How to Select a Spray Nozzle: A Step-by-Step Guide

Most nozzle problems come from a mismatch between the nozzle and the duty. Work through these steps and you will have everything needed for a correct selection.

1. Define the job

Write down what the spray must achieve: clean, cool, coat, humidify, scrub or suppress dust. This decides the pattern and droplet size range.

2. Choose the spray pattern

Full cone for even round coverage, hollow cone for finer droplets, flat fan for line coverage along a header, solid jet for impact, and fine mist for evaporation. See types of spray nozzles.

3. Fix flow and pressure

Decide the flow per nozzle (LPM) at the pressure available at the nozzle, not at the pump. Pressure losses in pipes and filters matter.

4. Check angle, distance and spacing

Coverage width equals roughly twice the distance times the tangent of half the spray angle, before gravity and air movement. Overlap adjacent sprays where uniformity matters.

5. Match droplet size to the process

Smaller droplets for evaporation and gas cooling; larger ones for washing and wetting.

6. Select material and connection

Brass, SS 304/316, PP, PVDF or PVC by liquid and temperature; BSP or NPT thread, or a clip-on for headers.

7. Plan for maintenance

Add filtration sized to the smallest passage and plan nozzle inspection. Worn orifices raise flow and spoil the pattern.