What causes brass piping to disintegrate like this?

[Jadnashua]

You seem to be missing the point...when you replace the tires on your car, you can buy retreads, or a premium new tire. They both work, the retread saves some money. Neither is 'wrong'. When a builder is putting up a house, he is looking at the bottom line and if things will get beyond his home warranty period, not (generally, there are exceptions) having it work for a lifetime. Same thing with the choice of appliances installed.

When it comes to the service industry, a good (IMHO) professional would be looking at longer term since he's looking for referrals and return calls for other work you may want done. Plus, the difference in materials costs is not much when you look at the labor costs. Tract homes, not so much, since they generally don't pay the same as an independent you might hire.

 

[Asktom]

I assume it is me you believe to be missing the point, but actually we just disagree. The failure occurred at the point where two dissimilar metals joined, not where the nipple met the galvanized fitting in the wall. In my opinion using a brass nipple amounts to switching to white wall tires, no better quality, just prettier. Is brass better than galvanized?, sure. Change the whole system to brass and you have something special. Use a brass nipple and you have pushed the point of contact between dissimilar metals from outside the wall to inside the wall. Will that be a problem?, probably not. Is it an improvement?, not in my book. Either will work. Thus, we disagree.