seackocs

[30boat]

I have to replace several seacocks on my fulmar and have been reading about DZR (dezincification resistant) brass ballvalves,and 316 stainless steel ones.
The latter could be fitted to trough hulls of the same material.I worry about electrolysis with stainless steel when under water.
Any sugestions would be greatly appreciated.
Thanks

N.Santiago

 

[philip_stevens]

As I said in your other posting, put this one on the Westerly newsgroup as well.

regards,
Philip

 

[vyv_cox]

Re: seacocks

I suggest that there is one supremely good material for this application - bronze. Blakes have been manufacturing seacocks in this alloy for years and years and many contributors to this forum have good experience stretching back more than 25 years. Those on my boat show no absolutely no deterioration after 17 years.

On DZR brass - the Royal Navy have been trying to find this for centuries. Whilst there has been some progress, new developments only delay the process, not stop it.

Stainless steel is fine underwater, unless there are crevices present. These can range from scrratches or rough machining marks to threads, mating joints, etc. Crevice corrosion will occur at these points and it may or may not be serious. In practice, everything manufactured will have crevices.

My only rider to all this is that I believe the non-metallic seacocks to be a good product but I have no personal experience of them.