OT: Physics/hydraulics of water and barrel

DUH! (slaps head)

You're right.

Maybe I'm completely missing something but it seems to me that going in thru the top will require less effort. Going in thru the bottom would only require less effort until the weight of the water pumped in exceeds the weight of the extra water columm if you go in thru the top.

For sake of argument, a half full drum of water will exert a fair amount of pressure com>

I'm pretty sure that town water towers ARE filled from the bottom.

As explained in a number of the previous posts in this thread, it takes less overall energy to fill a barrel (or water tower) from the bottom than from the top.

I was referring to the number of posts before it was pointed out.

Harry K

Three reasons for the bottom fill on towers (having spent more white knuckle time on those blatant lightning rods than I like to remember). First, those fill pipes are gated to perform in both directions from valves positoned on the ground (they also have flow restrictors for reverse flow). Second, the flow rates, especially during fill cycles, is high enough that wall friction is a significant factor so they keep them short and straight. Third, top fill in those big tanks causes some real nasty turbulence and wave problems where bottom fill is much more benign and predictable. I've also been told that running the pipe outside and up causes some appreciable balance and weight shift, but I'm skeptical of that one myself.

By the time this thread is d> I'm pretty sure that town water towers ARE filled from the bottom. >

LOL!

In that case we boil a couple gallons of water and add a bucket to the shower stall to sit on and sponge away!

Thanks All Who Participated. I understand now. I am going to use engineering instead of physics to solve this. I'll use the top hole in order not to have to risk losing the whole thing to gravity in a failure (it's or mine). Apparently the difference between the top and the bottom are negligable (i know that's not spelled right).

Thanks again.

Tom Greening proclaimed:

Yup, missing something. It takes exactly the same amount of energy to pump new water up into a bucket 1 foot wide as it would to pump water into a huge tank several miles wide. The depth of the water is all that matters...

For sake of argument, it would exert pressure exactly equal to the depth of water as long as the top of the water is open to air.

Nope. Height is pretty much it.

True, but that pressure is less than the pressure of a taller column of water...

Not at all uncommon to do just exactly that.

Ah, but for us pedants, there is no such thing as negligible ;-).

Harry K