seacocks again

[Spyro]

Sorry to post about this much talked about subject again but the more I read the more confusing it gets.
Quote from another thread
"Proper seacocks - ie Blakes are Bronze and only made in small quantities; Gate valves are BRASS and made in huge quantities for the plumbing market(and should NEVER be used on boats!)
Instead of Blakes you can use a Bronze skin fitting with a Bronze Ball valve for about ¼ the price of a Blakes - and just as good."

If this is the case?
Why are so many chandlers selling ball valves available in brass or bronze and also gate valves in brass or bronze?
I have a gate valve that needs replacing I think its original (24 years old) don't know if its brass or bronze, if its lasted this long why can't I replace with another gate valve?

Ian

 

[dickhicks]

I replied to you earlier from work. Gate valves almost always leak after a while and they are not usually designed for marine work - if they are ALL bronze they will be almost as expensive as Blakes with again a very limited market. Brass valves WILL de-zinctify and eventually fail. Chandleries always sell a range as gate valves are much cheaper and they will always be able to sell some for the really budget conscious boater. Chandleries often don't sell the correct marine items and often know no better.
If your original gate valve has lasted 24 years then perhaps it's bronze - but you might have difficulty replacing it with an all bronze valve(ask the chandlery if he has paperwork Guaranteeing it's Bronze...) I'd be surprised if he has any.
Bronze valves are cast so will have rough cast finish on the outside and are usually a dark bronze colour - Brass valves are usually smooth(although sometimes you cannot tell...) and are usually yellow in colour.
Ball valves have been available recently which are avalable in both bronze and brass - the bronze ones are usually more expensive.
Try <A target="_blank" HREF=http://www.asap-supplies.com>http://www.asap-supplies.com</A> for various ball valves etc. - they stock both types - often called 'dezinctication resistant' ball valves and brass bodied types.
Good luck!

<P ID="edit"><FONT SIZE=-1>Edited by dickhicks on 11/02/2003 23:13 (server time).</FONT></P>

 

[Andrew_B]

My boat is a 34ft 20yr old Hunter Legend fitted with large gate valves that have never leaked.
My previous boat was a 26ft 18yr old Jeanneau fitted with ball valves - they all leaked!
I know in theory that ball valves are better than gate valves but if I ever have to replace any I personally will always go for good quality gate valves.

 

[Plum]

As has already been said by others, the trouble is that for each type of valve there are good types and bad types and telling the difference is not easy. Even some of the so-called bronze gate valves have brass internal parts and it is not possible to tell the difference between a good de-zinc resistant brass from a common brass.

I recommend you do not buy from a chandler, but go to a specialist supplier, like Aquafax, who will sell you dezinc-resistant ball valves. I have been using these now for 5 years will no sign of a problem.

 

[charles_reed]

Real bronze lasts virtually for ever - brass invariably de-zincifies - whether bronze or brass, gate valves are more prone to leaking than ball valves.

I buy my brass valves, of both kinds, from a wholesale plumbers' merchant and replace them every 3 years - it's far cheaper, more efficient and as safe as farting around trying to find, admiralty bronze, navy brass or any of the other cheap alloys they try and pass off - I doubt if anyone makes in anything better than admiralty bronze, which is only a little different (1% tin) from brass!!