Suggested tappings on storage

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toothy

Member
May 7, 2009
14
Seward Alaska
Hello All

I am starting on my 2 vertical 500 gallon propane tanks for storage.

I understand I need water in and out the top and bottom, I am going with 2" to cut velocity to reduce stirring. I'm also putting a domestic coil in a 4" tapping.

What other tappings are needed, and where, what about any extras you now wish you had put in? How about aquastat well and their position?

I'm heating it with a Tarm 2000 @ just over 100K btu output.

Thanks
Wade
 
I understand I need water in and out the top and bottom, I am going with 2" to cut velocity to reduce stirring. I'm also putting a domestic coil in a 4" tapping.

What other tappings are needed, and where, what about any extras you now wish you had put in? How about aquastat well and their position?

To use the entire tank, ideal would be a single port on the very top and bottom of each tank, with reverse return manifolds.

If ports enter vertically you could consider some kind of diffuser, but with 100k btu per hour flow split between two tanks with 2" ports it would likely not be worth it. Supply temperature aquastat can go in a tee into the upper manifold above the tank. Existing side ports can be used for tank temperature monitoring wells, but sensors taped to side of tank would work A-OK.

You may want to plumb in a port halfway up one of the tanks for injecting solar heated water if solar may become part of your plans.

Tankless coil in top of storage is a great idea if it works for your situation.

--ewd
 
Thanks Ewd

I didn't know I could put the aquastat in the pipe, thanks.

I will have a tapping for future solar and some also for my 5Kw of spare solar electric diversion in the summer. I'm running the dhw into an instantaneous propane unit so hopefully it won't even fire.

Up here we have to run evacuated tubes to get much production, it's on the list but not at the top, the boss has other priorities.

I cut the end out of the propane tank inverted it and welded it back in, it makes a great foot, with some loss of volume.

Thanks
Wade
 
I didn't know I could put the aquastat in the pipe, thanks.
Assuming it's situatated where hot water will rise to it
I cut the end out of the propane tank inverted it and welded it back in, it makes a great foot, with some loss of volume.

Don't know if it would be worth it, but since you have the capability you may want to study some of the European storage tank system enhancements.

Specifically, they like to use internal ducting to allow heated and cooled flows to travel vertically to find their proper elevation with minimal mixing.

In your case a funnel attached to a six inch (PVC) pipe underneath the DHW coil would catch the cooled water falling from the coil and direct it to a lower elevation. Ports in the side of the vertical pipe allow the cooled water to exit at the correct thermal gradient. A final enhancement would be to run short pieces of pipe at a downward angle into the vertical pipe to prevent entrainment mixing through the ports into the downward flow.

Likewise they use vertical risers to take solar heated water up to the proper level.

Myself I just let the flows fall or rise as they please and if they mix some it doesn't seem like such a big deal, I start a fire from time to time in the summer to keep the top of the tank hot and the heat added by solar is not lost.

And BTW if you're ever in this neck of the lower forty-eight I suppose a must-see would be your town's namesake museum:

http://www.sewardhouse.org/Explore/AbouttheFamily/tabid/99/Default.aspx

As Secretary of State the guy got around a lot and the family left priceless collections intact for the museum.

--ewd
 
Thanks for the link the wifes brother is in Rochester, we may get back that way someday.

The stratification improvements sound like good ideas but I'm just painting in broad strokes and trying to get it all working. A btu is a btu as long as it's in the tank it will find it's proper place. Those measures should help to ring the last ounce of efficiency out of a system.

We have a Dudley up here of the Michigan or Minnesota variety, he used to be my neighbor now he's a couple miles away.

Thanks
Wade
 
I just had mine done. The welder closed off one that I had wanted. Now that I look at mine.. Here's what I have, and what I wish.

I've got 2 down low. just above the dome.

