I'm looking for a overview of correct plumbing for thru hull discharge. Boat was original set up for a bladder tank pump out only for lake use. I have the black water schematic but am unsure if the sink pump will pump thru the thru hull fitting under galley sink. javaken@aol.com
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I'm a bit confused...
What galley sink pump? Unless the galley sink drains into a sump (unlikely), the only galley sink pump should be the fresh water pump...water going down the sink drain should get out the thru-hull without a pump. There'll always be water in the drain line to the water level. If your boat was originally plumbed to send both gray and black water to the tank, it must have been on Lake George NY or on an inland lake in NH. Although it's done to save space, gray and black water shouldn't be combined in the same tank, nor should there be any common plumbing in the two systems. So I'm assuming you're trying to re-plumb the boat to send only the black water (toilet waste) to the tank--and maybe add a y-valve and pump to dump the tank at sea (but that pump shouldn't have anything to do with the galley drain)...and send the gray water from the sink directly overboard. If that's not what you're doing, it's what you should do.
I also suggest you replace the bladder with a rigid tank. If it's not a vented bladder, you'll have to either install a vent or replace it with a vented tank if you can't add a vent...'cuz CG regs require that all waste tanks be vented to the outside of the boat.
What galley sink pump? Unless the galley sink drains into a sump (unlikely), the only galley sink pump should be the fresh water pump...water going down the sink drain should get out the thru-hull without a pump. There'll always be water in the drain line to the water level. If your boat was originally plumbed to send both gray and black water to the tank, it must have been on Lake George NY or on an inland lake in NH. Although it's done to save space, gray and black water shouldn't be combined in the same tank, nor should there be any common plumbing in the two systems. So I'm assuming you're trying to re-plumb the boat to send only the black water (toilet waste) to the tank--and maybe add a y-valve and pump to dump the tank at sea (but that pump shouldn't have anything to do with the galley drain)...and send the gray water from the sink directly overboard. If that's not what you're doing, it's what you should do.
I also suggest you replace the bladder with a rigid tank. If it's not a vented bladder, you'll have to either install a vent or replace it with a vented tank if you can't add a vent...'cuz CG regs require that all waste tanks be vented to the outside of the boat.Grey water plumbing setup
Peggy, Yes, boat was in NH on Lake Winni...-There is a separate rigid tank for head & I plan on installing a macerator with lockable Y valve. Head and galley sinks have a switch which activates a jabsco pump going into a vented bladder. I think I understand what you are saying but will head sink also gravity drain all the way to thru hull under galley drain assuming I bypass grey water bladder tank? Thanks for all your help! Great book by the way!
Peggy, Yes, boat was in NH on Lake Winni...-There is a separate rigid tank for head & I plan on installing a macerator with lockable Y valve. Head and galley sinks have a switch which activates a jabsco pump going into a vented bladder. I think I understand what you are saying but will head sink also gravity drain all the way to thru hull under galley drain assuming I bypass grey water bladder tank? Thanks for all your help! Great book by the way!
Aha...now I get it..
You should be able to remove the bladder and the pump (use it to dump your black water tank) and connect the sink drains to thru-hulls. Your galley sink should have no problem draining by gravity. However, I suspect from what you've said that the distance from the head sink to the galley sink thru-hull may be too far, or take too convoluted a route, to use the same thru-hull for both the galley and head sink drains. The simplest solution for that would be to use the same through-hull for head sink drain that the toilet intake uses..tee 'em together. This will also give you the ability to flush the sea water out of the sanitation system by closing the thru-hull, filling the sink and flushing the toilet. Glad you find the book useful!
You should be able to remove the bladder and the pump (use it to dump your black water tank) and connect the sink drains to thru-hulls. Your galley sink should have no problem draining by gravity. However, I suspect from what you've said that the distance from the head sink to the galley sink thru-hull may be too far, or take too convoluted a route, to use the same thru-hull for both the galley and head sink drains. The simplest solution for that would be to use the same through-hull for head sink drain that the toilet intake uses..tee 'em together. This will also give you the ability to flush the sea water out of the sanitation system by closing the thru-hull, filling the sink and flushing the toilet. Glad you find the book useful!
Thanks Peggy!
That makes sense, Ps: I always use fresh wate in head-keeps odors down quite a bit. Thanks again for your help!
That makes sense, Ps: I always use fresh wate in head-keeps odors down quite a bit. Thanks again for your help!
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