Electroscan revised plumbing

[Syversens]

Hey all,

So a few weeks ago we had an incident with our Raritan Elegance and Electroscan unit, which has been operating flawlessly for 5 years I might add. We started experiencing backflow thru electroscan and toilet into bowl but was discovered before disaster occurred. We immediately started practicing thru hull closure when underway and that worked. I then started investigating our setup and found that my vented loops were not adequate so I modified my plumbing to the following (from intake to discharge)

Hose from intake to pump (with shutoff of course)
Vented loop between pump and bowl (this was already present and I thought sufficient)
Replaced joker valves (2) on the elegance
Added vented loop on discharge between bowl and electroscan (this was not existing before and probably reason for the back flow)
Plumbing from electroscan out as before, electroscan is above waterline at any heal.

So.... My sloppy initial install cost me 3 hours of replumbing but have I accomplished what I needed with this setup? Of course I believe I have but curious what the pros say.

Also I noticed that now when I run bucket of fresh water thru the electrscan (something we do religiously before storing for more than a week) there is a easily audible whistle from the new vent after flush, I'm assuming that is when siphon break happens and the intake is small and now there is far more air... Is this normal? I've tried turning the duckbill valve but sounds the same.

Cheers!

 

[Allan12210]

Did you already have a vented loop between the ElectroScan discharge and the through hull? This isolates the ElectroScan unit from the outside (back flow) especially in the case where it is below the water level or while underway when hydraulic pressure can occur. Good move to shut the big valve when not actually using it.

 

[Syversens]

No I did not have that vented loop but installed one now. I know I should have but I thought the intake loop was enough, it's definitely not. Also the awesome joker valves did their job for 5 years, I really like the Raritan products.

This was all my fault so I am curious whether I've covered my loops and if there is anything that can be done with the vent whistle. I've ordered a hose barb vent fitting to go to where my old holding tank vented, that way the discharge vent can hopefully push any smell outside.

 

[Peggie Hall HeadMistress]

What do you mean by "hose barb vent?" Hopefully not the typical "vent" thru-hull...those are designed for fuel tank vents, boat builders use them on all vents because it costs them less to buy one type in bulk than using different thru-hulls for each purpose. They're totally wrong for waste tanks because they don't allow the air exchange needed to keep the tank aerobic, which is necessary to prevent odor.

 

[Syversens]

Hey Peggie, no it's not, its part number 903004 on this page. All it does is vent the valve from the duck bill out so air is sucked from the outside and if odor was to leak thru duckbill it would go out that hose. the vent out is above heel and located very close to the vented loop.

 

[Peggie Hall HeadMistress]

Aha...a vented loop air valve.

I'm gonna bookmark that page, 'cuz those aren't always easy to find...whichi is why so many people make the mistake of putting a vent LINE on a vented loop as a solution to squirting.

 

[Syversens]

You recommended our Raritan Elegance and electroscan and the pair has performed beautifully for years, no pump out and happy mrs, both make boating life easier.

I'm not sure I'll actually install it, like you say it's not common but I figured I'd get it as the idea is good. The thought of having an open duck bill valve into a black water line wasn't very appealing so I'm investing $8 as a backup.

Thanks for all your help and sounds like I'm one step closer with my setup.

 

[Peggie Hall HeadMistress]

Install it...the air valve is what makes 'em work...closes when liquid is pulled through a line, opens when pulling ceases to provide an air break that stops the flow. Air valves prevent squirting through the hole in the top of the loop in a line through which water is being pushed.

Air valves are very common, at least among knowledgable boat owners...and belong in vented loops in ANY line. Because they're replaceable parts, they're often sold separately from PVC loops...the kids who work at marine stores these days don't know they exist, so the average "weekend warrior" is left to come up with his own solution to squirting, and that's almost always a vent LINE...bad idea, 'cuz that line is only 1/4" ID, so small that that it very quickly becomes clogged up with salt and sea water minerals...turning the loop into an UNvented loop that can no longer create an air break...and since it's solved the problem--squirting--it's become "out of sight, out of mind" and never cleaned out