A spray nozzle is a device which makes use of the pressure energy of a liquid to increase its speed through an orifice and break it into drops.

Its performances can be identified and described precisely, so that the design engineer can specify exactly the spray nozzle required for a given process.

The relevant characteristics which identify the performances of a nozzle are the following:

  1. The liquid flow delivered as a function of the nozzle feed pressure.
  2. The opening angle of the produced spray.
  3. The nozzle efficiency, as the ratio between the energy of the spray and the energy used by the nozzle.
  4. The evenness of the flow distribution over the target.
  5. The droplet size distribution of the spray.