Pictures of welded fittings, storage

[easternbob]

Getting ready to finally add some storage to my system.
I know some of you will think it's a little small but I've got a line on a 320 gal propane tank that I can fit into my basement. Couldn't fit a 500 gal tank.The tank will be installed horz.
Been reading all the treads about welding and storage wondering a couple things.....

1. I can get some pics of the fittings welded onto the tank? Would be nice to see this.
2. Is the general consensus to install the fittings on the top and then use dip tubes?
3. Is everyone using elbows to direct the flow along the top and bottom? I like the idea of welding 2" bushing and then snaking 1" with elbow down inside.

Thanks. Bob

 

[maple1]

Don't think I have any pics of the fittings per se, but whatever pics I do have are likely in my install thread.

No diptubes here, and don't think I'd say there was a concensus on it. I just went in & out of the bottom & top. Simpler, I think.

Can you get another tank down there & on top of the one you have a line on? Or even maybe a couple or 3 110's on top of it?

 

[stee6043]

I know you don't want to hear this....but I just can't resist.

What is your goal with the 320 gallons? What specifically do you hope to achieve? I really encourage you to put this in writing before you invest in storage. Perhaps you already have!

All things being equal 320 gallons for me, my system, would mean roughly five hours of heat capacity in that tank. So what would I do with those five hours? Am I trying to bridge a gap between the boiler going out after bedtime and before I get up in the morning? Am I trying to create a buffer for when the wife forgets to load the boiler while I'm at work? Do I plan to still run the boiler 24/7 and use this for emergency only?

You may also be in a situation where you'll get more time from the tank than I would. Or perhaps you won't? Do you plan to let your fire go out once a day? If so, is it worth remaking a fire 4 hours after it goes out? Or would it be more efficient to just keep it burning?

I'm sure you already thought of this. I just wanted to chime in. I wish you the best of luck with your storage setup. I have dip tubes in my tanks, no elbows on the bottoms. I did zero welding since I used the existing ports on the propane tanks.

 

[easternbob]

Maple and Stee, thanks for the replies. I'm very luck that the new house I built is small and verrrrrry well insulated (my heat lost calculations was 38,000 btu/hr at 10 below)(SIP construciton, passive solar design). I was estimating that a more average heating day of 15,000 btu/hr. if you do the math with a deta T of 70 I would get nearly 12.5 hours.

Maybe that is a good question..... Many of us know what our max/ worst case btu/hr BUT what is the typical/average btu/hr during winter.

Stee, I haven't picked up the tank yet, are the existing ports on your tanks 'normal' or is your tank unique?

 

[maple1]

Speaking for myself, and with a bit more thought - my tanks had 'normal' ports on them. Normal in that they were pipe threaded holes. So it may be possible, depending on where the holes are in the tank you get, to make do with the holes that are there without any more welding, with the use of a diptube. I forget what size the biggest ones were, but am thinking 1-1/4". Then again, with even a bit more thought - there may have been one hole that wasn't 'normal' - that being the one where the guage was. I think I had a plug welded into that one.

My memory ain't what it used to be...

 

[stee6043]

Maple and Stee, thanks for the replies. I'm very luck that the new house I built is small and verrrrrry well insulated (my heat lost calculations was 38,000 btu/hr at 10 below)(SIP construciton, passive solar design). I was estimating that a more average heating day of 15,000 btu/hr. if you do the math with a deta T of 70 I would get nearly 12.5 hours.

Maybe that is a good question..... Many of us know what our max/ worst case btu/hr BUT what is the typical/average btu/hr during winter.

Stee, I haven't picked up the tank yet, are the existing ports on your tanks 'normal' or is your tank unique?

Sounds like you've given it some thought. Excellent. What type of emitters do you use? My average heat load is in the 19k ballpark (my max is closer to 50k). But realistically I'm only working with 40/50 degrees of useable heat. 70 would never happen for me.

My propane tanks came with 4 or 5 threaded ports. I used two each plus one for a vent/fill on each.

 

[jebatty]

A 320 gallon tank with your low heat loads can work very well as you describe. Diptubes also can work satisfactorily. My best of all worlds would have 2" female fittings cut and welded into the ends of the tank, close to the top and close to the bottom, on both ends. Charge the tank with hot water in at the top of one end and return water out from the bottom of the opposite side. Draw from the tank with hot out at the top of the other end, and return water back into the bottom of the opposite side.

That said, with my system I had 2" female fittings cut and welded into only one end of the 1000 gal tank. The top fitting has an 18" +/- smaller diameter pipe welded into the end of a 2" male threaded pipe which then is screwed into the 2" fitting. The extension then shoots hot water from the boiler across the top of the horizontal tank in an effort to maximize stratification -- works well. The bottom fitting just draws return water to the boiler directly from the bottom fitting.

