Sea Water manifold

[rjcoles]

I need to either increase the number of thru-hull fittings or fit a manifold arrangement for the supply of sea water to the fridges etc, looking this up on the web I came accross the term "Sea Chest" as used in ships. This sounds just what I need but how to put it into practice on a yacht? Any ideas?

 

[daveyw]

Think you just need one big skin fitting with a master valve. After the valve you can have a filter then after the filter fit a manifold with the required number of off takes, individually valved. Need to make sure the master skin fitting is big enough to supply all your off takes. On ships they have port and starboard sea chests and high and low ones. They change to high ones when in shallow water to avoid sucking up crud from the bottom.

 

[TradewindSailor]

There is a potential problem with the arrangement : if it is easier for an appliance on one leg to suck the water out of another appliance on another leg rather than to suck seawater from the through-hull, it will do just that. In other words: your watermaker could be sucking air from the refrigerator cooling water pipe, rather than suck seawater.

The answer may be to install one-way valves if this happens.

 

[whipper_snapper]

There is a potential problem with the arrangement : if it is easier for an appliance on one leg to suck the water out of another appliance on another leg rather than to suck seawater from the through-hull, it will do just that. In other words: your watermaker could be sucking air from the refrigerator cooling water pipe, rather than suck seawater.

The answer may be to install one-way valves if this happens.

I agree that may well be necessary if you try to squeeze multiple uses from one skinfitting. But then you end-up with a bunch of horrible plumbing with multiple connections below the water line or horrible loops and yards of pipes and clips.

My strong advice, having been there, is to simply fit additional skin fittings, or else you must go the whole hog and fit a freaking great sea-chest. Many people seem to be paranoid about extra holes in their boat, but a properly fitted sea cock is perfectly secure and usually safer because of the reduced number of connections.

 

[vyv_cox]

I agree that may well be necessary if you try to squeeze multiple uses from one skinfitting. But then you end-up with a bunch of horrible plumbing with multiple connections below the water line or horrible loops and yards of pipes and clips.

My strong advice, having been there, is to simply fit additional skin fittings, or else you must go the whole hog and fit a freaking great sea-chest. Many people seem to be paranoid about extra holes in their boat, but a properly fitted sea cock is perfectly secure and usually safer because of the reduced number of connections.

I agree entirely. Skin fittings are completely reliable and you can locate the new one where it needs to be. Incidentally I read recently that the Starlight 39, a highly desirable boat in most people's view, has 17 skin fittings!