in the bottom of any one of the tanks and started filling with water, it would fill each tank evenly across the length of all 4 tanks. How are you thinking this could not possibly work? All of these tanks are level with each other, it is literally a REALLY long single tank.

I would have the water level at 2/3 the total volume. so the air would be trapped in the top of ALL the tanks. If this whole apparatus is above my storage tanks with a pipe going up to the airtrol fitting how is it not going to act as one tank?

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Again, the air is trapped with the airtrol valve and cannot be released unless you open the drain valve. With your current design it will gradually be replaced by water as it is not held in place by the airtrol valve.

 

[warno]

I did not draw the airtrol fitting in but it will be threaded in the "inlet" of the tank, like I said, so I ask again how is my air getting back out?

 

[warno]

I would also like to add there will be no automatic fill in this system. Only way it can get replacement water is by me hooking my hose up to it and adding water.

 

[leon]

As long as you have each airtol valve in the base of each tank fed by a "common" single header pipe fed and drained at the bottom and do not use the cross connected pipe at the top it will be fine.

The upper pipe you have drawn in is not required or needed as it will cause you nothing but problems.
The addition of the upper pipe will affect the air to water ratio and will create the wrong volume of air to water until the tank becomes water logged. That is why you need an airtrol valve in each tank with no upper tank cross connections as the air has to be held in place.

The B+G drawings show multiple tanks connected at the bottom with an airtrol valve in the base in each tank.
Each tank will be drained of water by each airtrol valve and then have and maintain the proper air to water level ratio with no issues.