Holding Tanks

>>>In the US (and most other waters) there is no prohibition against using the lee rail or "taking a swim"...only against putting waste into or passing it through any device aboard first (I never said it made sense, only that's how it is). So the lee rail is legal..."bucket and chuck it" is not. In a harbor or anchorage, one is expected to have some consideration for other when it comes the aesthetics of "direct discharge."<<<

Peggy

Thanks for the reply, and as they say don't shoot the messenger! However this has great importance when sizing the holding tank or at least on the length of time between pumpouts or visits offshore. We routinely follow the pee on it's own OK poop and paper not OK rule which means we have loads of capacity with a 20 gallon holding tank. I suppose we could use a pee bucket below and pour it down the washbasin as 'grey' water, bit of soap added maybe.../forums/images/icons/smile.gif

Robin


<hr width=100% size=1><font size=1>Sermons from my pulpit are with tongue firmly in cheek and come with no warranty!</font size=1>
 
Peggie. Thanks again. Most helpful. I've asked for a quote on a bespoke hard tank from Tek Tanks and will go from there. I'm a bit daunted by the size of the recommended vent - 38mm sorry inch and a half and where to site it.

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Tillergirl...Before you place an order, let's get together via PM or (preferably) email to discuss the best place to put it and how best to plumb it. You may not need quite that large a vent.

Robin, I only shoot messengers who shoot at me first. :)

<hr width=100% size=1>Peggie Hall
Specializing in marine sanitation since 1987
 
Sorry Peggie...

.....I meant you were the messenger and shouldn't be shot. /forums/images/icons/smile.gif

<hr width=100% size=1><font size=1>Sermons from my pulpit are with tongue firmly in cheek and come with no warranty!</font size=1>
 
Peggie, thank you, will do.

Personally I found at work it was always best to shoot the messenger, preferably before they delivered the message.

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Doesn't work...they just keep sending more messengers.

<hr width=100% size=1>Peggie Hall
Specializing in marine sanitation since 1987
 
Pipe size problems

From reading about loos it seems as if its possible to use smaller pipe sizes if you have a macerating electric toielt. It certainly works on full sized toilets at home. This might ease the installation of a holding tank. Its an expensive way of solving the problem though and obviously brings others in its path. I would lik the Headmistresses opinion on the matter.
Dear me what a load of unintentional puns.

<hr width=100% size=1>Roger
 
I installed a holding tank, which I had made in Germany from high-density polyethylane, wall-thickness of 5 or 6 mm. I supplied the maker with a drawing of the dimensions so the tank would fit as good as possible in the available space. To fill and empty the tank I used the pump of the Lavac-toilet. Just before the pump I installed a two-way valve connecting the pump either to the toilet or the tank. On the outlet side of the pump another two-way valve was installed to pump the substance in the toilet either to the holding tank or directly overboard. By switching the valves it was possible to empty the tank overboard (which we did while in open sea), pump the contents of the toilet directly overboard, pump the contents of the toilet to the tank and to pump things around, without pumping anything overboard. This could be useful to clean the tubes connecting toilet, tank, pump and valves. This system worked perfectly for quite a number of years. Any problem was more in the components, such as a leaky pump, but not in the actual system.

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Re: Pipe size problems

Roger, I can easily see how reducing the size of your household toilet piping--which is about twice the diameter of ours--would result in more efficient flushing...but since it appears from the drawing on the Tek-Tanks site that the standard size for marine systems is the same as in the U.S.--1.5" ID for all toilets, macerating or not--I don't think you'd gain anything. Only one US mfr--Jabsco--uses a 1" discharge on all their toilets--manual as well as electric...but even they now offer a 1.5" alternative discharge fitting. Going smaller can actually cause more problems in some installations than it solves, especially if the toilet is one that uses a large volume of flush water and/or the piping has a lot of bends in it...'cuz only so much volume can go through without backing up. There's also the matter of sea water mineral buildup in hoses...unless scrupulously kept clean, it reduces the diameter of any size hose--the warmer the water the faster they accumulate. Starting with a smaller diameter hose can lead to a complete blockage much faster.

And I'm not sure how going much smaller than that would make it easier to install a tank...any tight bends in the piping would cause a smaller diameter hose to collapse much more easily than larger diameter hose.

In short, there's good reason why the standard is 1.5" for both manual and macerating toilets...it's proven to be smallest diameter that doesn't create more problems than it solves.

<hr width=100% size=1>Peggie Hall
Specializing in marine sanitation since 1987
 
Re: Pipe size problems

Peggie - I bow to your superior knowledge. I was impressed by the small size of output tube from a macerator equipped domestic toilet that I saw in Sweden. There was of course no problem there with salt water causing chalking up.
In general I would expect the bend radius of flexible pipe to be proportional the pipe diameter thus easing installation. However as you point out, other factors are more important.
Again, in a domestic context, I am happy to have a 6 inch soil pipe at home rather than the more usula 4 inch.

<hr width=100% size=1>Roger
 
Re: Pipe size problems

Our domestic toilets have only a 2" discharge--which a friend visiting from the UK happened to notice as we passed by the plumbing dept at Home Depot and found it so intriguing that when I finally found him again he'd all but taken one of the floor models apart to see how it worked. Our domestic (in the house) sewer pipes--into which the 2" toilet discharge lines tee--otoh, are 4".

How susceptible a hose would be to collapsing in a tight turn really depends on the wall thickness of the hose as much as it does on the diameter...thinner softer hose will collapse far more easily than thick stiff hose. If it were possible to post a photo here, I could show you a perfect example of what happens when even some 1.5" hose is bent tighter than it should have been.

<hr width=100% size=1>Peggie Hall
Specializing in marine sanitation since 1987
 
Re: Pipe size problems

Peggie, if you want to show a photo here, send me a pm with your email address, and I'll send you my email address. You can send me photo, and I'll post it here.

<hr width=100% size=1>Me transmitte sursum, caledoni
 
Re: Pipe size problems

Here it is

10457044-M.jpg


<hr width=100% size=1>Me transmitte sursum, caledoni
 
Re: Pipe size problems

Thanks Brendan.

Ok, class...what caused this, and what should the installer (who could have been the owner, a yard, or even the builder believe it or not) have done to prevent it?



<hr width=100% size=1>Peggie Hall
Specializing in marine sanitation since 1987
 
Re: Pipe size problems

A hard bend, like you get on a washing machine, would prevent it. But how to get one to fit that pipe is another matter!

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Re: Pipe size problems

A hard bend, like you get on a washing machine would prevent it. But how to get one to fit that pipe is another matter!

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Do you really need a working holding tank?

I installed a Vetus system in Greece lots of years ago because I was heading for Turkey... After that went up the ICW in the USA and messed around in NZ where I think they are also required - After using the tank once in a charter anchorage where folks were swimming I never used it again or had any official ask to see it..... Could just put a small tank in and a couple of leavers in case a custom official did ask - other than flotillas who are obliged I do not think many cruisers bother!!!

<hr width=100% size=1>If you have time please visit my web site -
<A target="_blank" HREF=http://www.michaelbriant.com/sailing>http://www.michaelbriant.com/sailing</A>
 
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