My 2 x 500 gal tank design..... do your worst

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churchillrow

Member
May 21, 2008
56
Northern Nova Scotia
Here is My first shot at a design for 2 500 gal tanks based on comments from the previous thread. Any thoughts/critiques/sarcastic comments would be welcome. Biomass here tomorrow, tanks to welder on monday.... yahoo!!!!


Thanks,
Augie
 

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Pretty much how I'd do it, but I'm not a welder so I don't know the implications. Looks like you'll end up with a monolithic structure - access to weld the short pipes between the tanks could be a challenge, and cutting the oval holes for the diffusers also looks fun. Let us know how it goes.
 
Looks cool but are you at all concerned with eventually breaking the welds on the "diffusers"? That's a lotta pipe hanging off the end. I suppose if your welder says you're good to go there won't be much to worry about.
 
I am just picking up my 500 gal tank today. I need to have a port welded in the bottom and probably a bigger port in the top. I have read on previous threads that others have installed the diffuser using copper fittings, so that the pipe enters the top of the tank, turns 90* and runs along the top. How is this done?

If I simply have a port in the top and one in the bottom at the opposite end of the tank, will this cause too much mixing during tank loading?

Just wondering before I get the tank to the welder.
 
My intention is not to end up with a monolith.... I'm thinking I'd be better off offsetting the connectors between the tanks, then i can use elbows to get them together after the welding without worrying about perfect alignment. Oval holes.... I'll have to see what the welder says about getting those in. I suppose I can do the 90 deg. diffuser thing to..

Augie
 
The oval holes should not be an issue at all, nor should the the diffuser welds its not like it's gonna be subject to a lot of bouncing like on a truck or something.

Do you really think that three connections between tanks are needed? I suppose the more there are the less mixing you will have but it seems like a pain
to plumb. I would think a single pipe with diffusers on each end would do and may result in less cussing from the plumber(myself in my case).

I Would consider a bit larger pipe for the "manport". My thought is a "spool pipe" like is use for a water service in a commercial building. basically a pipe with
a flange on it that mates with a flat cap via gasket and bolts. Would allow for inserting heat exchangers for DHW or solar w/glycol or whatever. I would use
6 or 8 inch but you may not have a need for it.
 
Thanks for the ideas kabbot. Now that I think of it, it is true that one 4" connector has a larger area than three 2" so perhaps that is the route to take. I hadn't considered diffusers on the tank connectors but I suppose they are as necessary there as anywhere. Spool pipe eh? Nice to know the vocab when looking for this stuff... I will check it out.

Biomass 40 here today!!! wrapped in vapor barrier on the hay wagon...waiting for the tanks to go down together.

Augie
 
Here is a pic of a somewhat larger flanged pipe w/cap. prolly a little tooooooo big but you get the idea. :coolgrin:

A 6 inch version has like 8 bolts on the flange.
 

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Now that is a MANPORT. Any thoughts on how to mate the curved top of the tanks with the flat flange of MANPORT.
 
I have one 500 gallon tank now, I've thought about stacking another. I figured welding in two 6" nipples about 12" long between them. That would twin them in and stack them securely. If the tanks then become top heavy, I'd have to anchor the top tank to the wall with a steel brace.
 
churchillrow said:
Now that is a MANPORT. Any thoughts on how to mate the curved top of the tanks with the flat flange of MANPORT.

Well the bigger it is the harder to fit but with say 6 inch if were doing a single hole i would just trace the contour of the tank on the pipe and cut to fit, more than one
port and it would pay to make a template. You can buy flanges to weld on the pipe and the caps come tapped in various pipe thread sizes or solid. So you just weld
the flange to the whatever length pipe you want and then weld the pipe to the tank.The picture is 20 inch DIP(ductile iron) but the idea is the same just with steel
pipe.

The pieces are not cheap but if you know anyone involed in the utilitie trade you may be able to scrounge something, I come across the caps fairly often. They are
plenty heavy for this purpose. The pipe in the pic was tested @200 PSI.

