Best holding tank pump?
Keith
that a diaphragm pump was better than a macerator pump. Opinions? Best
Brand/Type?
--
__________________
Keith
If you love something, let it go free. If it doesn't come back, hunt it
down and kill it.
Peggie Hall
> that a diaphragm pump was better than a macerator pump. Opinions? Best
> Brand/Type?
Unlike an impeller macerator pump, a diaphragm pump can run dry without
harm. Also has no moving parts. Best IMO is the SeaLand "T-Series" pump.
Peggie
Steve
around). That is about 50% more than a impeller pump but you get what you
pay for.
Steve
s/v Good Intentions
Peggie Hall
>
> The Sealand is what I use and I think they cost about $125 (if you shop
> around).
I think you meant $225...I've never seen one for less...Jabsco impeller
maceraters are about $125.
> That is about 50% more than a impeller pump but you get what you
> pay for.
Yep.
Peggie
> Steve
> s/v Good Intentions
Steve
is $317) for the Sealand model #301200. While the Jabsco Model #18590-0000
is $96.43 (list $214).
I realize not everyone will be able to get them wholesale (and as you can
see there is a hell of a markup), but if you shop around you could get
something priced in between.
My experience and opinion, FWIW.
Steve
s/v Good Intentions
Larry Weiss
for a macerator or diaphragm pump?
Larry Weiss
"...Ever After!"
"a little after..."
Peggie Hall
> for a macerator or diaphragm pump?
Nope.
Peggie
Garry W. Elmer
to a 1 inch overboard. It does a good job. If one really wants to get their
money's worth it can double as a washdown too.
http://www.99main.com/~elmergw/
Steven Shelikoff
>
> I don't know anything about the Sealand model but the Jabsco unit reduces down
> to a 1 inch overboard. It does a good job. If one really wants to get their
> money's worth it can double as a washdown too.
Oh man, I don't even want to think about doubling my head pump as a
washdown.
Steve
Garry W. Elmer
Doug Dotson
had a motor, diaphram, connecting rod and 4 duckbill valves that
all moved. The only problem I had with the diaphram pump was
that nasties (mostly TP) would clog in one of the 4 duckbill valves.
Not sure if this was related to the pump specifically but fixing
the occational clogup just got old after the first 3 times.
doug.
ps. Peggie can't hear me because she put me in her kill file.
She is mad at me for using the "B" word after she flamed me
in a private email.
Peggie Hall
require lubrication to prevent excess wear, and still require
replacement--things that don't happen in diaphragm pumps, but do in
impeller pumps and piston/cylinder head pumps.
Doug Dotson
create friction. I've replaced several diaphrams on diaphram
pumps because they do wear out do to fatigue. And the
bearings on the motor wear as well. I've also had to replace
the duckbill valves as well because they do wear out essentually
due to the rubber hardening over time.
Keith: It might be useful to define "better" a bit more clearly.
Each type of pump has it's advantages and disadvantages.
It all depends upon what your requirements are. Each pump
is good at moving poopy. One does it by chopping it up fine
enough that what comes out of your boat is not identifiable
and will dissipate quickly. The other (diaphram) can pump
solids as long as they are not too big but you can get stuff
floating about your boat that may disturb folks. The last
mascerator pump I opened up didn't have an impeller of
the traditional flexible type that will burn up if run dry. It
had a rigid impeller similar to those used in centrifugal pump.
No friction points other then the motor bearings, etc. Will not
self prime but does a good job chopping stuff up. In my
limited experience working with the innards of a mascerator
pump and more extensive experience working with diaphram
pumps, I think the diaphram pumps have more moving parts.
Mascerator has a motor connected directly to the mascerator
wheel (impeller ?). The diaphram pump has a motor, a gearbox,
a pushrod with articulated joints, several rubber valves, some
are belt driven, etc. I'd go with a mascerator pump if I were
doing what you are up to.
doug
ps. Thanks for not killfiling me, Peggy!
Doug Dotson
cleaverness of washing down the anchor chain and anchor
with human waste.
doug
Terry K
tank at sea, the best pump to use is a tire pump. You introduce
about 3 pounds of air pressure into the tank, and that pressure will
expel the tank contents if the piping connections are right.
This is the method I use to dump my holding tank at sea. The method
is tried, tested and true. The joker valve in the head is easily
able to withstand the back pressure required, and if it leaked back
a little bit, I would know it was time to renew it.
