Fixing my SHW heat exchanger

[shaniac]

I have an 80Gal Rheem solaraid tank with the built in heat exchanger that has a cracked female thread drop ear 90 at the bottom. I need to replace the drop ear and I am trying to determine what size I will need. According to Rheem the I.D. of the copper coil is 5/8, but no one at Rheem knows if that mans it is an inside diameter of 5/8th or if it means it is 5/8 copper coil. Either way I only seem to be able to source out a 1/2 inch or 3/4 90 degree drop ear, so I am presuming a 3/4 FIP to 3/4 slip (or C) will slide over the current copper coil. My next step is to pull the broken one off and just compare it, but I was wondering if any of you gurus knew if the ID=5/8 meant it will slip onto a 3/4 slip or not. Thanks in advance, as always.

[ghurd]

In my experience, they mean 5/8".  Whatever that means.

But 5/8" is not compatible with other sizes.  Not compatible to the degree that it seems like they intentionally made it that way.

http://www.gizmology.net/pipe.htm


If it requires some strange size to make a repair, a machine shop should be able to whip up a suitable solderable brass adapter for a relatively reasonable cost.

I have fixed some similar issues by using a brass compression fitting, severely over-tightening it, then soldering the whole mess solid.  Not recommended because it is an un-reversible solution (you only get 1 try, and then pray it works and does not happen again).
G-

[ghurd]

I have questions about the tank.

It has a heat exchanger in the tank, which is isolated from the DHW?  If the solar collector springs a leak, the pressurized potable household water is not spraying out the leak?

It isn't just a tank with 4 in/out fittings?

It looks like 1 question.

It sounds like something my friend is looking for, if the solar can be drain back.
I don't quite follow some of the online data about them.

$2,000 tank.  Ouch!
G-

[shaniac]

Yes, the tank is a Rheem 80 gal w/ built in heat exchanger wrapped around the lower part of the tank. They run about 1800 plus fees, but this was a $150 Craig's list special that was broken upon installation so it was a real find. The water and the glycol mix never come close. I pulled the broken drop ear brass 90 off the bottom of the exchanger loop, and a standard slip 3/4 street end, 90 slid right on to the copper coil, so I am good to go. Next I have a question about the panel setup but I will post that in another subject. I hope this helps someone in the future. Note, the drop ear 90 that was cracked was soldered not only on to the coil loop, but was spot brazed to the side of the tank as well, so it took some HEAT!!!! But it did slide off.