My low temperature in-floor pex then uses the tank fittings in about the middle of the tank. Hot water is drawn directly from a top fitting and with a diptube return water uses another fitting. This results in substantial tank mixing. The very hot water to the pex is mixed down to 100F, so return water from the mixing valve is quite hot and is returned to the bottom of the tank. Mixing is not an issue because I only need 100F water anyway for the in-floor. Normal operation is to charge the tank to 180-190F and draw it done to about 110-120F before recharging.

My system does not provide DHW, and if you intend to do that with your tank, mixing can be an issue due to the reduced stratification and lower temperature water in a coil or heat exchanger to heat DHW.

 

[easternbob]

Wow that is interesting you max load is 50 but your average is only 38% of that. I guessing this is the average over your entire heating season?
I have radiant for the first floor and euro style radiators for second.
Lets hope my tank has some thread ports that would make life easier!

 

[stee6043]

Wow that is interesting you max load is 50 but your average is only 38% of that. I guessing this is the average over your entire heating season?
I have radiant for the first floor and euro style radiators for second.
Lets hope my tank has some thread ports that would make life easier!

I'm sure you get decent swings in winter temps up on NY? My "average" winter day is probably something like mid/low 20 degrees, a touch of sun, not much wind. An extreme day (we'll get a handful each year) is below zero much of the day, wind chills of -20 +/- and zero sun.

I have to be rather judicious in how I pick my wood/splits on the days I know I'll approach peak loading. I need every ounce of heat from the wood to go into those tanks to avoiding having to get up in the middle of the night to add "one last load" to get me through the day at work the next day.

But again, I'm much closer the 40 degree delta T figure on my system for useable heat. Timing is everything if I'm to keep my tanks in the sweet spot on those really cold days.

 

[Coal Reaper]

https://www.hearth.com/talk/threads/sending-500-gallon-tanks-verticle.107273/

advise use weldolets for fittings. i welded nipples right to the tank and they were a PITA to get sound welds. i dipped a bit into bottom of tanks and theres a pic of top diffusers on second page of above link.

 

[Tennman]

Eastern, I didn't use weldolets because I didn't want any threaded joints under the foam. Instead I bought Sch 40 1 1/2" x 12" or 14" nipples, cut them in half and welded those to the propane tank. That left ~2" of the male NPT extended beyond the surface of the spray foam insulation. We of course leak checked all welds using 1 1/2" caps, soapy water, and ~8-10 psi before foaming. Make sure you leak check the welds. We found a few pin holes we had to weld.

Also I didn't do a dip tube based on successful systems like pictured. Our 500 gal tanks are vertical with 5 ports. The 4 as usual, but one exactly in the middle to help normalize temp between the tanks. There are two angles welded slightly above the tank's CG so we could handle and rotate them with the fork lift's blades. They've now been cut off flush. These things look like something from Sesame Street. Sorry the image is sideways, not the tanks.

 

[salecker]

When i did mine i tested to 80 psi.
My supplier of plumbing parts ,boiler and expertise recommended the high pressure test of all plumbing ,tanks,and cast iron rads.His reasoning is "get rid of the wimps before they are part of a heating system you rely on at -40C"and "God hates a coward"
Anyhow i did find a pinhole leak at one of the welds on my tanks and had to get the welder back to redo the one weld.It never started to leak till i got over 40PSI in the tanks.
When i tested my complete system i only had a couple of leaks,which were all on recycled copper fittings.I had 100's of soldered,and 100's of threaded fittings.90% of my copper was recycled pipe and fittings.I was taught by him how to use Hemp for the threaded fittings,so far i haven't had a threaded fitting where i used hemp leak,and i use it on all threaded fittings now.
Thomas

 

[jebatty]

Amusing story on pressure testing welds which I have posted before. The welds done by my welder were visual works of art, two passes, very smooth. I then asked him if I should pressure test the welds, and he said "no." I then asked him why, and he said he welded 3000+ psi piping at the local nuclear plant. Needless to say, I did not pressure test the welds.

 

[easternbob]

Finally got my 320 gal. tank yesterday. I think with the existing fittings I should be set since I will be using the tank in a horiz. position. I see one of the smaller fittings (just slightly less than 1" ID) is a dip tube that runs down to with in an inch or two of the bottom. Has anyone used this for their cold water return? Just wondering if it's too close to the bottom, also a little concerned about it's diameter.
The only thing I'll need to work on is to patch a 5/32" hole they drilled in one side of the tank. Looked pretty clean inside and didn't stink too bad.