Terry K
no...@homesucks.com
wrote:
>If you are concerned primarily with the possibility of dumping a
>tank at sea, the best pump to use is a tire pump. You introduce
>about 3 pounds of air pressure into the tank, and that pressure will
>expel the tank contents if the piping connections are right.
>
>This is the method I use to dump my holding tank at sea. The method
>is tried, tested and true. The joker valve in the head is easily
>able to withstand the back pressure required, and if it leaked back
>a little bit, I would know it was time to renew it.
>
>Terry K
>
Worked great on the submarine....er, ah, unless some idiot forgot to
close a ball valve in the head or galley. Then we ate sandwiches,
those of us that weren't puking in our ballcaps....(c;
larry
Doug Dotson
stuff escape. Through a vent? Through the deck pumpout?
I have seen joker valves turn inside out.
doug
no...@homesucks.com
wrote:
>So when you pressurize your system, where exactly does the
>stuff escape. Through a vent? Through the deck pumpout?
>I have seen joker valves turn inside out.
>
>doug
>
ON the sub they blow it right out through a valve on the
bottom....with high pressure air, of course....
New subs don't do this because it makes noise. The Tridents have a
mascerator kind of pump and pump it overboard just like boaters do.
The pump, as with all the other pumps on the boat, is amazingly well
balanced, very powerful and very quiet. Most pumps, if you couldn't
see the shaft turning, you wouldn't know they were running, they're
THAT quiet.
larry
Doug Dotson
I was curious how is it done on Terry K's boat using a
tire pump?
doug
Terry K
little air. Contents jump ship.
That's it.
I have to lift the contents about 8 inches. If I had to lift it 5
feet, I'd need to use a different method, including a ball valve
between the head and the holding tank, as I would not like to make
my joker valve puke.
The discharge tube must be located in the bottom of the tank. The
contents exit through the standard marine toilet through hull sea
cock.
Terry K
Doug Dotson
bottom of the tank to the exit of the head. Do you need
another to switch the vent line from the vent to the pump
or do you just move hoses (yuk)?
doug
no...@homesucks.com
wrote:
>I see. An extra valve to connect the pumpout port at the
>bottom of the tank to the exit of the head. Do you need
>another to switch the vent line from the vent to the pump
>or do you just move hoses (yuk)?
>
>doug
>
Is it time for lunch, yet??....(c;
Terry K
through hull option for the head, a ball valve on the through hull
marine toilet discharge, normally closed. Open it, and pump air in
the vent line. Goodby ballast.
Over40pirate
Lauderdale, I bought a base unit, that the pump and bowl bolts to. I was
different than the orig on my head, in that it had a 1/1/2" plastic pipe plug
in the end opposite the pump. If un plugged, the bowl contents would drain out.
I installed a 1 1/2" ball valve in place of the plug. And ran a hose from the
bottom of my holding tank (which is higher than the head) to the ball valve. To
use the head, keep the ball valve closed. To pump the tank, open the valve and
pump away.
no...@homesucks.com
aren't LONG enough to make this an option....(c;
On 24 Oct 2001 00:32:59 GMT, over40...@aol.com (Over40pirate)
wrote:
Jere Lull
> If you are concerned primarily with the possibility of dumping a
> tank at sea, the best pump to use is a tire pump. You introduce
> about 3 pounds of air pressure into the tank, and that pressure will
> expel the tank contents if the piping connections are right.
>
> This is the method I use to dump my holding tank at sea. The method
> is tried, tested and true. The joker valve in the head is easily
> able to withstand the back pressure required, and if it leaked back
> a little bit, I would know it was time to renew it.
Sounds like you don't have any vents in that tank. How do you pump out, or
even use it? (air has to escape to let "stuff" in.) Or do you seal the vent
before pumping? Oh! Maybe a bladder.
I'd hate to see what happened if something plugged up....
--
Jere Lull
Xan-a-Deux -- '73 Tanzer 28 #4 -- out of Tolchester, MD
Xan's Pics & Specs: http://members.dca.net/jerelull/X-Main.html
Our BVI Vacation trip FAQ (250+ Annotated pics):
http://members.dca.net/jerelull/BVI.html
Steven Shelikoff
>
> Terry K wrote:
>
> > If you are concerned primarily with the possibility of dumping a
> > tank at sea, the best pump to use is a tire pump. You introduce
> > about 3 pounds of air pressure into the tank, and that pressure will
> > expel the tank contents if the piping connections are right.
