Seacock manifold system

[kudu]

I was going to use the "master seacock" as well until I thought about having to service it. How does one accomplish that without heading for dry dock? After getting feedback here, it seems that the seachest idea holds more promise. Each smaller valve could be isolated, serviced and/or rebuilt while still in the water, your thoughts?

[gonzo]

An old but tried way to fix seacocks and valves in the water is to carry plugs. They are also good for emergencies. You can make them out of soft wood or rubber. I think that it makes no difference whether it is a single or several to repair as far as technique is concerned.

[kudu]

Are you familar with the dump valves on recreational vehicle holding tanks? I would like to incorporate the same type of valve at the bottom of the seachest. Doing so, I could stop the water flow coming into it when needed. I could then drain the seachest into a container allowing for seacock service. Atleast that's the plan!

[Raykenn]

Kudo,

Of what material will the seachest be made?

I have seen another verision of a cleanout access on some commercial tugs, but it is in the form of a gasketed flange on a vertical pipe section that acted as a manifold. Similar to what Polarity identified earlier but the one I was looking at was a 12" diamenter and did not project above the waterline. This does require a gasketed cover plate/box to be placed placed over the exterior of the seawater intake to stop water from entering when the system is open, meaning you or a diver has to go over the side.

I also agree with Gonzo concerning plugs. In the past I have attached the plug of proper size to the valve or inlet flange by a lanyard. That way you don't have to go looking for it in an emergency.

The most vulnerable item in the seawater intake system is the connection between the hull and the valve. Whether the valve is connected directly to the hull or via a spool piece, go heavier than the rest of the line. It has to be able to take some abuse.

If I may suggest, be careful about making things too convienient from experience working with boat crews, people tend to forget about things that do not require some periodic inspection and maintenence.

Good luck with your project.


Regards

Raykenn