Overview
ISO 4010:1998 defines a calibrating nozzle for diesel injection pump testing and setting on injection-pump test benches. The standard specifies the nozzle designation, key dimensions (based on ISO 2697 type B with two dowel holes omitted), marking and two approved test methods for determining needle clearances: Method 1 (clearance at the pintle) and Method 2 (clearance at the needle guide). Applicability to a given pump (typical range up to 150 mm/stroke) must be verified and stated on the pump test specification.
Key Topics
- Nozzle designation and marking: The nozzle shall be marked with the standard reference (ISO 4010) on the shank protruding beyond the cap nut.
- Dimensions and tolerances: Conform to ISO 2697 for type B except for the two omitted dowel holes; the needle-guide clearance is specifically defined by test method 2.
- Test method 1 - Clearance at the pintle (air flow):
- Measures clearance between the needle pintle and the nozzle hole by air flow.
- Flow measurements require calibrated devices with a precision of ±0.5 %.
- Control flow characteristics and specified control values are provided (flow vs needle lift); measurements must be corrected for ambient pressure and temperature to the reference conditions used in the standard (0.98 bar, +20 °C).
- Measuring installation includes a floating-body flowmeter, lift gauge, vacuum pump and reservoir; nozzle outlet pressure must be reduced below ambient (minimum specified pressure differentials in the standard) to ensure choked flow in the effective cross section.
- Test method 2 - Clearance at the needle guide (N2 gas-flow):
- Uses nitrogen gas flow at defined conditions (approx. 20 bar inlet pressure and +20 °C at nozzle entrance).
- Acceptable gas flow for new and used nozzles is specified (the standard sets a target range); it is recommended to repeat measurements twice after rotating the needle ~120° to verify consistency.
Applications
- Precise calibration and setting of diesel injection pumps on test benches.
- Quality control of calibrating nozzles and verification of injector components affecting pump performance.
- Use by pump manufacturers and test-lab engineers to ensure reproducible pump test results and compliance with pump test specifications.
Related Standards
- ISO 2697 (Road vehicles - Fuel nozzles - Size “S”) - referenced for dimensional conformity where applicable.
- ISO 7440-1 (Fuel injection equipment testing - Calibrating nozzle and holder assemblies) - listed in the bibliography.
This summary highlights practical aspects of ISO 4010:1998 relevant to test-lab procedures, nozzle selection and pump calibration. For implementation and exact numeric values refer to the official ISO 4010:1998 document and referenced standards.
