ISO 7299-2:2021

Overview

ISO 7299-2:2021 - Diesel engines - End-mounting flanges for pumps - Part 2 - specifies dimensional requirements for end-mounting flanges used on high‑pressure supply pumps for common rail fuel injection systems in diesel (compression‑ignition) engines. This second edition updates the 2009 version and standardizes 10 types of pump end flanges (Types 1–10), including variants with tang drives. The document contains figures and tables giving flange geometry, hole positions and tolerances to support mechanical interchangeability.

Key topics and requirements

• Scope: Dimensional requirements for 10 end‑mounting flange types for high‑pressure supply pumps used in common rail systems.
• Flange types: Types 1–10 are defined; Types 2 and 5 explicitly include tang drive shaft arrangements. The 2021 edition adds Types 8, 9 and 10 to the previous seven types.
• Dimensions and tolerances: Detailed figures and tables provide flange diameters, mounting-hole patterns and axial/ radial dimensions. Engine manufacturers are recommended to use tolerance H7 for the female register diameter.
• Interchangeability: The standard enables consistent mechanical interfaces between pumps and engine housings by specifying nominal sizes, fits and hole configurations.
• References and conformity: Bibliography links related ISO standards used for threads, tolerances and shaft tapers (e.g., ISO 6519, ISO 286-2, ISO 261, ISO 965-1). The document contains no normative references but cross‑references established ISO dimensional practices.

Applications and users

Who uses ISO 7299-2:2021:

• Engine manufacturers (OEMs) designing the engine end for pump mounting and ensuring compatibility with supplier pumps.
• Pump manufacturers and suppliers specifying flange geometry to match common engine mounts and reduce variant counts.
• Tier 1 suppliers and integrators responsible for engine assembly, aftermarket retrofit kits and replacement pumps.
• Design, CAD and test engineers implementing mounting interfaces into 3D models, tolerance stacks and validation plans.
• Standards and procurement teams that require standardized interfaces to streamline sourcing and reduce development time.

Practical benefits:

• Promotes mechanical interchangeability of high‑pressure supply pumps in common rail diesel systems.
• Reduces design rework and tooling costs by aligning pump-to-engine interfaces.
• Supports supply‑chain flexibility and aftermarket compatibility.

Related standards

Relevant ISO documents cited in the bibliography:

• ISO 6519 - Diesel engines: tapers for shaft ends and hubs
• ISO 286‑2 - Tolerance classes for holes and shafts
• ISO 261, ISO 965‑1 - Metric screw thread dimensions and tolerances

Keywords: ISO 7299-2:2021, diesel engines, end-mounting flanges, high-pressure supply pumps, common rail, fuel injection systems, dimensional requirements, H7 tolerance, pump mounting, pump interchangeability.