Holding tank location question?

[er9]

I have a large locker in my head im considering moving my holding tank to. Its large enough i think i can squeeze in a 15-20 gal tank and get rid of the large tank in the v-berth.

If i do the inlet for the tank will be about two feet above the toilet discharge pipe and about the same distance above the waterline.

Will i be able to manually pump liquids and solids to that height? I have a Jabsco manual pump toilet.

[S/V Illusion]

Can you? Yes, it is possible. However, it isnt a good idea as the only thing which stands between the holding tank content and the interior of the boat is a valve which can often leak or fail catastrophically especially if it's higher than the head.

[Allied39]

Above the waterline perfect spot. You can easy pump into it but best of all you can drain the tank via gravity.
No pumps to fail, no macerator to (pardon the pun) take a sh#t.
I have had mine in a location like this for 20 years, never a problem, no fails, catastrophic or otherwise.
I installed mine so I could close the valve directly off the tank and remove the tank full if needed. But it has never been needed.
Oh, and an absolutely awesome feature is when on a port tack I can open the valves so sea water pushes into then out of the tank. I can flush the tank, well for as long as I am on a port tack.
Like a cleanable holding tank? I do.
This post is for the OP, dont care to argue or deal with trolls.

[er9]

S/V Illusion are you talking about the rubber back flow valve thats in the discharge line that exits the toilet?

i thought about that and figured i could do two things to help prevent that. plumbing the inlet into the holding tank into the top of the tank and adding a gate valve into the line that enters the top of the tank to prevent any back flow during sailing.

i guess my biggerst concern was if the manual pump toilet could physically push the contents that high above the toilet. the relief valve/loop plumbed in right now is about a foot lower than what it would be if i relocate the tank.

[er9]

Originally Posted by Allied39

Above the waterline perfect spot. You can easy pump into it but best of all you can drain the tank via gravity.
No pumps to fail, no macerator to (pardon the pun) take a sh#t.
I have had mine in a location like this for 20 years, never a problem, no fails, catastrophic or otherwise.
I installed mine so I could close the valve directly off the tank and remove the tank full if needed. But it has never been needed.
Oh, and an absolutely awesome feature is when on a port tack I can open the valves so sea water pushes into then out of the tank. I can flush the tank, well for as long as I am on a port tack.
Like a cleanable holding tank? I do.
This post is for the OP, dont care to argue or deal with trolls.

thanks thats good to know it works then. it would free up a ton of space in the v-berth for storage and no matter how hard i try i cant eliminate that faint odor which i no longer want in the v-berth where i sleep. would love to be able to contain that all in the head.

[SVHarmonie]

Originally Posted by er9

S/V Illusion are you talking about the rubber back flow valve thats in the discharge line that exits the toilet?

i thought about that and figured i could do two things to help prevent that. plumbing the inlet into the holding tank into the top of the tank and adding a gate valve into the line that enters the top of the tank to prevent any back flow during sailing.

i guess my biggerst concern was if the manual pump toilet could physically push the contents that high above the toilet. the relief valve/loop plumbed in right now is about a foot lower than what it would be if i relocate the tank.

ER9,

You are 100% correct. If you pump to the top of the tank, there is NO risk of draining the tank back to the toilet. If the check valves in the toilet fail, all that drains back is the "stuff" in the hose between the toilet and the tank, so make sure that length of hose doesn't contain more "stuff" than the bowl can hold. There is no need for a valve, that will only cause you trouble for no benefit.

Another common arrangement is for the inlet to be piped to the bottom of the tank, and then a standpipe carries it to the top inside the tank. Either one works, and it depends on the piping access which to use.

As for a manual Jabsco toilet, they are used in this service ALL the time. The arrangement you describe is very common. On our boat the base of the manual Jabsco toilet is about 1.5 meters below the top of the tank when it enters. It pumps with no issue at all.

[er9]

Originally Posted by SVHarmonie

ER9,

You are 100% correct. If you pump to the top of the tank, there is NO risk of draining the tank back to the toilet. If the check valves in the toilet fail, all that drains back is the "stuff" in the hose between the toilet and the tank, so make sure that length of hose doesn't contain more "stuff" than the bowl can hold. There is no need for a valve, that will only cause you trouble for no benefit.

Another common arrangement is for the inlet to be piped to the bottom of the tank, and then a standpipe carries it to the top inside the tank. Either one works, and it depends on the piping access which to use.

As for a manual Jabsco toilet, they are used in this service ALL the time. The arrangement you describe is very common. On our boat the base of the manual Jabsco toilet is about 1.5 meters below the top of the tank when it enters. It pumps with no issue at all.

fantastic! this is good news since its time to tear up the v-berth. Much thanks for the tips on plumbing.

[Bill Seal]

Sort of OT, but I'm thinking about making a custom plywood tank and lining it with several layers of GRP. I have an old (never used) Jabsco macerator head and figured that since the poo is pre-ground I could use a 1" line to the tank and therefore use less water.
Am I missing something?
The bottom of the tank would be above the existing -now closed- through hull and be gravity draining.

[gonesail]

it may be ground up when it goes into the tank .. but gravity also compresses the waste that settles at the bottom of the tank. and it can become solidified there and not be able to empty itself with gravity. and this is a documented and pretty ugly situation as well.