Best seacock for saltwater intake in head

[Australiandad]

I’ve replaced all my fittings with true designs and they work a treat.

[phydeaux]

Marelon works is the plan - no corrosion, and easy to keep lubed. Check www.forespar.com, and well as West, Fisheries and I think Defender.

[Scout 30]

Originally Posted by Australiandad

I’ve replaced all my fittings with true designs and they work a treat.

These look great but I'd use the load bearing collar with it.

Load Bearing Collars | TRUDESIGN

[vyc2014]

Originally Posted by kenbo

I'm a little surprised that Forespar's marelon seacocks haven't been mentioned. Non corrosive and typically non binding they are a very viable choice.

We had marelon seacocks and they got scored badly by opening and closing with barnacles in the thruhulls, and they were never water tight again.

[Kudawudashuda]

Best sea cock is no sea cock. After 40 years of having my head down repairing too many boat toilets (one brand new) I got a port-potti and haven't regretted it for one second. Best bit: rowing to shore not having to wonder if you have turned your drain cocks off.

Incidentally, got rid of gas too. Luxury!

[Davo1404]

I have changed all my valves to the "Trudesign" ones. They are US Coastgard & Lloyd's of London approved. I have been living aboard for 12 years & fitted these valves 3 years ago. Very happy with them, and the manufacturer is very helpful when you phone or email them.

[Davo1404]

Originally Posted by vyc2014

We had marelon seacocks and they got scored badly by opening and closing with barnacles in the thruhulls, and they were never water tight again.

Unfortunately barnacles will definitely damage any type of material.

[Morph]

I fitted marelon through hulls in my 40' cat and they were amazing-beautiful bits of kit. No corrosion to worry about (especially where you can't see it), took huge amounts of abuse, never had a problem with barnacles growing inside. Pricey but relatively easy to fit. Would never have anything else.

[masonc]

Originally Posted by old frog

In my opinion, it depends upon the boat, boat construction, sea valve location within the boat, the boat's future intended usage, the boat's electrical complexity, and where the boat it moored and that environment, etc. There is no one one "best" sea cock.

Personally, & assuming the boat is FRP, I prefer the traditional flanged bronze coned sea cock (several manufactures) positioned in the boat so that it is easily accessible & serviceable. When installed via monel bolts, bolted to the hull skin (w or w/o the through hull) properly bedded to the hull, these will last almost for ever. I am also of the opinion that they are the strongest impact resistant valve installation & most forgiving vis-a-vis internal abrasion as they can be serviced.

However, as the above boat becomes more electrically complex (Ie. bonding systems &/or moves into a mooring environment where the is a probability of stray current fields within the area/mooring basin, (especially if the boat has a full bonding system) I personally believe the advantage shifts to one of the dielectric composite valve systems. As the suspended abrasives (ie. sand, etc.) in the water increases, I am of the opinion that the advantages begin to shift away. If the boat is wet moored in an area subject to freezing and the sea valve is one that must remain open (ie: cockpit drain), the advantage shifts back to the "traditional" bronze valve.

While I am not a fan of the ball valve mounted on solely on a threaded through hull (assuming proper thread compatibility & thread engagement), I am of the opinion that the advantage shift to them when the valve is located in a restricted area where it is not easily serviced (as is so common on most production boats) and there is nothing in that space that could shift & place excessive loads on the valve. The advantage of the ball valve is that it requires little maintenance & has a compact size so that it is easy to remove & replace should it develop problems.

All valve have their merits & issues. All, like everything on a boat, require periodic maintenance & inspection.

Don't get me started on the above water line valves. IMHO, the plastic though-hull above the waterline without some method or valve to close the hull penetration when the through hull fails is an problem waiting to happen.

Just my $.02.

How would a valve seal if the through hull fails? I don't understand that comment.

[OOTB2]

Originally Posted by Davo1404

I have changed all my valves to the "Trudesign" ones. They are US Coastgard & Lloyd's of London approved. I have been living aboard for 12 years & fitted these valves 3 years ago. Very happy with them, and the manufacturer is very helpful when you phone or email them.

I am also a fan of "Trudesign" valves and skin fittings, as aptly posted earlier the NZers have nailed it![emoji41]

[OOTB2]

Recent replacement of corroded SS/BRONZE BALL VALVE with TRUDESIGN, done in 1 tide cycle (HT-HT) careened on a beach. Yeah for shallow draft catamaran!

[HopCar]

Originally Posted by masonc

How would a valve seal if the through hull fails? I don't understand that comment.

A properly installed flanged seacock is fastened and sealed to the hull. It would continue to function if the thru-hull fitting were removed.