I've got 2 up high, just below the dome. All of those are 2"

I've got 1 at Top Dead Center of dome. 1 at bottom dead center of dome. Those are 1.5"

I've got 1 at height of top 2" that is a 3/4"

I wish I had one more 3/4 at the level of the other one. and one more 3/4 at the level of the bottom 2" Then I could have one 3/4 for the boiler computer, and one top and bottom temp for a display or logger or such. I'll have to get by with putting wells in my drain line, and in my vent line on top for that stuff.

JP
 
My quick thought is that 7 tappings should be lots - will you be needing all of them? You could always reduce down a bigger one(s) to 3/4.
 
My quick thought is that 7 tappings should be lots - will you be needing all of them? You could always reduce down a bigger one(s) to 3/4.
Two each up high. One Wood boiler input. Other feed to emitters. Two each down low. One return to wood boiler, one return from emitters.

Top and bottom two are rarely used. One on top for venting air during fill, one on bottom for sediment drain.

JP
 
Cool... My first post on the hoity toity new spiffed up site.

Perfect timing on this for me. I will be using two 500 gal vertical tanks also. I've seen tee'd lines entering and exiting below and above the dome weld seam. Obviously not at the absolute top. So is everyone here saying having the most separation between entrance and exit gives the best thermal gradient and best for mixing? My fab guys don't care where or how to handle, so I get to put it at the BEST place. Good tips about adding some 3/4" for temp wells. If the exits are right on the bottom I can tee off separate drains and add ports for air vents at the top. I'm kinda hoping ya'll say very top and very bottom jointed to a tee manifold is the best from a Thermodynamics and stirring standpoint. Looking for 500 gal tanks right now. Jazzed about storage for next year, but more enjoying the Spring weather with windows all open!
 
One further thought - some pipe storage only in from boiler supply to top of storage and out to boiler return from bottom of storage. The loads are T'd into the pipes outside the tanks - no need for water to travel thru the tanks to get to loads if the boiler is heating & there is a demand for heat. That would free up 2 of your holes per tank.
 
here is how I did mine. I'm not saying it's the best way to do it, but it does work good for me. I only used one y strainer on the return to catch any debries coming out of the tanks instead of the two at top as shown. with the supplys in the pipe you get hot water as soon as the boiler is hot. If
your supplys are in the tank you have to heat the tank down to your supply to get hot water.
If the supply is near the top of the tank you shouldn't have to wait to long.
 

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Possible silly question:

For fittings that are to be welded onto a propane tank, then plumbed to copper, what material should they be made of? I've seen stuff called steel, black steel, & black iron. I know galvanized needs to be avoided, but aside from that ... ?
 
Possible silly question:

For fittings that are to be welded onto a propane tank, then plumbed to copper, what material should they be made of? I've seen stuff called steel, black steel, & black iron. I know galvanized needs to be avoided, but aside from that ... ?
I used a welder.. but I think I'd use something of good quality. This is what I was looking at. I could read you the specs off mine in a few days when I get home.

http://www.mcmaster.com/#weld-on-tank-fittings/=h1rr5l

JP
 
Possible silly question:

For fittings that are to be welded onto a propane tank, then plumbed to copper, what material should they be made of? I've seen stuff called steel, black steel, & black iron. I know galvanized needs to be avoided, but aside from that ... ?
Steel. Don't use cast fittings they dont work and can look a lot like steel.
 
Am I right that typical 'black iron' pipe/fittings is really steel and is OK?

The only things to really avoid are galvanized, and cast iron fittings?

I think I will use some long nipples cut in two - a weldolet would make a great place to screw a pipe into no doubt, but would likely end up pointed in the wrong direction if tapped into the rounded end of a tank. Or maybe not - something else to ponder along with the 389 other things bouncing around in my head on this...
 
Maple..

I think the warning would be just to take care WHERE you get them. Cheap Chinese fittings could make more work than the small savings is worth. Find a good plumbing supply house, or take a look at the link I provided.

