Head High Loop & diverter valve

Maineiac · **Posted:** 27 Dec 2022 13:55

My boat had no high loop from the head outflow. Just a diverter valve under the sink to the holding tank or out. I replaced all thru hulls and the valves and plumbing lines. So if you make the boat "legal" w/in 3 miles of shore by "locking" the diverter valve to the holding tank with zip ties, there's a problem. Diving up and down big seas in the Gulf of Maine (and down here), anything in the holding tank flows back into the head. Stinky. With a nice nutmeg smell from aged shit. Didn't know. I'll risk the fine for now, but . . .

Has anyone installed a proper vented high loop for the head discharge? Will it fit behind the cabinetry against the hull? Wife re-installed all the cabinetry after I checked out the chainplates and ran some wiring and did a stellar job. She knows how to take it apart again. She thinks it might fit. Maybe behind the little cabinet next to the sink?

WayneH · **Posted:** 27 Dec 2022 17:49

I've had those cabinets out 3 or 4 times but I never measured the cabinet depth versus the hull depth. But in my opinion, there is not 1-1/2" clearance behind the cabinets.

You're welcome, leave your payment with the nice lady out front. Snicker

Maineiac · **Posted:** 28 Dec 2022 07:34

Do you have a vented high loop? The marelon valve I've got is only 2 way. Maybe a 3 way valve with one position "off"? I've never been checked but there's always a first time.

WayneH · **Posted:** 28 Dec 2022 15:11

No, my setup is straight to the top of the holding tank. I did that revision after I got stuck in the Louisiana ICW with a full tank and no access to pumpout. What I messed up with was not putting any loop between the head and the tank so sometimes I get back flow. Yuck. It's on my list to correct by getting as high as possible under the sink.

The pumpout comes out the top also with a dip tube to mostly clear the tank. Between the deck fitting and the tank, I installed a pipe "T" pointing up. That line goes up to a manual macerator pump and a vented loop before going to the overboard discharge valve. The discharge is always closed so the dockside pumpout only pulls on the tank.

Maineiac · **Posted:** 28 Dec 2022 16:21

Maybe the hanging locker . . . maybe behind the sink. Need to get high enough so no backflow. And thinking about it, I don't believe it has to be vented. Just the tank itself needs venting.

puffcard · **Posted:** 28 Dec 2022 18:24

We have a vertical loop with vent in the cabinet behind the head. Looks original to me. Make certain you have good flexible hose to to be able to route it. We go from head up vented loop, to y-valve locked to holding tank. Holding tanks discharge thru maceration pump, suction on tank top. Goes thru isolation valve to T before hull valve.

berwick · **Joined:** 21 Oct 2006 18:12 **Posts:** 327

I don't think anything should drain back if your joker valve is in good shape? When I start getting anything back I change the joker valve and all is good,

Richard

Velera · **Joined:** 29 Dec 2006 09:38 **Posts:** 656

you should not need a vented loop in the factory installation. The head rim is above the waterline (just). It would be a safety measure, perhaps. I think most production boats do this to avoid a lot of tubing and vents. Yes, the tank needs a vent.

Maineiac · **Posted:** 21 Jan 2023 14:40

I'll try the joker valve first. The marelon diverter valve is stiff as a bastard. The head outflow goes into the top of the side of the tank so when we're pounding fluid splashes into the line and runs downhill back to the head. Joker valves perform with back pressure, so just some splashing might not provide enough pressure on an older valve. The tank is vented. I have a new vent to install just because. Because if that little stainless screen rots away, mud daubers load the line. Same thing with the fuel tank vent.

Tartan37.com

Head High Loop & diverter valve

Who is online