Valterra 7101 ABS Gate Valve, Black, 1-1/2" Slip

Can this be used as a backwash valve for an above ground saltwater swimming pool?

Can this be used as a dump valve for a 1600gallon non pressurized water tank? do you think it would leak with just that pressure from the water?

What is the diameter of the inlet? I need to know if this will fit onto my tank. Thank you.

Can this be used to drain a 500 gallon duck pond?