Need help with head and hoses

[George DuBose]

At the beginning of this thread by Navdi, there is a sketch that I have a problem with. Where does the seawater come into the toilet. I only see a hose leading to the Y valve from a "closed" seacock and a hose leading from the Y valve to the toilet and a hose leading from the Y valve to the holding tank.

Where does the water come from to flush?

[Knotical]

Originally Posted by HopCar

You probably have a threaded fitting in the tank that has a hose barb screwed into it and the discharge hose is clamped onto the hose barb. You want to put a valve between the tank and the hose so you can close the valve and remove the hose without the tank dumping it’s contents into the bilge.

Makes sense, thank you.

[Knotical]

Originally Posted by George DuBose

At the beginning of this thread by Navdi, there is a sketch that I have a problem with. Where does the seawater come into the toilet. I only see a hose leading to the Y valve from a "closed" seacock and a hose leading from the Y valve to the toilet and a hose leading from the Y valve to the holding tank.

Where does the water come from to flush?

Hi George, I didn't draw the raw water intake in my initial sketch as my questions were not related to intake and I didn't want to make the sketch any busier.

If you look at a subsequent post of mine (#12) I have attached a photo from the owner's manual that shows the intake seacock, it is about a foot to a foot and a half forward of the holding tank and head sink drain discharges.

[Nicholson58]

Most likely the stink is from long term permeability of old hose. Replace it all. I love the Raritan for it permeability rating and very high flexibility. Keep the Y but make sure there is an adequate lock on it or an on water spot inspection will cost you.

Most tank vents are too small and may have a bug screen. The screen is usually covered with spider webs. Our vent is 1/2 inch bronze through hull, center and high on the transom. NO SCREEN

Off shore boats empty by gravity drain if it’s set up that way or you need an aux pump. We have a deck fitting to a hose and manual poop pump. Electric permanent installation would be nice. Make sure all is in compliance (lockable) for your cruising location.

[Mike Banks]

Your tank is a bad design, it looks like a water tank which has been converted poorly into a holding tank. If that hose to your outlet fails, the entire contents will be in your bilges--never to be entirely removed short of stripping your vessel and using high pressure hoses to get rid of any stink.

A proper sullage tank has the outlet in the tank top connected to a pipe leading to the floor of the tank and terminating just above it, ideally in a shallow sump built into the sole of the holding tank but that is not always possible.

The pipe passes through a flange mounting plate which secures to the tank top using studs or captive bolts welded into the tank top before it is fitted to the tank. Failing that, it may be secured using threads and collars on the pipe itself, access to the lower collar or pipe being made via a separate inspection port also pre-positioned in the tank top.

To the top of this discharge pipe above the tank is a junction fitting, the side outlet goes to a suction pump of the diaphragm plunger type on board and mounted above the tank top, the other goes to the seal-able in-deck outlet fitting for offshore black water removal via a truck with its own extraction pump.

The side outlet to the diaphragm pump allows the pump to suck out the contents of the tank for deep ocean discharge through a sea cock, mounted below water line.

I would get rid of that hand-pump head and replace it with an electric macerating system. It is SO much better to have fine particulate mixtures in the black water instead of one filled with fragments of paper and other lumps and objects etc. Cleaning out a clogged black water system is about the worst job one can have below decks.

The hose from your heads with its macerating pump passes to a siphon breaker at the deck level, and the discharge d=side of this passes into the sewage tank also through a flanged fitting in the tank top. I also had a float switch mounted here, to tell me if the tank was full. It connected to an audible alarm as well as a red light.

[Knotical]

Originally Posted by Nicholson58

Keep the Y but make sure there is an adequate lock on it or an on water spot inspection will cost you.

I have a small string attached to the Y-valve but it's not connected to anything, maybe I will just tie it to something so it doesn't turn the other way. The discharge seacock is stuck in closed position anyway so all it will do is make the waste sit in the hose..can I show the inspectors the closed seacock if I ever get boarded?

Cheers.

[Knotical]

Originally Posted by Mike Banks

Your tank is a bad design, it looks like a water tank which has been converted poorly into a holding tank. If that hose to your outlet fails, the entire contents will be in your bilges--never to be entirely removed short of stripping your vessel and using high pressure hoses to get rid of any stink.

A proper sullage tank has the outlet in the tank top connected to a pipe leading to the floor of the tank and terminating just above it, ideally in a shallow sump built into the sole of the holding tank but that is not always possible.