> >
> > This is the method I use to dump my holding tank at sea. The method
> > is tried, tested and true. The joker valve in the head is easily
> > able to withstand the back pressure required, and if it leaked back
> > a little bit, I would know it was time to renew it.
>
> Sounds like you don't have any vents in that tank. How do you pump out, or
> even use it? (air has to escape to let "stuff" in.) Or do you seal the vent
> before pumping? Oh! Maybe a bladder.
He has a vent. That's where he's pumping the air into the tank, from
the vent.
Steve
Doug Dotson
into the bottom of the tank? Also, when you open the
ball valve, doesn't the tank fill with sea water? Or is
it above the water line (must be).
doug
Peggie Hall
Doug Dotson
Denis Marier
the piping design to use 3# of air to empty a plastic tank. a sea. At this
time, If I want to pump out at sea I have to pump the tank from the deck.
"Doug Dotson" <ddo...@digidata.com> wrote in message
news:3BD6C5DF...@digidata.com...
Doug Dotson
pump to empty the tank overboard. CG & DNR kind of
frown on it around here although I hear is is not technically
illegal until you use it. Mine is a more traditional setup with a
Y-valve to pump either into the tank or directly overboard.
Although being able to store-and-forward stuff can be useful.
doug
James Johnson
is 432 POUNDS over each and every square foot of tank. I think unless its a
very strong tank it will cause fatigue problems and cracking over time. FWIW,
while submarines use this method the sanitary tanks on submarines are designed
to take the same pressure as the hull, i.e. they are massively built.
James Johnson, ex sub sailor
Steven Shelikoff
>
> I wouldn't do it either. It puts a lot of stress on the tank, for example 3 psi
> is 432 POUNDS over each and every square foot of tank. I think unless its a
> very strong tank it will cause fatigue problems and cracking over time. FWIW,
> while submarines use this method the sanitary tanks on submarines are designed
> to take the same pressure as the hull, i.e. they are massively built.
I wonder how much suction the tank is under during a pumpout? It could
be close to 3 psi depending on the power of the pump and the flow of the
vent.
Steve
Terry K
a few inches above the waterline. The thru hull is only opened to
blow ballast.
Terry K
new and using 'new' water, I was able to blow the tank out with lung
power. -Don't look so squeamish! I will be installing a valve and
tee so I don't have to change pipe connections to connect the air
pump.
Open sea cock and pump in air through vent line. Good bye doo-doo.
Works good, really! With intelligent control of a second vent line,
the air pump could be used to periodically ventilate the tank
contents, and encourage low odour aerobic biological processing. An
Ultraviolet flourescent tube shining through a window could only
help, too. I suggested to Peggie once that such an air system could
be used to expell the tank (any tank!) contents forcefully enough to
soak a too close passerby on a PWC, but I think the charm of the
plan went over her head. I may install a 5 gallon water jug to serve
as a low pressure air reserve and forepeak bouyancy chamber.
I think 16 pounds pressure will lift water about 10 feet, but some
mathematician will dispute it in detail, undoubtedly. If your head
plumbing cannot currently handle at least that much pressure, it
probably leaks anyway. The joker valve can be expected to begin to
leak back at some point, but a ball valve shut off at the head could
handle that, if your lift height is so high that you fear for the
joker valve.
Terry K
Terry K
eh? What's a little doo-doo among friends?
The alternatives include a 1500 dollar macerator pump sitting mainly
unused, immersed, rotting in a cesspool. If you want to get a gold
plated pump with rindstones on the spokes, all you need is even more
money. I approach sailing the way I approach any problem. Off the
shelf solutions are best. less expensive solutions are best. I
expect that some think they need a space rated toilet. I do not.
I have spent the odd (very odd) afternoon standing on my head in a
puddle of shit in the bilge because some one else had a great idea
about how to make a 500 dollar polyethelene holding tank reliable
and durable. It wasn't that great, but I have seen and done worse.
I still have all my hair.
Technology evolves. Simplicity is more durable. I'll let you know
if and when my holding tank or plumbing explodes as a result of
unattended 100 pounds of air pressure inatentiveness. My system
needs about 5 pounds pressure to blow tanks. Common sense does rule,
really!
