Replacing galley gate valves

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steve yates

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The seacocks for under my longbows sink are gate valves, which I want to replace. Blakes are my definite favourite when it comes to seacocks but expensive. I was looking at trudesign when I came across Groco bronze valves. At £30 each its a great price but sounds too good to be true.
Anyone got any experience of them? If anyone else has replaced gate valves in the galley what did you swap too and are you happy with it?Thx.
 
No firsthand experience, but the composite seacocks have been around for a ggod while now and are well proven. We will only fit composite seacocks on our vessel as we are replacing all as part of the refit.
 
steve yates said:
The seacocks for under my longbows sink are gate valves, which I want to replace. Blakes are my definite favourite when it comes to seacocks but expensive. I was looking at trudesign when I came across Groco bronze valves. At £30 each its a great price but sounds too good to be true.
Anyone got any experience of them? If anyone else has replaced gate valves in the galley what did you swap too and are you happy with it?Thx.
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Listen to what Vyv Cox will have to say but DZR / CR brass will be adequate. ASAP supplies have DZR ball valves with DZR balls and stainless steel handles.
 
I had not come across Groco valves before but checking their website they look pretty good. Bronze body, stainless steel ball, grease nipple. If anyone imports them at the price you quote I would have them.
But otherwise, as has been said, DZR easily obtainable, not expensive and excellent performance.
 
vyv_cox said:
I had not come across Groco valves before but checking their website they look pretty good. Bronze body, stainless steel ball, grease nipple. If anyone imports them at the price you quote I would have them.
But otherwise, as has been said, DZR easily obtainable, not expensive and excellent performance.
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About twice the price of DZR but a bit cheaper than Mastrani bronze but cheaper than Trudesign (3/4")
 
Replacing aged thru hulls is not a difficult job.

I cut a slot into an appropriately sized socket so I could grip them to undo and do them up on my own from inside.
 
vyv_cox said:
I had not come across Groco valves before but checking their website they look pretty good. Bronze body, stainless steel ball, grease nipple. If anyone imports them at the price you quote I would have them.
But otherwise, as has been said, DZR easily obtainable, not expensive and excellent performance.
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But the Groco ones being sold here https://foxschandlery.com/products/groco-bronze-in-line-ball-valves have a brass body. The C83600 material they quote has 4 to 6% zinc and no Arsenic that DZR brass contains. Would C83600 be as good as DZR?
 
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PabloPicasso said:
Replacing aged thru hulls is not a difficult job.
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No one claimed that it is, but it is additional time/effort and cost quite likely not necessary.

Replacing a gate valve with a ball valve just requires one to be unscrewed and the other screwed on in its place.

If I remember correctly, Tru-design and other laminate construction fittings use a different connecting thread to the standard sized BSP ones used with conventional metal bodied valves, therefore replacing the valve also involves replacing the thru-hull, which in the case of laminate fittings like Tru-design require a larger sized hole in the hull (I know because I've done it) as the body is necessarily thicker than standard metal fittings. The Blakes seacocks are a one piece combined seacock and thru-hull. I can't remember for certain but suspect they might require a larger or different shaped hole, they do, though, require additional holes for the bolts that secure the external plate to the internal body.
 
Plum said:
But the Groco ones being sold here https://foxschandlery.com/products/groco-bronze-in-line-ball-valves have a brass body. The C83600 material they quote has 4 to 6% zinc and no Arsenic that DZR brass contains. Would C83600 be as good as DZR?
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The material is bronze, not brass. Bronze can be quite difficult to cast, as the tim phase oxidises quite rapidly. A small amount of zinc, about the amount you describe, is added as an anti-oxidant, allowing the zinc to oxidise preferentially.

Bronze has excellent resistance to corrosion by seawater. Not quite as good as the 400 year old gunmetal cannon (10% tin) that are recovered from the seabed but modern versions with less tin will outlast the boat.
 
