[Knut]

Someone here mentioned Company made water tables used air pressure to transfer the water from the tanks to the table. After viewing one water table and its fast water level adjustment, I presumed that is what it had. That zone member mentioned 2-3psi for this purpose.

I just completed a few glycol tanks for a customer, 9x12x72 in 12ga SS. In checking for leaks I kept it to 1psi as he claimed there would be no pressure on the tanks, BUT he said there would be no vent! I increased the pressure to 1.5psi just to examine the bulge on the 12" side. It was substantial and the load is of course 1500lb on the whole side at 1.5psi.

The tanks for my water table will be larger and not capable of handling anything near 2psi. Is the suggested pressure differential of 2-3psi wrong or should I be looking at using a small centrifugal pump to move the water? If it only has to raise it 1/2" to cover the sheet that's only 18 gal, a fairly short pump time between operations.

There is not enough room under the tipping table for round/tubular tanks.

Thanks for any suggestions,

Alan

[chuggins143]

Just lobbing this over the wall, but what about a 55 gal drum laid on its side? Put a hand valve on the bottom of the table where it's easy to get to, to dump water back into the tank when you want to remove your parts and just sit a sump pump in the tank that you can kick on when you want to raise the level. ...just a thought.
Chad

[jcc3inc]

Sir:

If you had a water depth of 12", the pressure at the bottom would be 62.5/144 or .43 PSI. Raising the water level 1" would result in no pressure increase. If you put an air chamber at the bottom of your 12" deep (for discussion purposes) tank, and raised the water level 1", the force on the bottom of the tank will be the same as before since the water volume is unchanged.

Regards,
Jack C.

[Knut]

Hi Jack C.,

I had not even even considered head pressure, but when the table and tank are connected for drainage the height of the water column is 2.5', just a bit over 1 psi. You need to transfer all of the water for the initial fill, so a bladder would not be used for that portion of the transfer. A bladder would be fine for 1/2" of adjustment, and removable for replacement through an access port. Of course you would still need to use either air pressure in the tank directly to fill the table, or a pump.

Using a submersible sump pump as Chad recommended will eliminate all that head pressure during transfer on the tanks, which in my case must be rectangular and rather tall to fit under the table. These thin tanks cannot take much more than the static head pressure of 1.1, they would probably blow at 1.5 psi.
The sump pump, something I already have a spare of, solves several problems and is remarkably fast at filling the table and changing water elevation. You also do not need careful air regulation to keep from inflating your tank during initial transfer.

Thanks again Jack and Chad,

Alan