150 ga tank and float

ws9876

There are a bunch of plastic tank manuf. on the web. Tons .What would you recommend for a 130-150 ga plastic tank for potable people water
with a quality float switch. Square would be better.The tank would receive low pressure water intermittently from about 100 ft away. It has to have an outlet at the bottom.I would want the  float switch to short the DC pump at about 90% capacity. thanks

Graham Parkinson

If it's going to be outside, make sure it's a black tank - white poly tanks grow algae and breakdown in sunlight.  The black tanks block UV which damages the plastic.  Square are more costly than round as the walls have to be thicker to resist water pressure.

ws9876

don't want to start another thread so......I need a 1/2 hp pump and saw the 4012 Flotec from Lowes for about 215$. The description mentions that you need an additional back valve to work with the pressure switch. I guess so it shuts off..????? Do you really need this?? Pressure switches switch off when you turn the faucet off, no???why  do you need anything else?

Graham Parkinson

I pump water uphilll once with a solar pump and then let gravity deliver it when needed, only needs a tank empty shutoff float switch to prevent pump damage (we also have a bit of a luxury, a shut off when upper tank full float switch too).

Don't know about the Flotec  pumps, but if you don't have a hill nearby, the next simplest is to have a pressure tank (water tank with rubber internal air bladder to allow pressurizing) and a pressure pump (positive displacement diagphram, RV pump etc.) with a pressure shutoff switch.   

If you open the tap pressure drops as water is dispensed.  At some point the pump comes on and refills the pressure tank.  The back valve you mention is to keep the pressure in the tank (just a spring loaded check valve).

Some 12 V RV style pumps have built in pressure reservoirs and pressure switches and even have their own check valves built in.  I don't know if they can deliver the same flow rates as a 1/2 hp pump which you might have to setup with your own tank and valves.

ws9876

regarding the pressure tank... does a Flotec or Sureflo 1/2 inch hp have a smart enough pressure switch so filling against the bladder
won't make it switch off too soon?Are they adjustable?
 I mean in a system that is not using a regular in line pressure switch but only using the built in one on the pump?The well pump is not controlled by a pressure switch..its a separate trickle DC system..

littleharbor2

They do have an adjustable pressure cut-out on the nose of the pump.  (nose, for lack of a better term)