LittleSister said:
No one claimed that it is, but it is additional time/effort and cost quite likely not necessary.

Replacing a gate valve with a ball valve just requires one to be unscrewed and the other screwed on in its place.

If I remember correctly, Tru-design and other laminate construction fittings use a different connecting thread to the standard sized BSP ones used with conventional metal bodied valves, therefore replacing the valve also involves replacing the thru-hull, which in the case of laminate fittings like Tru-design require a larger sized hole in the hull (I know because I've done it) as the body is necessarily thicker than standard metal fittings. The Blakes seacocks are a one piece combined seacock and thru-hull. I can't remember for certain but suspect they might require a larger or different shaped hole, they do, though, require additional holes for the bolts that secure the external plate to the internal body.
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I always thought Tru Design were BSP threads
Trudesign Compact Ball Valves | Tek-Tanks
 
Boathook said:
I always thought Tru Design were BSP threads
Trudesign Compact Ball Valves | Tek-Tanks
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That may well be so. I did express uncertainty on that particular issue.

I definitely remember that the skin fitting part's external diameter and clamping collar thread is greater than the standard metal BSP fittings of the same nominal size (the wall of a laminate fitting has to be thicker than the metal equivalent while maintaining the same nominal internal pipe diameter), as I had to enlarge the holes in the hull to accommodate them when replacing original nominal 1 1/2" deck drain thru-hulls.
 
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LittleSister said:
You say you want to replace the seacocks, but your suggested replacements involve replacing the through-hull fittings, too.

I'd there's nothing wrong with the existing thru-hulls, why not just replace the gate valves with ball valves? A much quicker, easier and cheaper job.
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Thats what I was planning to do, sorry I probably wasn’t very clear in that.
So I’m looking at either the groco bronze gate valves or the maestrini ones. Both of them have a chrome plated brass ball inside a bronze body, though the maestrini one says it has a brass shaft and packing body. I think the existing throhull is bronze, but was thinking it would be wise to replace it at the same time to ensure the skinfitiing and seacock match up exactly.
I’ve ruled out the marelon ones for taking up too much space and potentially getting broken by locker contents sliding around.
 
steve yates said:
Thats what I was planning to do, sorry I probably wasn’t very clear in that.
So I’m looking at either the groco bronze gate valves or the maestrini ones. Both of them have a chrome plated brass ball inside a bronze body, though the maestrini one says it has a brass shaft and packing body. I think the existing throhull is bronze, but was thinking it would be wise to replace it at the same time to ensure the skinfitiing and seacock match up exactly.
I’ve ruled out the marelon ones for taking up too much space and potentially getting broken by locker contents sliding around.
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I'm a bit foxed that you refer to the Groco valves as gate valves then say both that and the Maestrini are ball valves. Ball valves good. Gate valves not so good as seacocks (but OK for 'internal' water supply etc.). Ball valves have a lever that just needs turning 90° to open or close, gate valves have a circular knob/wheel handle that needs multiple rotations to screw the gate all the way up or down (recommended practice with these is once it bottoms or tops out, turn it slightly back again so that it is less likely to jam fully open or fully closed).

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There should be no problem with the threads matching the existing thru-hulls.

Re the existing thru-hulls. Have a look at them. Are they perhaps pink on the exterior face and inside the pipe (once any fouling or antifouling removed)? Pink indicates dezincification, but it is typically surface only. If pink, try cleaning off surface with fine abrasive paper. It will probably be proper bronze or brass colour underneath, in which case they are sound and you can leave them in place. If it is pink to any depth then replace them, as dezincification (unless just shallow surface only) seriously weakens them. Also replace if they are seriously pitted.

Yes, the Tru-design are significantly bulkier, and especially taller, than standard metal fittings. I think they are strong, but the unusual height means there will be a far greater leverage if anything hits them, and they may well be more in the way of things that might potentially fall against them.
 
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