Terry K
Terry K
What did you do on the submarine? What kinds of sails did they
have? My Grandaddy was a submariner in WW1, a general duties oiler,
swabber and rear torpedoman, doubled as batteryman and dentist, I
believe. Old style diesel electric submariners did anything as
required anyway. The first qualification required was small size.
Can't ask him now, he's long gone. I never got to know him much when
I had a chance. Pity. He did tell me that the way they taught him
to swim was, they threw him overboard with a swimmer. People don't
need to learn how to swim. They have to learn how not to panic, how
to relax and how to endure.
The pressure is only on for 10 seconds or so while purging once a
week or so if there is no regular free pumpout handy. Surging half
full tank contents in a seaway will do more flex / fatigue damage,
IMHO.
I can see a way to set this thing up with a couple of air solenoids
and a push button so that I can purge tanks with no effort or
expense every time I turn towards home. My tanks would remain
empty, not full most of the time. Being so easily purged, the tank
could be a lot smaller, too.
C'mon, guys, a pepsi bottle can handle about 100 lbs pressure. 3
pounds pressure has the effect of stretching the walls of the tank
at a rate of 3 pounds per lineal inch of tank material. I should
hope that any tank material can handle a 3 pound strech per inch!
Heck, even gift wrap ribbon can handle that. The numbers you quote
are impressive manipulations, but bear no relevance to the
situation. A really huge tank at 3 pounds pressure could be said to
have thousands of pounds of tension spread out over a very wide
area. So what? It's irrelevant. 3 pounds tension in the walls. My
1/4" thick fiberglass tank flexes about, oh, a whisker, is all,
when being blown.
The way you calculate it, the logic says that the longer a hose
under pressure is, the stronger it must be if it is to resist
blowing the ends out of it. You brain is not seated right. In other
words, not to be unfriendly, your concern is poorly founded.
I do not fear for the safety of this plan. I expect to derive other
benefits, too. If the joker valve should get tired over time, I
would expect to see leakback into the head occurring at lower
pressure than required to purge the tank. If hoses are getting weak,
or connections degrading, I would expect small leaks under pressure
to indicate problems long before the whole thing just goes blooie!
If it got to be noticable, I would expect to replace the joker
before it failed, say about once every 3 or 5 years, by my
experience so far. That is less than the reccommended (by some)
interval of "ever year". Maybe it depends on diet, or commission
arrangements?
The ease of purging means that there is less temptation to use the
head in "marine" mode, keeping the sea cock open all the time to
prevent putting stuff into the holding tank. With this system the
sea cock is closed all the time, except to purge. Less chance of
syphoning and other leaky hose problems sinking the boat. Is your
head sea cock normally open or closed - honest injun, now?
I suspect that all objectors to this scheme are :
1. scared easily
2. unaware of certain basic physical facts, and/or
3. expensive equipment salespersons on commision ;-)
Alternatively, I remind you that "Best.. pump" is entirely
subjective. I already had a 12V tire pump. My "ballast blower"
system cost me nothing. Nada. 5 minutes of fiddling with a piece
of old garden hose and a clamp. What could be better than messing
around in a boat for free?
Is it better to have a 1500 dollar macerator pump rotting in a
cesspool, idle most of the time?
Not all submarine tanks need withstand the pressure of hundreds of
feet of immersion pressure. A stop cock would need be opened only
while tanks are blown, and sewage would need blowing only
occasionaly while near the surface, unless we talking nukes long
banished deep. My boat is sail powered, not nuclear, nor does it
regularly submerge, well, not very much.
If my system ever explodes, I'll provide full coverage, including
photos;-)
BZ, Dolphin man. We who stand on guard in the clouds are glad to
have fellows who guard us with different tools in the deep.
Terry K
Terry K
A reasonably free vent would allow full normal atmospheric pressure
into the tank to propel contents into an area evacuated by external
pressure relief without any stress on the tank. Sloshing contents (a
poopshake?) in a seaway would cause far more stress.
I say far more, because on a relative scale, the ratio would be very
high, just as the number one is infinitely larger than zero.
Terry K
Calif Bill
water. So figure a 1/2# per foot of head.
Bill
Terry K wrote in message <3BDC4352...@nbnet.nb.ca>...
Steve
to provide plenty of air in flow while your pumping. If you vent is blocked
off a diapham pump on board or at the pumpout station could collapse your
tank.