The pipe passes through a flange mounting plate which secures to the tank top using studs or captive bolts welded into the tank top before it is fitted to the tank. Failing that, it may be secured using threads and collars on the pipe itself, access to the lower collar or pipe being made via a separate inspection port also pre-positioned in the tank top.

To the top of this discharge pipe above the tank is a junction fitting, the side outlet goes to a suction pump of the diaphragm plunger type on board and mounted above the tank top, the other goes to the seal-able in-deck outlet fitting for offshore black water removal via a truck with its own extraction pump.

The side outlet to the diaphragm pump allows the pump to suck out the contents of the tank for deep ocean discharge through a sea cock, mounted below water line.

I would get rid of that hand-pump head and replace it with an electric macerating system. It is SO much better to have fine particulate mixtures in the black water instead of one filled with fragments of paper and other lumps and objects etc. Cleaning out a clogged black water system is about the worst job one can have below decks.

The hose from your heads with its macerating pump passes to a siphon breaker at the deck level, and the discharge d=side of this passes into the sewage tank also through a flanged fitting in the tank top. I also had a float switch mounted here, to tell me if the tank was full. It connected to an audible alarm as well as a red light.

I hear you, Mike. I understand it is not ideal but I have to live with it, and the discharge hose is pretty tightly clamped. I am going to take Peggie's advice and make a discharge outlet on top of the tank and plug the bottom hole.

The idea of an electric macerator has crossed my mind but it may be a bigger project than what I want to undertake at the moment.

Thanks.

[peghall]

A proper sullage tank has the outlet in the tank top connected to a pipe leading to the floor of the tank

That's the best way to do it, but the "standard" fittings locations that you'll find on all "off the shelf" tanks in the US have the fittings on one end of the tank...inlet and vent at the top, discharge fitting at the bottom. Only special order tanks will have the fittings anywhere else.

Tanks intended to drain via gravity, eliminating the need for an overboard discharge pump can also be special ordered. For this to work, the tank must be entirely above the waterline...the discharge fitting is IN the bottom of the tank typically--but not always--in the center of it.

--Peggie

[CaptTom]

I always learn something from these "head" threads! So I'll contribute some random thoughts I've learned through experience.

It's possible to modify a "normal" tank, with the discharge at the bottom, by threading in a PVC elbow, with PVC pipe up to the level of the top of the tank. Now you have your discharge at the bottom, but virtually no chance of having to remove hoses, valves or fittings below the level of the waste in the tank. Trust me, that's not a fun job.

Now, at the top of the tank, put in a PVC "T," But on it's side. Straight up is where you attach the pump-out hose. At 90 Degrees you attach the hose to the macerator. It can sit right on the top of the tank. Make sure it's a self-priming macerator - some aren't!

The toilet obviously goes directly to the tank in this arrangement. There's no Y Valve. You have the choice of pumping out, or discharging using the macerator where legal.

I've found this is the simplest set-up to install and, more importantly, to maintain.

No, you can't pump directly overboard from the head this way, so maybe those who spend most of their time offshore wouldn't like it.

Another problem is with boarding officers. Their 10-minute orientation on marine heads drilled them to search for the Y valve, and make sure it's locked. It might be wise to keep your old one, attach some hoses to it that lead off to nothing, and put a big ol' lock on it. Be sure to conspicuously label the locked out side "Overboard Discharge."

The "real" lock can be a key switch, which is 100% legal in US coastal waters. Another way some boat manufacturers address the lock-out rule is with two momentary-contact switches in an inconspicuous location near the helm, which must be toggled together to run the macerator. There's no chance of accidental discharge, and I'm sure it passed muster with the company's legal team. But I'm not so sure the boarding officer will agree, and I don't want to be the test case. Key switches are cheap.

Finally, my system doesn't allow for gravity discharge. That's OK with me. I can't help but think that solids could plug up the gravity feed openings and hoses, I'd drain out all the liquids and be left with a tank part-way full of solids. I wouldn't want to have to clear up that mess. I like the reassuring sound of a macerator grinding up everything it encounters!

[Disailor]

Anaerobic (oxygen-less or oxygen poor conditions) bacteria create hydrogen sulphide (stinky) gas. Aerobic bacteria, which creates carbon dioxide is available from RV suppliers. I add a small amount at the beginning of each season. If the tank vent is buried behind a bulkhead you will get stink released inside the boat.
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