Help with water pressures

[CampervanJames]

Hello, I’m about to embark on a campervan conversion, I need to carry a considerable amount of fresh water to supply taps and shower, I’m intending to use 6x 25l water drums, from these 6 drums I’m hoping to be able to connect them up in unison so 6 hoses running to the bottom of each drum and then joining to one feed pipe to a pump, I imagine that the force of gravity will mean that all 6 drums will empty evenly, if I’m wrong on this please correct me? This however is not my question or at least not the question I’ve really come here to ask. 

So what I’m really wanting to know is whilst it would be feasible to remove each drum to refill I wondered if it would be possible to fill the drums up in situ by adding a hose pipe along with some valves to change from the feed to the pump to an inlet for a hose pipe, I’m assuming that using the same hoses that go to the bottle of the drums as the drums would fill there would be an increased amount of pressure needed to fill them due to the gravity of the water above the bottom of the hoses and wonder whether the pressure from a typical water mains would be sufficient to overcome this?

Alternatively I considered adding an extra hose to each drum that doesn’t go all the way to the bottom for filling purposes, I expect in doing this I would still need to go down a bit to insure they also fill evenly?

Any thoughts on this would be greatly appreciated, thanks.

[Klaynos]

Yes, I think this is feasible. You'll obviously have to ensure that air can get in and out the battles as quickly as the water. You might also want to connect them together nearer the top to try and more easily deal with differing levels. What I'm going to call balancing will be critical, else you'll have one empty tank and start pumping some air on outflow and on inflow you'll have water pouring out the top of one before the others are near full. 

A better idea (to get around the balance problem) would be to have each one tapped individually. You would then fill and empty each one on its own avoiding the balancing problem. You could even automate that if you were so inclined.

 

Oh and to answer the pressure question. 1 bar will raise water by 1 m. So to fill a 1 m high barrel which is 1 m off the ground you need more than 2 bar. In the UK domestic water pressure is around 10 bar which is enough to easily lift water into the loft spaces of most houses. Filling from the bottom with a pressure close to the minimum requirement would b come very very slow though. That's one of the reasons why cisterns in houses fill from the top even if though there is enough pressure to not. 

[Endy0816]

Is rigging up a siphon an option?