Joining Pump Out Tanks

[Old Son]

I have a friend with a wide beam who currently has a 250 litre pump out tank fitted under his bed. He wants to either add a similar size tank to the existing to double the capacity or take out the existing tank and fit a larger one.

 

Adding a similar size tank will be less hassle and an easier fit. If he fits a new tank it will mean rebuilding his bed.

 

Has anybody added an additional tank? What is the best method of connecting the additional tank? What size connections would be required and would a separate air vent be required for the second tank?

 

Thanks

[Alan de Enfield]

No experience of doing this but 'engineering wise' I'd suggest the following :

 

Put 2nd tank on the opposite side of the boat or you are adding another 1/4 tonne to the same side.(trim problems ?)

You may need to add ballast to the front of the boat (assuming tank is towards the rear)

Put as large a diameter pipe as possible ( 3" ?) between the tanks to ensure 'smooth flow' and minimise potential blockages.

Put in an additional pump-out point - I'm not sure how efficiently a P/O would suck from tank A to tank B

Put in another breather for tank B

Think about the possibility of a 'stop-tap' between the two tanks

Edited April 22, 2014 by Alan de Enfield

[Kae]

Considering the issues peeps have with just the one tank and its associated connections, I'd go for one larger tank. Less to go wrong!

[bottle]

The interconnecting pipes will not be at the lowest point so only having one pump out point would mean that one tank would always have some residue left.

 

Having two pump out points may incur a second charge for a pump out.

 

See previous posts #2 and #3.

[Paul's Nulife4-2]

Hi ya,

If going down the adding a 2nd tank route,

& Taking into account Weight / Trim ect, I would actually Fit 2 or more Large diameter Connection / Equalization Outlets from the 1st to the 2nd Tank, Both with Stop Taps, and don't forget to Vent (crucial) & Plumb for Rinseing of the 2nd Tank independently as well. & if going to all that trouble, you might as well fit Deck Gear for Emptying as well, So you can get Pumped out from Either Side.

I have to be honest,, it may be easier to put a bigger tank in, That would be a lot of Shxt.

Edited April 22, 2014 by Paul's Nulife4-2

[Old Son]

Thank you for your replies. I am beginning to think you are all correct. If the tank was changed for a larger one it would save a lot of possible plumbing issues. I am sure he could have a tank made to fit under the existing bed construction.

Where would be the cheapest place to have a plastic tank made to fit?

[BlueStringPudding]

Hi ya,

If going down the adding a 2nd tank route,

& Taking into account Weight / Trim ect, I would actually Fit 2 or more Large diameter Connection / Equalization Outlets from the 1st to the 2nd Tank, Both with Stop Taps, and don't forget to Vent (crucial) & Plumb for Rinseing of the 2nd Tank independently as well. & if going to all that trouble, you might as well fit Deck Gear for Emptying as well, So you can get Pumped out from Either Side.

I have to be honest,, it may be easier to put a bigger tank in, That would be a lot of Shxt.

Out of curiosity, why would the tank (either of them) need separate plumbing for rinsing and pumpout? Surely both can be done through the same deck fitting? That's how my tank (and therfore a fleet or two of Black Prince hireboats) were designed.

[Paul's Nulife4-2]

Well if you had two tanks, connected via a cpl of large diameter Equalizing pipes situated towards the bottom of the tanks, to allow for better Filling,Equalizing & Emptying, how will the top 7/8ths of the 2nd tank get rinsed out if only the 1st tank is plumbed for Rinse !. It would just swoosh around the 1st tank and doubt it would even enter the 2nd tank at all !. Unless you Fitted a Second Deck Fitting for the 2nd tank as I suggested.

Try Drawing it on a piece of paper, it might make more sense than my babble !.

 

Nothing wrong with a single Deck fitting. But many, including mine has got a seperate Rinse Pipe,that normally enters the top of the tank, and acts more like a mini Sprinkler system.and keeps the rinse hose clean,as it only ever goes in a clean rinse Deck Fitting.

Edited April 22, 2014 by Paul's Nulife4-2

[Paul's Nulife4-2]

Thank you for your replies. I am beginning to think you are all correct. If the tank was changed for a larger one it would save a lot of possible plumbing issues. I am sure he could have a tank made to fit under the existing bed construction.

Where would be the cheapest place to have a plastic tank made to fit?

And don't forget, every joint is a potential leek !

[Old Son]

In reality all a rinse pipe does is wet the bottom of the tank to try and dislodge any sludge that might be there. I don't know anybody who fills their tanks with clean water to 'rinse' during a pump out. I am sure you would run out of time on the machine and be left with half a tank of water!!

[dmr]

I really would bite the bullet and fit the bigger tank.

The connecting (balance) pipe between the two tanks would have to be at the bottom of the tanks so any leaks at the connections will fill you boat with very unpleasant brown liquid. Trying to have a balance pipe out of the top of the tank will create all sorts of issues as the first tank would need to hold the full vacuum of the pump out machine to empty the second tank. Having two totally separate tanks with separate loos and separate pump out connections (like many hire boats) is the other option.

