Do RV water pumps require gravity feed to work?

[NM_Shooter]

I'm pondering my water system for my small cabin, and am considering using an RV water pump coupled with a 55 gallon water barrel for a storage tank. 

My water tank will be in the "crawl space" under my cabin.  I'm going to build an enclosure to house the water tank and my 12V battery bank.  I'd like to keep the RV pump above the tank in the cabin, which would put it approximately 5 or 6 feet above the tank. 

Can an RV pump draw a 6' head on the suction side?  Or do I need to put the pump down near the tank? 

Is there an alternative pump to use?  The water system serves a dish sink and a shower. 

Thanks,

Frank

[DaveOrr]

Hey Frank
I have done some research on this subject as I plan to use an RV pump for the water delivery in my cabin.
I am mounting mine above and beside my water tank.
The better quality pumps have the ability to draw to a 6' head like this high volume SHURflo 4048 pump.
In the specifications you can see it's self priming to 6' vertical.

Hit the features and benefits tab: http://shurflo.com/rv-products/rv-pumps/rv-fresh-water-pumps/shurflo-4048-high-flow-pumps/153-shurflo-4048-high-flow-pumps

[MountainDon]

They do self prime. My personal experience has been that the volume supplied at a fixture goes down as the head increases. IE the pump does have to work harder when lifting and that does decrease the output. I don't recall by how much, but I moved the pump to the same level as the tank outlet and liked it better.

[rick91351]

They do shove water better than lifting it.  IMHO

[UK4X4]

They don't have to have gravity feed

but they do prefer it !

Gravity feed ---higher flow, better system pressure, less wear , longer life

Can be operated by a pressure switch-ie on demand or off a switch with a circulating loop with taps etc off the loop.

[old_guy]

Keep in mind that the 6' (or whatever) head to the pump is from the lowest water lever you might ever have in the tank, not from the top of the tank.  Otherwise it might work fine when the tank is full, but not work when the level goes down just a little.