The pics is a sewer force main at a pumping station(A shi**y job) It would take me 2 days to heat up the valve at the bottom of the pic. That is me
at the bottom right with my head out of the frame, camera shy... :red:
 
Looks pretty good to me...

I might be tempted to run the diffuser pipes the length of the tanks so that I could use the tanks as a giant "hydraulic separator" with the boiler hooking up on one end and the loads on the other.... Though you might need to offset the manway to dodge the diffuser pipe...

I would talk to the welder about the best way to do the unions between the tanks - I don't think you really need diffusers on them, but I would try to keep the amount of intrusion into the tank on each side to a minimum... Also the more area you have for exchange between the tanks the better, at least in theory...

How are you planning to stack the tanks and support them?

I am NOT a welder, so I may be way off on this concept, but my thought would be that the best way to do it would be to assemble whatever racking you are planning to use, and put the tanks on just like you are planning to install them, and then put the junctions in using straight unions so that everything is lined up like it will be in the final setup... Then take it apart, move to the final location and reassemble. Hopefully if there are any problems with this idea, our welder / plumber members can say so, and suggest alternative approaches that would work better...

Remember that you will be dealing with a LOT of weight - figure about 2 tons of water per tank, plus the weight of the tanks themselves... This is NOT something that you would want to rely on the fittings alone to support. My personal choice would be to look at the warehouse pallet rack setup I've seen several mention. That would provide good support and repeatable assembly if doing like I suggested above...

Gooserider
 
Looks pretty good to me…
I might be tempted to run the diffuser pipes the length of the tanks so that I could use the tanks as a giant “hydraulic separator” with the boiler hooking up on one end and the loads on the other….  Though you might need to offset the manway to dodge the diffuser pipe…

would you do this for both pipes or just in the top tank? I can see how it would simplify plumbing to have the loads down stream of the tanks but what is to be gained from having the return from the loads travel through the bottom of the tank?

I am going to look at some used pallet racking next week.... A union would be nice but I'm wondering if I'll find one for 4" pipe, i'll
have to look around
 
churchillrow said:
Looks pretty good to me…
I might be tempted to run the diffuser pipes the length of the tanks so that I could use the tanks as a giant “hydraulic separator” with the boiler hooking up on one end and the loads on the other….  Though you might need to offset the manway to dodge the diffuser pipe…

would you do this for both pipes or just in the top tank? I can see how it would simplify plumbing to have the loads down stream of the tanks but what is to be gained from having the return from the loads travel through the bottom of the tank?
The return has to make it back to the boiler from both the house and the tanks, by having both the return and the supply feed through the tanks, you get an automatic flow balancing, regardless of whether the tank is supplying heat or charging. It's a very elegant approach to use the tanks as a hydraulic separator, and it allows the boiler and the house load pumps to run at different rates without having any impact on each others circulation. You wouldn't HAVE to do the bottom, but it would work better if you did.

Look up some of the various tech articles on Hydraulic Separation...

I am going to look at some used pallet racking next week.... A union would be nice but I'm wondering if I'll find one for 4" pipe, i'll
have to look around

You can get all sorts of plumbing fittings if you go to the right places, which means a plumbing or industrial supply place, NOT your local big-box... It is possible that you might not find the same style "big nut" style unions that you get with little pipes on a larger size, they might use a flanged coupling instead, but the concept is the same... Another option, which might be pricey (suspect it would be, but I haven't looked) is to look into flexible couplings - I've often seen them in setups where vibration can be an issue, or where it can be a challenge to get all the parts lined up precisely. Essentially it is 2 flanged fittings connected by a short length of very heavy duty hose, with just enough give to let one line up the parts on each end...

This is the kind of question that I would largely leave to your welder - Tell him what it is you want as an end result, and leave the details of how to get there to him...

Gooserider
 
I second Goose's suggestion to consult with your welder on design. I made a number of suggestions that were impractical in my welder's opinion. I hit upon my rather over elaborate scheme (current thread going on about that) for connecting two 500s after talking the problem over with him. What I came up with solved a number of issues at the cost some long but simple weld beads. He'll know what he can do and probably knows some solutions that would never occur to someone who isn't a welder (like me, for instance).
 
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