A weighted spray was developed to form a unique spray pattern that holds very constant velocity and consistent spray pattern regardless of flow, therefore, overcoming turndown problems in other spray nozzles. This is very useful in quenching or desuperheating service. Figure below illustrates this unique spray.

Knowing the pressure drop across the area producing spray in Ibs/inch^{2} and the lid contact surface in inch^{2}, one can calculate the weight in pounds. The pressure drop will be the pressure provided to the tee minus the vessel pressure.

The spray velocity can be calculated from Δh = u^{2}/2g, the units of which were previously defined. The velocity in ft/sec divided into the horizontal spray distance in feet gives the horizontal time component. The spray fall over that length of time is

S = 1/2gT^{2}

where

S = Fall distance in feet

T = Time in seconds

g = 32.2 ft/sec^{2}