Replacing Gate Valves

Gate valves on a boat are a bad plan. They are often fitted where space is tight and conventional seacocks may not fit, but they are prone to seize and to get blocked by debris. Blakes would be the ultimate solution, but they are expensive. However, properly fitted and maintained, they should last. The ball valve types are cheaper, but I wouild be wary of the plastic types, which can become brittle over time and may break off with potentially catastrophic results.
 
We have a gate valve for the sink.

Tip I was given was don't push it hard up against its stops - either open or closed . When open always back off a half turn. Seems to avoid getting jammed one way or another.
 
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Tip I was given was don't push it hard up against its stops - either open or closed . When open always back off a half turn. Seems to avoid getting jammed one way or another

[/ QUOTE ] Yes sound advice and standard practice on industrial installations with gate valves. either opening or closing just back off a fraction. Does not have to be as much as half a turn.

Gatevalves operated now and then should sieze up no more than seacocks or ball valves.
 
Just a follow up to my original post. With a Blakes or ballvalve type seacock, the lever position gives clear indication of whether the cock is closed or open. Harder to spot with a gatevalve. Any disciple of boat mechaics guru Nigel Calder will quote from the great man's heavyweight tome on boat maintenance: "Gate valves have no place in a boat."
 
Re your two sink seacocks (gate valves?) seized in the open position - definitely bite the bullet (for peace of mind, spend piece of wallet) and go for proper Blakes seacocks, or proper ball valves.

Or, for even more peace of mind, take out the skin fittings, glass up the holes, and just run the hoses from the sink drains into a couple of portable water containers fitted under the sinks.
Two less holes below the waterline to worry about then!
 
YES

And do not be tempted by ball valves; either. I had to replace a pair when the nylon seatings for the s/s balls swelled and froze them. 100% Blakes, now...
 
Re: YES

I have mainly blakes, but the couple of ball valves I have (above the waterline) are stainless ones with teflon seats and, most importantly, stainless handles! The plated ones, rust quickly and have no place on a boat, they are also plumbers type, get the marine ball valves! Mine are Italian.
 
Re: YES

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And do not be tempted by ball valves; either. I had to replace a pair when the nylon seatings for the s/s balls swelled and froze them. 100% Blakes, now...

[/ QUOTE ]Not sure that I agree with your suggestion that ball valves are no good. Blakes might be the Rolls Royce solution, but good quality ball valves are fine. Besides which we have 14 though hull fittings and it would cost us a small lottery win to replace them all with Blakes!
 
Re: YES

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Blakes might be the Rolls Royce solution, but good quality ball valves are fine. [

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Agree entirely. DZR ballvalves have been fine for 12 yrs without attention, whereas the Blakes do need regular attention. All my experience of gate valves though has been bad.

Vic
 
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Simple question, having had problems with gate valves seizing either open or shut should I replace them with Blakes seacocks?


Many thanks

[/ QUOTE ]Gate valves often disintegrate inside. The internal metal dissappears under electolytic action. They have no place on a boat.
 
Gate Valves - Suitable for marine use????

Gate valves are normally made from ordinary brass. - I am not sure I would want them on my boat - seizing up may be one thing, but de zincification is entirely another matter - and would result in the boat sinking if not found in time. IMHO they have no place on a sea going boat
 
Changed all my gate valves to ball valves for this very reason (plus they are MUCH quicker to operate). Having said that I have one ball valve which is pretty stiff to operate! Space for the handle also was a problem for one of them.

Do make sure you get good ones if you change.
 
Re any ball valves that have to (by necessity) be left on all the time, such as those on cockpit drains - it is a good idea to work them regularly, ie turn them off and on a few times, to help prevent crud building up inside and possible seizure.

I am amazed how so many quality bronze housing ball valves are supplied with zinc plated steel handles which invariably rust away very quickly. As was mentioned earlier, it would be much better to get ball valves with S/S handles.
 
I don't think I could justify almost £100 for a valve. I replaced 3 gate valves with ball valves 4 years ago. They look good as new and operate fine. I will give them another years service then replace again. They are very easy to change and cost a fraction of what Blakes cost.
Also with replacement ball valves hopefull you should be able to screw them directly onto the skin fitting that you already have.
 
I asked about ball valves here about 4 months ago. As a result I found out that my existing ones were brass, and I've now bought stainless ball valves from ASAP, which I will fit before the boat goes back in the water. The general advice was along the lines of 'why risk a boat worth £X000's for the sake of saving a tenner'. Personally, I can't argue with that (even though X, in my case, is only about 4).
 
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