JP
 
Yes, actually I had studied the weldolets before - they look good. I think my welder guy I have lined up (he's a real pro) has pipe & fittings on hand, but I haven't confirmed that yet - I should do that first I guess.

Hoping my first big step of obtaining & dragging home some tanks will be coming soon. Then it'll be no looking back...
 
Read, Read, Read.. ask questions, and read some more. I'm just 6 months ahead of you is all. I researched, and in the end, the pro welder just said.. I got it. He used the fittings he wanted to. They look like they were made for it.

Use good parts, use good people. I'd rather wait and do something right the first time, than pay twice trying to save a buck.

JP
 
Read, Read, Read.. ask questions, and read some more.

JP

That's all I've been doing since I joined this place (and what a great place it is). I go to sleep thinking about gassifiers, and wake up thinking about propane tanks. I think I dream about pipes in between. It really is a wonder I haven't gotten myself fired yet...
 
Oh I'm on thin ice with the wife too. It's down to the wire. The master bathroom better get done before she has to see that gasifier go! I think I'll have to sneak the first fire! Granite was done on the bath monday. But my plumbers are faster than my tile guy!

I'll sneak the inaugural fire.. then It'll give the bathroom guy an extra week, as I go away for twice a year training for a week Sunday.

JP
 
Thanks Ewd

I didn't know I could put the aquastat in the pipe, thanks.

I will have a tapping for future solar and some also for my 5Kw of spare solar electric diversion in the summer. I'm running the dhw into an instantaneous propane unit so hopefully it won't even fire.

Up here we have to run evacuated tubes to get much production, it's on the list but not at the top, the boss has other priorities.

I cut the end out of the propane tank inverted it and welded it back in, it makes a great foot, with some loss of volume.

Thanks
Wade
 
Nice project. I like the base idea for the tanks.

Run some numbers when you decide to go solar. A T-sol simulation for Seward shows 20 evac tubes (31 square feet) 50 gallon tank 120F operating temperature with a solar fraction of 32%.

A 4X8 flat plate collector, same tank has a SF of 31.7.

The CCHRC.org Cold Climate Housing Research Center in Fairbanks has some good comparison data between the different types of collectors. They have flat plate collectors mounted vertically on their building. The Weller School project over there has a row of plate collectors to warm the GEO field also.

Keep the snow off them with a steep mounting angle, evac tubes do not shed well. I read Anchorage had record snowfall this year, how about Seward?

I spent two weeks in your area last summer and had a great time hiking and kayaking. I can't wait to return.

hr
 
Thanks for the projections on the collectors, I know our solar resource is less than spectacular.

I'm buying my masonry heater/oven core kit from a guy who works at CCHRC.

We get quite a bit more snow than Anchorage, Seward in town has had somewhere around 250" but we get more than town. A guy at Bear lake 3+/- crow flight miles from here has measured well over 400" where Anchorage has broken their record at around 134". The subdivision roads are down to one lane, it's kind of hard to figure out where you are at because all the landmarks including houses have disapeared, but their slowly coming back into view.

Glad you had fun in the hood. My house is the white blob timber frame with the fancy Lowes tyvek siding so far, on the hill at the head of the bay.

Wade
 
Am I right that typical 'black iron' pipe/fittings is really steel and is OK?

The only things to really avoid are galvanized, and cast iron fittings?

I think I will use some long nipples cut in two - a weldolet would make a great place to screw a pipe into no doubt, but would likely end up pointed in the wrong direction if tapped into the rounded end of a tank. Or maybe not - something else to ponder along with the 389 other things bouncing around in my head on this...

The weldolots are thicker steel. That being said, I did as you mentioned and cut a nipple in half and welded a half at the top of each tank. Works great so far. I figured if it ever did leak I wouldn't loose much water being at the very top of the tank. It is hard to find the center and get them pefectly verticle. Mine are not perfect. but I only used a 2 inch nipple on each tank so not much to judge by.
 
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