Extrol Thread adapters?

kcopp

Does anyone know how I can adapt over the Straight threads from one of the Zilmet style flat tanks that you see on many of the combi boilers out today? Rinnai, Embassy and Bosch have these built in to the units. Often replacements are not easy to get fast and generally they are much more expensive than a standard #30 Extrol tank. I would love to be able to have the proper metric adapter to go to the 1/2" NPT male by 3/4? BST? thread....
Sorry don't know how this ended up in steam....

hot_rod

That should be a 3/4 nut, most Euro tanks are 3/4 BSP straight thread.

Get a 3/4 X 1/2 brass bushing. Drag a file across it or run it on a belt sander to get a flat surface.

A US expansion tank will fit inside the bushing, or pex adapter to a remote location.

A fiber washer from a auto parts store, a fat o-ring, or a washer hose gasket is workable, a bit too large.

Hilly

What size is the copper? Could you cut the bend off and make a new adapter connection on the straight portion? If you are trying to avoid putting in heat in that area you do have the option of push-fit, press-fit, compression, flare...

kcopp

That pix was just to illiterate what I was asking for.
I am asking because I want to replace the standard Zilmet tank on a Rinnai w/ a more robust Amtrol radiant tank.
thanks.

hot_rod

Are the zilmet tanks failing prematurely? It is supposed to be a good quality tank. I think Zilmet USA stocks those flat tanks

kcopp

Well there is a story there....
I have had many in an apt complex waterlog.
Each building has 4 apts. 4 zones. 1combi boiler w the built in tank.
15 units
Each really needs a bigger tank. They usually go w/in 2 years. Some times I had just left the old tank in line and add the new tank outside the unit attached to the system piping.

I can get new tanks they are just 3 times the cost of a Std #30 extrol.

hot_rod

I think you are correct, that many failures indicates an undersized tank. Maybe they calculate a system volume, or more likely they find a tank that fits inside the jacket

Move it outside the "box" upgrade to a #30 size.

The adapter method I showed will get that copper connection to 1/2 FIP, take it from that.

I'd guess that copper to be a 16mm (.629) a tad bigger than 5/8.
If you have an expander tool you can fudge a 1/2" copper fitting onto it.

SWEI

The SX Series floormounts do cost a bit more, but still an order of magnitude less than an AX. You could always parallel some EX-30's...