1" Y Valve for sewage - opinion/experience

Hello and Thanks for Reading
My electric toilet has a 1" discharge out of the built in macerator, looking for a Y valve to direct the output between overboard discharge and holding tank.

When I had a manual head with 1 1/2" line the valve leaked within a year of install. So I am overthinking this purchase.

I can find 2 makers of 1" Y valves, Forespar MF-Series or Bosworth. I like the Bosworth as it's available in flush mount, but don't like that it has smooth connections .vs. barbs. If they didn't use some crazy thread on the fitting this is fixable.

Any experience with either of these brands? The previous valve was a Whale. Forespar is a familiar name to me, Bosworth is not.

went with forespar 1 1/2 Y's in case I ever change out systems.

used reducers from Y's to the 1 inch lines at a fraction of the cost of a later change...

plus figured the larger Y's might be less prone to clogs and larger parts seem to have less failure issues.

what brand failed so we don't make the same mistake?

When I had a manual head with 1 1/2" line the valve leaked within a year of install.

That had nothing to do with the size of the tailpieces. If it leaked at a hose connection, the tailpiece may have been out of spec, or it may not have been double clamped. If the valve itself leaked, that was indicative of the quality of the valve.

Forespar and Bosworth are comparable quality--both good ones. Smooth tailpieces seal hoses just as well as ribbed ones...all Dometic/SeaLand fittings are smooth. It's only important that the hose be a good tight fit on it and double clamped with screws 180 degrees apart...at least 90 degrees if accessibility makes 180 impossibly difficult. Reason: a hose clamp can cause a slight pucker in the hose under the screw, which can cause the connection to leak. The second clamp may also pucker the hose slightly, but because its screw is well away from the first one, it prevents any leak.

It would make much more sense to discharge the electric head directly into the holding tank and then have the Y on the tank discharge line? In today's production boats, the head is plumbed straight into the holding tank. Builders know that you are not permitted to discharge within the continental waters of the US. From the tank you can go to a deck pump out or to a macerator and out to the sea. The Y can only be used 3 miles off shore (9 miles of the west coast of FL) And how often are you going to use the head out at sea? Probably not very often. 99.999% 0f the time you use your head you are inside the continental waters of the US and you cannot dump directly overboard. Rather than have an unused Y between the head and the tank, make that a straight run to the tank with no intermediate fittings to leak . So it looks like you may live in Ohio? While you are in the inland lakes and rivers aren't you required to have the hose physically disconnected from the seacock?

I agree with tadhana, but I would eliminate the Y valve altogether. Instead use a Y or T out of the holding tank.

This diagram is from Ronco plastics. They make holding tanks. I'm planning to use this method for my boat.

ohhhhhh, some will say only top of tank penetrations....

but like many boat systems...they are what they are...and only 100th of a problem TFers will invent .

The valve was a whale, and the valve leaked not the fittings.

The Y valve is for emergency use only. If the tank is full, and the Admiral's gotta pee, she's not going over the side.

For head plumbing only double clamped AWAB clamps will do, nothing less.

I don't have a lot of room in that space which is why I'm not wanting to go with the 1 1/2 to reducer route it makes a big valve.

Thanks for the advice on the two products being equal. I'm going with the flush mount Bosworth. And don't worry the sea cock will be locked to satisfy the pee police. Who would have a field day in my Marina but that's another story...

Like Peggie said, the smooth connections are fine.

I’m with tadhana, I like to plumb the toilet directly to the tank and never discharge directly overboard. If I was crossing oceans, I might use a y-valve to discharge directly overboard, but not for coastal cruising.

On the tank discharge I would use a simple tee. The cap on the pump out fitting would allow the macerator pump to generate suction and when using the dockside pump out, the macerator and seacock allow the dockpump to generate suction. This set up worked fine on my boat for many years.

I never got around to doing this but Peggie taught me a trick that would allow you to legally leave your discharge seacock open. She suggested installing a key switch to control your discharge pump. Don’t leave the key in the switch so that it isn’t too easy to discharge sewage and your good to go. Good to go, snicker.

You do have Peggie’s book don’t you?

FOG said:

I agree with tadhana, but I would eliminate the Y valve altogether. Instead use a Y or T out of the holding tank.

This diagram is from Ronco plastics. They make holding tanks. I'm planning to use this method for my boat.

Click to expand...

My setup is like this, with all hoses out of the top of the holding tank. No Y valve, everything goes in the tank, after which it can be pumped out at the dock or pumped overboard with a macerator pump if in area legal to do so.

Ok, I admit it, I’m cheap. I see no reason to add a 179$ pump for the possibility that I can’t pump the tank and the Admiral has to pee... Plus a pump rarely used is a pump that has a short life.

And yes, Peggy is awesome.

Ronco makes outstanding tanks, but there's a lot wrong with their plumbing ideas (it wasn't that long ago that they were still selling corrugated sanitation hose).

The filter in the vent line is the first thing. There have been enough discussions about vent filters here that I shouldn't need to say more.

And WHY is the vent line connected to a tank level indicator??? They have nothing in common!

The second thing is the vent line coming off the top of the vented loop. There should be an air valve in the top of that loop instead. A vent line is a bad idea because it has to be so small (1/4") that it quickly becomes clogged by waste and sea water minerals, turning it into an UNvented loop that no longer has any ability to prevent a siphon. And because it's solved the squirting problem, it also quickly becomes "out of sight, out of mind," so is never cleaned.

Although the following aren't real errors in their illustration, I'm a big advocate of two things: 1. all fittings on the top of the tank, with pickup tubes inside the tank. This eliminates standing waste in any line and also makes it unnecessary to plumb a "trap" in the discharge line...which isn't that great an idea anyway because although it does allow the last inch in the tank to be discharged, it leaves no liquid in the bottom to prevent sludge from turning into concrete. 2.TWO discharge fittings in the tank eliminate the need for either a tee (which I don't like because it doesn't provide any way to shut off flow from the tank when it becomes necessary to repair the pump--which NEVER happens when the tank is empty!) or a y-valve (which does).

And as long as I have the floor...I don't know how many of you are members of the MTOA, but they've invited me to give a couple of seminars at their rendezvous in Ft Pierce in April... you can read all about that here:
SR 2018 - Marine Trawler Owners Association

If you're members, I hope you'll come, 'cuz I'd love to be able to put faces with some of the names here.

Peggie
"If you can't explain it to a six year old, you don't completely understand it yourself." --Albert Einstein

This is the Y valve I used when I replaced heads, and plumbing 2+ years ago. I live aboard 9 months of the year and it has worked fine, I did plumb with 1” hose.

There are several ways to deal with poop on a boat and I don't think the diagram posted above is necessarily the best one. On my boat, poop goes directly into the holding tank. There are no options.

Removing poop from the holding tank can be done by sucking it out the deck fitting or pumping it overboard. There are no Y valves and no seacock on the discharge, it's above the waterline. There are two outlets at the bottom of the tank, one for the deck fitting and one for the macerator. Yes, internal dip tubes would have been better but the hoses haven't been a problem.

For compliance reasons, I replaced the original push button switch (for the macerator) with a key switch and I don't leave the key in the switch.

When we're in a marina we use the marina facilities when practical.