how to plumb pressurized storage tanks

[DaveBP]

Why do you feel I should not use the ports the way they were designed if the tanks are manufactured for hot water storage? I really dont want to alter or weld on the tanks due to them being ASME pressure vessels. Does the tank have to charge from the top down or is it possible to charge from bottom up and take advantage of the internal baffle for stratification with hot water going out the top? Looking forward to any comments.

I honestly don't understand the design. Doesn't mean it isn't a great tank for some purpose I haven't been able to imagine, I just don't get it.

For wood boiler heat storage I would just use them, as is, putting heat in at the highest port you have and withdrawing the cold return water to the boiler from the lowest port you have.
If you want to preserve the ASME rating for legal or insurance reasons don't do any welding to it. If those ports aren't exactly on the top or bottom I don't see why it wouldn't work anyway. It might function as though it were a slightly smaller tank but they look like rugged tanks. The plumbing schematic on their website might be for a different type of system than your intentions. But then, propane tanks aren't designed to be used as hot water storage tanks, either.

 

[Singed Eyebrows]

Hi Randy, I went out this morning and took some measurments. The tanks stand 7 ft 6 inches from the top to the bottom. The very top port comes out the top of the tank oneand the second top is one foot down from the top. The very bottom port is 23 inches off of the floor but really only 15 inches up from bottom of the tank due to a 8 inch base ring that the tank is mounted on. The second bottom port at 31 inches off of the floor which is 8 inches above the very bottom port. Why do you feel I should not use the ports the way they were designed if the tanks are manufactured for hot water storage? I really dont want to alter or weld on the tanks due to them being ASME pressure vessels. Does the tank have to charge from the top down or is it possible to charge from bottom up and take advantage of the internal baffle for stratification with hot water going out the top? Looking forward to any comments. P.S. I see you are from Milwaukee , Im just out of Green Bay.

My concern was getting hot water to your radiators/baseboard fast enough & the greater the distance between the top ports the longer you will wait. Try em the way the are & if you need to keep the ASME rating you have no choice. They don't need to be ASME in Wisconsin as I was told & I personally wouldn't hesitate to weld couplings in if needed. I don't believe these tanks were designed to be charged with a Termovar etc, even though they are hot water storage tanks. You need to charge from the top down for stratification. The band of hot water needs to move slowly downwards so you don't mix the tanks. We are only 150 miles apart & if in the neighborhood you are welcome see my Atmos install that I am just about to fire up, Randy

 

[Hunderliggur]

Looking at the Hamilton drawings, there is another plugged port on the top of the tank. What size is it? You could probably use this to draw out the hot water for the loads.

 

[jimde]

Thanks for jumping in back in fellas, I checked on the other top port and was suprised. I thought it was just a three quarter inch port like the pressure relief ,but I was wrong. The drawings show that it is a 1.25 inch. If this is true which I will check tommorrow,I think this will make plumbing much easier. Also: thank you Randy for the invite,I didnt realize that 12 inches of tank made that big of difference to the hot water outlet vs inlet, but what is the difference if it is going through a termovar for charging. Im excited if the 1.25 inch will work.

 

[jimde]

I checked and it is 1.25inch. What a relief because I did not want to alter ASME tanks. If I am correct this should make plumbing much easier.