Fluid leveling by gravity

[Pedro_The_Swift]

Say you have two 200litre drums side by side,
they are connected at the bottom by a 50mm hose a metre long
Both drums are open to the atmosphere.

How fast can you fill both drums through the one opening?


Marks will be given to a "Litres per minute" answer.
Extra credit for providing the equation.

[Hogarthde]

Pedro, it depends entirely on the capacity of the meter [bigwhistle]

[V8Ian]

Depends on the fluid and the rate of filling. A 50mm hose will flow ~100 litres a minute @ 1 atmosphere.
What are you trying to do, fill the motorhome from one side?

[austastar]

Hi,
No idea, but the flow between the drums will be dependent on the difference of the fluid levels. So getting the receiving drum brimming as soon as possible will be the key.
Cheers

[Pedro_The_Swift]

Yes Ian, need to fill both sides tanks from one side...
at the truck hi-flow pump clickoff will both tanks be full??
We can ASSUME both tanks are at the same level to begin with....

[V8Ian]

Never Pedro, the easiest way is to fill each side from a different bowser, simultaneously.
I used to have a Western Star with 6x450 L tanks, three on each side; I had to run back and forth trying to brim each tank.
Usually balance hose is 12 or 19mm ID.
What fuel consumption are you getting?

[Graeme]

My truck only has a half-inch connecting hose which is effectively useless for filling the other side tank.

[Tins]

Yes Ian, need to fill both sides tanks from one side...
at the truck hi-flow pump clickoff will both tanks be full??


Off a hi-flow bowser?? Not a chance.

[Blknight.aus]

tricky,

need to know the orientation of the drums, are we talking 44 gallon drums stood on end or 200l fuel drums laying down like on a truck

which fluid, diesel, petrol, water, molassas?


stright though 50mm pipe/hose or does it have bends, curves or fittings, if its got fittings you need the ID of the fitting the hose goes onto as thats usually 5-10mm narrower in ID.

you cant answer the question without also knowing the available fill rate for the drum thats being used to fill the other drum. IF the transfer rate through the 50mm pipe significantly exceeds the fill rate for the first drum the answer is almost a simple

400l/fill rate.

if your fill rate is variable and it hugely exceeds the transfer rate of the pipe then the answer is very nearly the formula for filling the second drum through the 50mm pipe.

If your filling at those sort of rates, you wont get an ideal real world fill rate due to areation of the fluid going into the first drum....

All that said, using the epping Aldi high flow diesel pump, 2x220l MAN bus fuel tanks fill with a connected 60mm hose on 50mm id barbs and ball cock valve from nearly empty in ~7 minutes if I rely on the cross tank vent, ~5 if i open the fillers on both tanks.

[Pedro_The_Swift]

Thanks Dave, I hadnt thought about removing the tank cap on the other side... but it has to be vented anyway from the factory.
The filling necks are 100mm wide straight pipes, just like the old rangies

[Blknight.aus]

My MAN tanks for my auxillery fuel pod run a 13mm vent pipe between the tops of the 2 tanks so I dont need to open both sides to fill.

Therefore based on my 2x220l tanks (which are nearer 235 including ullage)

the formula for the time to fill is

440/7 =62.857142L/Min if I leave the other side cap on and
440/5 =88l/min If I open both filler caps.

naturally theres is slight variance if Im using the high flow bowser that has 2 dispensing sides and someone else is using the other side, temperature of the fuel, the day, if I manually hold the trigger or use the lock on setting 1,2 or 3, if I get distracted talking to the hot blonde and forget to trigger the pump, IF I forget to open the cross flow valve I closed off because I've been off roading and the pick ups only on one tank.


Now, about this extra credit........