Vented loop

[Windblown]

I just installed a whole new system (Raritan PH II, hoses, vented loops, holding tank, and seacocks) in my boat, but can't seem to get it to pump much water into the bowl when I flush it. I used Marelon vented loops on both the discharge and intake side, 1.5 inch and 3/4 inch respectively, to prevent siphoning. If I disconnect the intake one, and go straight from the seacock to the head inlet, it seems to work fine. Is there something I am doing wrong? Maybe I have a bad vented loop? If I plug it with my finger it it works better, but otherwise it draws in too much air to allow effective pumping.

Thoughts?

 

[Ron20324]

The vented loop goes between the pump and the bowl, not between the seacock and pump.

 

[Chuckbear]

Here is a very good discussion on head installations, http://www.boatus.com/boattech/casey/13.htm and you might want to be sure you even need a vent on the intake. Chuck

 

[Peggie Hall HeadMistress]

What do people have against reading the directions...<sigh>...

'Cuz if you'd read the installation instructions for your toilet before you installed anything, you'd have seen where the intake vented loop belongs and wouldn't have put it in the wrong place. 'Cuz that's what your problem is.

You've prob'ly already thrown 'em out without ever even taking 'em out the plastic bag--so there went the maintenance instructions too...but all isn't lost...you can download and print out another copy from the Raritan site: http://www.raritaneng.com/pdf_files/ph_II/L04v0505.pdf 2n paragraph under "Plumbing" on page 5 says in bold print: "Intake vented loops must be installed between pump and back of bowl." Figure 1A BELOW WATERLINE INSTALLATION" on the same page provides an illustration of correct plumbing.

I'm betting your next question will be "what can I do to stop water from squirting out the hole in the top of the DISCHARGE vented loop...so I'll save you the trouble and answer it now: If that's happening it's because the air valve--one way valve that only lets air INTO the line to break a siphon, nothing out--is missing...they're often sold separately because they're a replaceable item that needs periodic cleaning and occasional replacement. Do NOT put a "vent line" on it instead! The line would have to be so small--only 1/4"--that it will very quickly become clogged by sea water minerals and salt, turning it into an UNvented loop that no longer has any ability to break a siphon.

 

[Ross]

Re: What do people have against reading the directions...<sigh>...

Peggie, Men don't read instructions for the same reason they won't ask directions, it is non macho.

 

[Windblown]

Re: What do people have against reading the directions...<sigh>...

Peggie
Ok, I see my mistake. Besides not reading the directions closely enough. Fortunately my wife wasn't around to confirm that i am an idiot, or learn any new words.

Thanks!
Kevin

 

[Peggie Hall HeadMistress]

Wives do come in handy for that

Btw...make sure that both your vented loops are high enough to be at least 6-8" above waterline AT ANY ANGLE OF HEEL...which, on most sailboats, puts 'em about 3 FEET above the toilet.

 

[Windblown]

Re: Wives do come in handy for that

That much I did do correctly. They are just under the deck, as high as I can get them, and at least 3 feet above the toilet. As long as I keep the port rail above water, it should be fine. I corrected the intake hose routing, and it now works like a champ.

And btw, I did check both vented loops before I installed them, to be sure they had the duck bill valves in them, and that they were oriented correctly, allowing air in, but keeping water from squirting out. I also intend to run a vent hose from the discharge one to my overboard vent, to keep the smell out of the boat, as you suggest.

Thanks for your help
Kevin

 

[Ron20324]

Am I reading that you have a vent in the line from the head to the tank? A no-no, in that it could/would get easliy clogged.

 

[Peggie Hall HeadMistress]

Don' do dat, Kevin...and Ron...

"I also intend to run a vent hose from the discharge one to my overboard vent, to keep the smell out of the boat, as you suggest."

You got it backwards...If you scroll back up to my first reply, you'll see that I specifically warn AGAINST putting a vent line on a vented loop.

"Do NOT put a "vent line" on it instead! The line would have to be so small--only 1/4"--that it will very quickly become clogged by sea water minerals and salt, turning it into an UNvented loop that no longer has any ability to break a siphon."

If it isn't squirting water, it isn't "squirting" odor either...so leave it alone except to clean the air valve every couple of months.

Otoh--and this should answer Ron's question...since there's no way for a siphon to occur in a head discharge line that only goes straight to the tank, there's no need for a VENTED loop in that line anyway--although a loop high enough to prevent backflow when the boat is heeled can be needed if the inlet fitting on the tank is in the wrong place. So a vented loop isn't a no-no, it's just overkill... no more likely to become clogged than a vented loop in a head discharge line going overboard, where one IS required. Ron, I think you're confusing "vent line on a vented loop" with a vented loop itself.

 

[Windblown]

Re: Don' do dat, Kevin...and Ron...

Peggie
Ok, got it. I have the discharge set up to go first to a y valve, then either to a vented loop and to the overboard discharge seacock (hence the need for a loop) for use while at sea, outside of the legal 3 mile limit of course, or to the holding tank, bypassing the vented loop. I know I read somewhere suggesting putting a vent hose from the loop overboard, to prevent any air from the line from entering the boat, but I can certainly leave that off. It would have been a half inch line, in any case.

Thanks again
Kevin