weld-in fittings

[kjahnz]

just a quick question, does any one have a source for weld in fittings? my pressurize storage project needs some help. a link to a supplier that has steel weld in fittings would be appreciated. thanks.

 

[ewdudley]

"Forged steel half coupling" is a good way to go. Just contour with grinder a little to fit your tank. Weld-o-lets are also popular but are a lot more expensive and don't have any real advantage for what you're doing. Should be available from most any plumbing supply, e.g., F W Webb or Grainger.

If you're short on clearance you can cut off the end of a nipple, grind to fit, and weld it on directly. "Watch the puddle, Luke!"

 

[NCFord]

So, a plain black coupling cut half will work? I have two tanks that I am bringing to a welding shop to do my storage
tanks and we were not sure what type of fitting to use.

 

[ewdudley]

So, a plain black coupling cut half will work? I have two tanks that I am bringing to a welding shop to do my storage
tanks and we were not sure what type of fitting to use.

"Forged steel half coupling" is a term of art for a fitting that is manufactured to be like half a coupling.

I guess the only overriding requirement is that whatever you use it needs to be steel, not cast iron. So forged steel couplings (or in a pinch, steel nipple) cut in half would be fine. Check Grainger catalog online to see the distinction between forged steel black iron and cast iron black iron.

 

[maple1]

I picked some 'BI' fittings out of bins at the supplier here, and took those with me to my welder along with my tanks.

He had one of his guys do the work, and home I went with my tanks.

Only found out afterward when I found a couple small leaks on the welds at home when pressure testing with air, that some of those fittings in the bins were cast iron, and some were steel. He dropped by with his portable welder & got me fixed up, but it took a bit of careful welding on his part. So, try to make sure you get steel fittings and not cast iron. In my case, they had both in the same bins - but if you do mistakenly end up with cast, they can be made to work with careful welding by an experienced welder. They all looked the same to me in the bins.

 

[NCFord]

Got it. No plain black couplings. I am going to look at Grainger right now. I am not a welder I just want to have everything
ready to go when I take it to the shop. I guess they should know all this but I have learned to do all the research myself then
have everything the shop needs. Thanks.

 

[NCFord]

What size fittings do you use? I was planning on just using 1 inch, since I am just running 1 inch pex to them.
I also have to cut the holes in the used propane tanks before I take them to the shop. My plan is to fill the tanks with water
then use a hole saw to cut in the proper size hole. Will a hole saw work? I know the metal is about 1/4-3/8 inch thick.

 

[maple1]

I used 1-1/4", since that is what my boiler tappings, loading unit, and existing supply & return headers all were. I think I would match everything to my boiler tappings, as much as possible - or at least everything between boiler & storage.

 

[NCFord]

So, like this... (broken link removed)

have the same thing in galv. as well. it's a litter cheaper

 

[NCFord]

Better Yet this half coupling... (broken link removed)

 

[ewdudley]

What size fittings do you use? I was planning on just using 1 inch, since I am just running 1 inch pex to them.
I also have to cut the holes in the used propane tanks before I take them to the shop. My plan is to fill the tanks with water
then use a hole saw to cut in the proper size hole. Will a hole saw work? I know the metal is about 1/4-3/8 inch thick.

If you're going into the side I'd say use 1.5" so you'll have room for a double-tapped bush that you can use to install a dip tube and a riser to get closer to the ends of the tank (for both ports assuming you're going vertical, or just the return if you're going horizontal).

I cut the holes with a hole saw after the fittings were welded on, made it easy to pressure test with high pressure before cutting the hole.

In the big box market I'm sold on Lenox hole saws, Milwaukee not so much.

 

[NCFord]

Right now I am going ahead with 2 120 gallon propane tanks tied together or 2 250 gallon tanks if I can find one or two in the next
few days. I really want to get some storage soon. I am planning on just putting 4 taps in each tank, 2 near the top and 2 near the bottom. I had not planned on the dip tubes, but I think I will put the bigger fittings on just in case I change my plans.

 

[ewdudley]

Right now I am going ahead with 2 120 gallon propane tanks tied together or 2 250 gallon tanks if I can find one or two in the next
few days. I really want to get some storage soon. I am planning on just putting 4 taps in each tank, 2 near the top and 2 near the bottom. I had not planned on the dip tubes, but I think I will put the bigger fittings on just in case I change my plans.

For short tanks all you need is just one port on the ends of the tank at the apex of each dome, assuming you have room to go vertical. Then you won't ever need dip tubes and 1" would be big enough. (May want to add a 3/4" fitting for temperature well near top of one or both tanks.)

 

[NCFord]

Could I not use one the existing taps for the temp? The one where the propane valve goes in?

 

[Fred61]

I personally wouldn't invest any money in two 120 gallon tanks. It's not enough capacity to make a difference. You will be wasting your money. Look around for something larger. The plumbing costs won't change with larger tanks.

 

[Coal Reaper]

i used cast iron and it was a PITA to get sound welds. one of the pics here shows the top of my tanks. https://www.hearth.com/talk/threads/vedolux-37-install.110669/

 

[maple1]

Definitely the more storage the better. I have 660 gallons & would like to have more. Just haven't figured out how I can get more in the spaces I have. My boiler manual specs to allow 8-10 litres of storage per 1 sq.m. of heated area. For my house, that works out almost exactly (by fluke) to 660 gallons. I think I would tend more to just put in as much as you can - preferrably with enough heat capacity to hold at least the heat that would be produced by a full burn. But there are a lot of variables in figuring that out.

 

[Fred61]

My new rules on storage would be to install enough for batch burning. It's the cat's meow. Of course, that's just as hard to calculate.

 

[NCFord]

I agree more is better. I am looking for 2 250gallon tanks and I think I just found 2 for a good price. Either way it will be
two tanks tied together.
I don't have room for anything bigger than the 2 250 gallon. It has to be the 250 gallon size because I have to go through a
door.
I think anything is better than what I currently have which is like 50 gallons including the boiler and all plumbing.

 

[Fred61]

With 500 gallons, you will at least see a result for the money you spent.

 

[maple1]

My 330 gallon tanks were 30" in diameter. That's what they spec'd, when I did some rough measuring I got 29".

Not sure on your door situation though. They were also 9' long, which makes them a bit cumbersome for tight spaces.

 

[woodsmaster]

Use some cutting oil when you drill your holes.