Basil P wrote:
Peggy,
I have a RONCO tank that I installed in 2002. I has worked very well.
Except for the pump out suction. I had the tank built with the input
on the top along with the vent. The discharge fitting is installed at
the bottom of the tank.
I have had some trouble getting it completely pumped out. I have read
that you have recommended having the pump out fitting from the top via
a dip tube. I think that I can accomplish this change. I have one
question though.
How close to the bottom should the tube be to get the most complete
pup out? Also is the tube straight down or is there any holes in the
side of it near the bottom?
It won't solve your problem. A fitting at the bottom will leave about an
inch because the pumpout loses prime and starts sucking air when the
level drops to the top of the of the fitting... a "dip tube" that goes
all the way to the bottom has to have at least a 25 degree angled cut in
it to prevent any undissolved paper or solids from being caught under it
and clogging it...so you're still left with about the same 1/2"-1" in
the tank. Don't put any holes in it...if you do that, you won't be able
to pump out past the first hole...'cuz that's the pumpout will lose
prime and start to suck air.
Someone is likely to suggest installing a P-trap in the pumpout line
coming out of the tank at the bottom. Bad idea. The only point of
putting all fittings on the top of the tank is to eliminate standing
waste in the pumpout hose to permeate it...putting a trap in the fitting
doesn't solve that problem, but instead only raises the level in the hose.
That an inch is left in the tank is not a bad thing...'cuz you should at
least nominally rinse out the tank after every pumpout by adding a
couple of gallons of water down the deck pumpout fitting to stir up and
pumpout any sludge. But few people do that (and then complain about
sludge build up in their tanks). If the tank totally emptied each time
you pumped it out or dumped it, sludge would only build up faster 'cuz
it wouldn't have anything to dissolve in.
You won't accomplish what you want to by moving the pumpout fitting to
the top of the tank...so IMO, you're just as well off leaving it as is.
Btw, I'm prob'ly gonna be MIA from here for the next week...leaving on a
7:30 am flight in the morning for the Annapolis Sailboat show. Fawcett's
Boat Supply carries a lot of my publisher's books and has given my
publisher some space in one of their booths for "vendor support"...and
in a prime location, too--in the big A tent, across the aisle from
Raritan (just a coincidence, btw). So if any of y'all are planning to
come the show, I hope you'll stop by the booth and say hi. I also
promised to spend some time doing vendor support for my book in
Defender's booth, but not sure when...so if I'm not in the Fawcett
booth, look for me there. I'll only be there for the sail show,
btw...for the whole duration, though.
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://shop.sailboatowners.com/detai...=400&group=327
http://www.seaworthy.com/html/get_ri...oat_odors.html