Diesel injector nozzles are the critical component of the fuel injection system — they determine spray shape, flow rate, and fuel distribution within the combustion chamber. The design and manufacturing quality of nozzles directly affect combustion efficiency, emissions, engine performance, and fuel consumption.

 Common nozzle types and designs

1. Pintle-type nozzle

Features a central pintle needle seating on a seat; fuel flow is controlled by the needle movement.

Common in older or medium-pressure diesel engines; relatively simple to manufacture and control.

2. Multi-hole (orifice-type) nozzle

It consists of several small holes arranged around the center. Produces fine atomization and even fuel distribution, widely used in modern high-pressure injection systems.

3. Single-hole nozzle

A single relatively large orifice, used in specific or older applications. Provides a particular spray pattern but is less versatile than multi-hole designs.