Regarding putting pressure on a tank, I would check out the tank design and
maybe even put a 2-3lb relief valve to prevent accidental tank damage.
My experience and opinion, FWIW.
Steve
s/v Good Intentions
Doug Dotson
doug
Doug Dotson
was original equipment. The other I installed and used a 1.5" vent.
doug
Steven Shelikoff
> Steven Shelikoff wrote:
>
> > James Johnson wrote:
> > >
> > > I wouldn't do it either. It puts a lot of stress on the tank, for example 3 psi
> > > is 432 POUNDS over each and every square foot of tank. I think unless its a
> > > very strong tank it will cause fatigue problems and cracking over time. FWIW,
> > > while submarines use this method the sanitary tanks on submarines are designed
> > > to take the same pressure as the hull, i.e. they are massively built.
> >
> > I wonder how much suction the tank is under during a pumpout? It could
> > be close to 3 psi depending on the power of the pump and the flow of the
> > vent.
>
It's always going to be under some suction during a pumpout. Even with
a 1.5" vent they'll be some vacuum, but not much. The smaller the vent,
the more vacuum.
Steve
Calif Bill
Bill
Steven Shelikoff wrote in message <3BDE0279...@yahoo.com>...
Terry K
>
> Would not the toilet itself provide a vent during the pumpout.
> Bill
You too seem to have heard the wild waters' call during pumpout
season, eh?
SHLOORP! is the sound of a marine toilet sucking air to allow the
tank to empty.
SHLOORP! is the sound that means the vent is plugged.
If the vent is not plugged, there will be very little vacuum
resisting pumpout until the tank and suction lines empty. Then, the
vent will have to provide all the airflow that will be induced by
the pumpout machine, once the hoses are all sucked empty. So, after
the tank and lines ashore empty, the airflow will increase, which
will increase the pressure drop in the vent lines, much like a short
circuit in electronics causes other connections along the current
path to contribute a larger proportion of the series voltage drop.
That is when the marine toilet mating call "SHLOORP!" will be
heard.
Ah, romance, ain't it grand?
Terry K
Calif Bill
in a 26' Motorhome. My boats do not have pottys. May get one in a couple
of years.
Bill
Terry K wrote in message <3BDEA9C4...@nbnet.nb.ca>...
James Johnson
Tech and Engine Room Supervisor (MM1/SS/LELT), we operated the mechanical
systems for the reactor and engine room, the evaporators (to make water), the
emergency diesel generator, A/C systems, and the main air compressors.
The fact that a pepsi bottle can handle 100 psi is not applicable to a large
tank. The tensile stress is proportional to the circumference. A cylinder 1/2"
in diameter will have walls 1/10" thick to handle 2000 psi, make it 3" in
diameter and the wall thickness will have to be .5 to .75 inches thick to handle
the stress.
Plastic holding tanks are far better able to take the tensile stress of
pressurization than the compressive force when you draw a vacuum (which will not
happen if the vent is not clogged). A quality tank will take it, however you
might have fatigue cracking in 10 or 15 years, aggravated by the impact forces
of sloshing tamk contents. The flexibility of the tank will dissipate some of
the impact force, an affect which doesn't occur when the tank is pressurized
(pressurization is more continuous). Unless your tank is very small, 4 or 5
gallons, 10 seconds is not enough to empty it through an inch and a half hose
with 3 psi of air pressure.
A long time ago in a squadron far, far away, on a submarine tied alongside a
tender (very large repair ship) in an anchorage, an auxiliary operator found out
to his remorse that if you pressurize a sanitary tank to 100 psi, and open the
surface discharge valve by mistake instead of the bottom discharge, raw sewage
will spray a hundred feet in the air to saturate the Commodores stateroom
through his open hatch and porthole. And yes, the Commodore was in his
stateroom at the time.
JJ
James Johnson
holding tank over the side. My system can be set up for the head to go to the
holding tank, head to go over the side, pump the holding tank manually ( 1 1/2
to 2 minutes tops), or having it pumped out from a shore side pump out station.
It is a very simple, inexpensive, reliable system - one manual diaphram pump,
two three-way valves, one y-connection. Since I sail on the Chesapeake and
rarely get to go offshore, the holding tank to shore pumpout is the way it is
usually setup.
JJ
On Sun, 28 Oct 2001 17:52:12 GMT, Terry K <tksp...@nbnet.nb.ca> wrote: