Seacocks

[tyce]

I currently have my engine seawater intake valve off as i found the brass water strainer connected to it had a serious case of dezincification and was hanging on by 1 1/2 threads (phew!)
The through hull fitting is made of bronze or a dzr brass and is original, now the valve is off i can see its in very good condition.
The valve however is stainless steel which initially i thought may be the cause for the dezincification of the strainer due to dissimilar metals, however when i look at all the other inlets on the boat they have the same bronze / dzr with thru hull with a ss valve setup and they look fine.
So is there actually an issue with stainless and bronze / dzr and was the failure down to the strainer being made out of standard brass?
All input much appreciated.

 

[Laurie]

have you thought of Marelon..............?

 

[Tranona]

Replace it with a plastic strainer above the waterline - see the Vetus catalogue for schematics of installation. www.vetus.com there are other suppliers of similar strainers.

 

[vyv_cox]

How do you know it is stainless steel? Are you sure it is not a chrome plated brass valve? These typically have an electroless nickel plated ball, which also looks like stainless steel.

Dezincification has nothing to do with galvanic couples, it occurs to brasses exposed to seawater.

 

[venntim]

Slight thread-jacking as I have a similar issue.

I'm in the process of replacing my old thru-hulls and valves with new ones. So far I've been unable to find recessed stainless thru-hulls . I'm wondering whether there is a corrosion risk if I combine a bronze (recessed) thru-hull with a stainless steel valve. Any insights? Thanks!

 

[macd]

I'm wondering whether there is a corrosion risk if I combine a bronze (recessed) thru-hull with a stainless steel valve. Any insights? Thanks!

Bronze or DZR hull fittings with stainless ball valves are pretty commonplace.

Check out this recent thread: http://www.ybw.com/forums/archive/index.php/t-273121.html
You'll find plenty of others with a Google search within domain ybw.com