Pump:
The misting pump creates the amount of water flow (volume of water). The motor creates the pressure. The pump (and motor) are housed in a single unit that controls water volume and water pressure. The water in your misting system needs enough pressure behind it to force it through the tiny nozzles that create the mist.
PSI:
As we work with water pumps, we find that pressure is presented to us in two common units: PSI (pounds per square inch) or feet of head. As we size a pumping system, we'll want to accomplish building pressure (PSI). The relationship between PSI and feet of head is that 2.31 feet of head = 1 PSI
The major Differnce Between the Pump:
300 PSI - These type pump is used for the medium purpose used where there is use of droplets of water EX: misting system for garding
100 PSI - these type pupm is used for the high level cooling environment .EX:Misting system for industeries and chillers
300 psi misting pumps are medium pressure misting pumps. bigger droplet size.
1000 psi misting pumps are High pressure misting pumps. tiny mist droplet size.