Gary, it takes more than two dissimilar metals in an electrolyte
(sal****er) for galvanic action to occur. The two metals must be
connected electrically, usually by a wire. So unless your copper and
brass fittings are wired together, which obviously they should not be,
they will not generate galvanic currents.

As Roger has pointed out, the brass may be self-corroding.

Chuck




Gary wrote:
My boat has a tee off the sal****er cooling intakes that can act as an
engine driven bilge pump. The tee is copper pipe with the hoses coming
up from the thru hulls. On the leg of the tee is a brass valve that has
a hose that reaches down into the bilge for pumping.

My problem is the corrosion from galvanic action between the copper tee
and the brass valve that controls the bilge suction hose.

Can anyone tell me how to stop the corrosion of the valve? The one I
have in my hand is almost completely pink because the zinc has
completely dissolved.

Ideas?

Gary