Mixing Stainless Steel and Brass

I have been eyeballing a lot of diferent all grain setups over the last two weeks and have noticed that many people with stainless steel kegs serving as a tun or kettle are having stainless steel fittings welded on to their kegs, then attaching to it a brass fitting. Doesn't this cause leaks and such? I have always been told that since the two metals expand at differing rates that they would not maintain a tight seal.

jw

I recently purchases a Keggle from Sabco. They sell both SS and brass ball valves. When I asked why SS was supposed to be better he (Dan) stated that some people think that you get a brassy tasting beer if you use brass fittings, He stated that was not true. I bought the brass ball valve franky because it was cheaper. It came with teflon tape wraped arount the threads. I've run a 90 minute boil and there was no sign of leakage. I've tasted the beer and there was no brassy taste that I could detect. Maybe SS lasts longer. I'm sure there are other opinions.

In the temperature ranges for homebrewing, differential expansion just isn't a problem. In all my years the only leakage problems I've had is in mugs, they all seem to have holes in them .

I had thought that the worry was that the brass has lead in it?

I'm in the process of converting/building some equipment, and this thread caught my interest. I Googled and found tons of information. From what I read, it seems as though 15 ppb is the recommended maximum lead concentration in drinking water. A *ton* of information points out that almost all faucets in the home are made of brass, as well as numerous fittings in various parts of commercial water systems.

It seems as though we are constantly exposed to it, and your brew water is already "leaded". The concentration of lead is a function of leach time, so I guess that the little brass surface area in the spigot for an hour or two is very negligible in the big picture.

Edit:
Found this comment at http://www.xb-70.com/beer/3_tier/:

Removing Lead From Brass

A small amount of lead is added to brass to make it easier to machine, and this can be removed from the surface of your fittings by soaking the brass in a 2:1 mixture of white vinegar and hydrogen peroxide. Soak until the brass takes on the appearance of dull gold (5 to 15 minutes). If the solution starts to turn green, replace it. This process is probably not necessary, but it makes me feel better and it makes the brass look really nifty. (Source: John Palmer.)

I could never drink a stainless steel and brass drink...too hard on the glass...

But then again...is that shaken or stirred...?

i understand the concentration is low, but i guess i'm just concerned about those details...