 

...........Dave

[Paul's Nulife4-2]

In reality all a rinse pipe does is wet the bottom of the tank to try and dislodge any sludge that might be there. I don't know anybody who fills their tanks with clean water to 'rinse' during a pump out. I am sure you would run out of time on the machine and be left with half a tank of water!!

No, i dont know anyone that FILLS there tank withe clean water to 'rinse'during a pumpout either !.

But I do uses Fresh water from my Own Boat Fresh waterTank via my Aft Deck Shower Hose, which is then fitted to a 'Leesan' ADAPTER (part number 01419) that then screws into my 'Leesan RINSE out Deck Fitting (part number 02049 in S/S) and turned on to Rince WHEN the Yard Pump out has finnished sucking (Tone Changes when empy) but is STILL CONNECTED to my 'Leesan PUMP out Deck Fitting, Thus sucking out the BURST of FRESH RINSE water that enters the top of the tank and sprays around most of the internal areas and keeps the Sender for the gauge clean BEFORE hitting the bottom of the tank it'self. It's also worth remembering that the 'Pick up Pipe' or 'Suction pipe' inlet for discharge, is Hovering towards the BOTTOM of the Tank! (Well it is on mine anyway) So RINSING from the PUMPOUT Deck fitting, will probably do very little other than clean locally to the end of the Pick up pipe..

But I guess we all do it different,

Ime a great believer in, if it works for you then carry on.

Edited April 23, 2014 by Paul's Nulife4-2

[Paul's Nulife4-2]

So, out of interest,,How do you Rinse or Clean your tanks ?

[blackrose]

I think any pipe connecting the two tanks should be a fairly big diameter in order to prevent a large turd blocking the pipe.

[J R ALSOP]

Dead easy with a Porta Loo, just pick it up and shake.

[Old Son]

So, out of interest,,How do you Rinse or Clean your tanks ?

My tank has the take off at the bottom so when I stuff the special piece of hose I have down my pump out pipe all it actually does is wet the bottom of the tank. I leave it in there for about 3 minutes during which I rock the boat to try and stir the remnants in the tank. I do use Bio Magic so I don't seem to get many solids when it comes to pump out time.

 

I take on board everything everybody has said and I think the only way to go is fit a larger tank!!

[Wanted]

I think any pipe connecting the two tanks should be a fairly big diameter in order to prevent a large turd blocking the pipe.

Back log?

[Paul's Nulife4-2]

Back log?

Oh, that's just Foul stuff Wanted!.

[BlueStringPudding]

My tank has the take off at the bottom so when I stuff the special piece of hose I have down my pump out pipe all it actually does is wet the bottom of the tank. I leave it in there for about 3 minutes during which I rock the boat to try and stir the remnants in the tank. I do use Bio Magic so I don't seem to get many solids when it comes to pump out time.

 

I take on board everything everybody has said and I think the only way to go is fit a larger tank!!

Yup. That's how the boatyards have always done it with my boat so that's how I do it too.

[DeanS]

I read the title as meaning ....you had decided to jump from the casette "group" to join the "pumpout group", and my heart was filled with sadness that someone would make such a terrible decision

 

 

 

morning all.

[patty-ann]

Yep thats how I read it too...so have to read the thread out of curiosity as to Why?? I now find myself still wondering Why some one wants 2 pump out tanks, all that s... storage..phew!

[Paul's Nulife4-2]

Old Son

BSP

 

Aahh,, The Old Rinse & Shake ploy ay,

 

Oh No no no Dear Chaps, (& Chap esses), Far to energetic for the likes of me, All that Rocking & Rolling,Shaking & a Wobbling would knock my Donuts off the counter top, and Spill my Cider, & I can't have that !. I just connect, wait for Tone to change, Turn the Rinse on count to 20, turn off, Dis connect, whilst chatting to the pumpout operator and Sat on my Aft Deck, The Whole Process from Start to Finnish only takes

6/8 mins All very civilized !..

 

I put a pic on the Gallery of my Pump out & Rinse out Deck fittings, for you to admire over your morning Cuppa & Toast !.

Edited April 24, 2014 by Paul's Nulife4-2

[Old Son]

Yep thats how I read it too...so have to read the thread out of curiosity as to Why?? I now find myself still wondering Why some one wants 2 pump out tanks, all that s... storage..phew!

 

The reason for additional storage is because the pump out station at our marina runs for 11 minutes. You cant stop it half way through. While it is pumping out 125 litres it might as well pump out 250 litres. Its the same price, in fact he will only need to visit the pump out half as many times so will save money!! No smell by the way, its all plumbed in and vented correctly.

[Alan de Enfield]

 

The reason for additional storage is because the pump out station at our marina runs for 11 minutes. You cant stop it half way through. While it is pumping out 125 litres it might as well pump out 250 litres. Its the same price, in fact he will only need to visit the pump out half as many times so will save money!! No smell by the way, its all plumbed in and vented correctly.

 

Now I'm confused - how big is the existing tank in the Original Post it was stated :

 

Posted 22 April 2014 - 09:13 AM

I have a friend with a wide beam who currently has a 250 litre pump out tank fitted under his bed