It is a backflow preventer . The first (normal) type simply thread "on"
(female) to the bibb with a standard (~3/4") hose thread.
It has the same thread on the other end (male) to connect the hose.
http://edis.ifas.ufl.edu/AE113
If that is the type, you're OK and can get them at any plumbing supply
place. If its not the standard type pictured in the above URL, then yours
may have a thread and a larger diameter than the standard bibb and the
thread reversed..
Our neighbors have that other type. Its designed to perform the same
function. There is a vinyl/rubber seal inside and that is what is supposed
to 'seal' under pressure and stop water 'leaking' out. When the tap is shut
off, the seal is supposed to release and let the water in the bibb 'out' and
'air' in creating an air gap therefore preventing any chance of backflow.
In yours (and my neighbors) the seal has failed and its not designed to be
replaced inside the larger than normal brass fitting.
The first type can be removed and a hose simply connected to the bibb in the
normal fashion.
The other type has a built in feature that once it's removed, all you have
left on the bibb is a 1" large FEMALE thread to which nothing can be
connected. Its the design of the bibb itself that's the problem, not the
preventer.
That being said, I called all the usual suspects looking for a replacement
for the neighbors 'leaking' adapter: HD, ACE, HH and no one had a clue
what I was talking about..I even called the builder of the home to find out
who the plumber was that put this thing on..no luck. I finally got hold of
a company that had them and sent the neighbor over to get a new one. If
yours is the first type..well, that's it.. if it's the second type, advise
and we'll find out where you can get one in your area.
"David Nebenzahl" wrote in message
s.com...
One of my customers has a weird thing on one of their hose bibs outside: a
large brass or bronze cylinder with male hose threads outboard (presumably
female on the other side), and a series of holes around the male threads.