"Dave" wrote in message
...
On Mon, 12 Dec 2005 15:24:19 -0500, "Skip Gundlach" skipgundlach at gmail
dotcom said:

So, if I understand vented loops properly, suction gets air, rather than
water, thus preventing siphoning. So, how do you suck in the supply water
if the supply line is vented???

Peggy has already explained that the vented loop goes between the pump and

"Already," after I'd posted my question...

the head bowl, not between the pump and the intake. On the upstroke, the
pump applies suction to draw water in through the intake, and that suction
isn't broken since there's no vent in the line it's pulling on. On the
downstroke the pump is applying pressure to push the water from the pump
to
the head bowl. That pressure closes the vent valve, since it's from inside
the line, not outside the line.

and


"Peggie Hall" wrote in message
om...
Skip, have you ever bothered to the read the manual for your toilet? It
includes drawings showing the locations for both discharge and intake
vented loops.

No, Peggie, to your question, having not had a manual (or at least, that
we've discovered, yet, having moved the entire interior contents of the boat
not less than 3 times in the course of our refit) for our Raritan PHIIs, I
didn't see anything to that effect. Or the question would not have arisen.
Despite my quest for clarity and understanding on things I've not dealt with
many times already, I do have a mechanical bent and a better than ordinary
spatial perception. Given my situation (see below), which I assumed to not
be atypical, I couldn't readily make the leap to "outflow" rather than
"inflow" in the supply line chain. On my boat, the outflow hose(s) is/are
about 6" long, going directly from the pump to the intake on the bowl, which
I assumed to be standard.

Earlier (way earlier, maybe a year, in a thread about LectraSans) I
commented about the extraordinarily long runs in the aft head. The removal
of the LS makes the exhaust run only about 15 feet, total (counting the 3'
up and down it has to go to the vented loop top). However, I infer from
what I see in the thread, now, that I'm looking at something similar for our
intake.

Our intake is on the other side of the keel from the exhaust, both of which
are in front of the head (well, technically, aft of the head, but in front
of how you'd sit, rear [pardon the expression] facing, on the stool). The
only cosmetically acceptable location for a vented loop is in the engine
room, about 4' or more from the thru hull, not counting the up-and-down to
get to the pump from under the sole and raised stool location. It would
also mean another hole in the stool deck (one to go from the pump, out and
under to the engine room, and the other, original, to go back in, to go to
the toilet supply).

From all the preceding vented loop discussion, as much rube goldberg as that
seems, it's what's needed? Or, every time the head's used, the t/h valve
gets closed? There *is* a handle'd valve on both terlets' intake hoses.
Perhaps that's what it's about? Aside from the nuisance value of that, does
that suffice?

Thanks. I'm not really dense - I just want to make sure I don't screw up,
and I've not dealt with marine sanitation all my adult life...

L8R

Skip, still ashore, but getting closer to stepping aboard and cutting the
cord as PT progresses apace


--
Morgan 461 #2
SV Flying Pig KI4MPC
http://tinyurl.com/384p2 The vessel as Tehamana, as we bought her

The Society for the Preservation of Tithesis commends your ebriated
and scrutible use of delible and defatigable, which are gainly, sipid
and couth. We are gruntled and consolate that you have the ertia and
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