Nozzles can be classified according to various criteria, including their function, material, industry, and shape.

(1) Based on nozzle function, they can be broadly classified into: spray nozzles, oil‑spraying nozzles, sand‑blasting nozzles, and special‑purpose nozzles.

(2) Classified by industry, they can be divided into: petrochemical nozzles, agricultural nozzles, textile nozzles, papermaking nozzles, printing nozzles, environmental‑protection nozzles (for desulfurization, denitrification, deamination, dust removal, etc.), coating nozzles, steel‑metallurgy nozzles, electronic nozzles, and food‑processing nozzles.

(3) Classified by material, they can be divided into: metal nozzles, plastic nozzles, alloy nozzles, and ceramic nozzles.

(4) Classified by shape, they can be divided into hollow-cone nozzles, solid-cone nozzles, square nozzles, rectangular nozzles, elliptical nozzles, fan-shaped nozzles, straight‑jet (direct‑flow) nozzles, two‑fluid nozzles, multi‑fluid nozzles, and so on.

Factors influencing nozzle selection include flow rate, pressure, spray angle, coverage area, impact force, operating temperature, material, and application; these factors are often interrelated and mutually restrictive. Nozzle performance is influenced by the materials used, manufacturing processes, and technological expertise involved in its production. However, in certain specialized environments requiring high‑temperature resistance or corrosion resistance, the material properties of the nozzle must meet particularly stringent requirements.