Overview
ISO 7311:1993 specifies the mounting and connecting dimensions for heads for fuel filters with a vertical flange intended for diesel (compression‑ignition) engines. The standard defines hole positions, flange interfaces, port locations and dimensional tolerances so that fuel-filter heads and filter assemblies are interchangeable between engine manufacturers and filter suppliers.
Key topics and requirements
- Scope: Applies to heads for fuel filters with a vertical flange for diesel engines and covers both single and double filter arrangements.
- Mounting dimensions: Positions and tolerances for fixing holes and flange faces are given to ensure correct alignment and sealing between filter and head.
- Connecting dimensions: Locations of inlet/outlet ports (vertical and horizontal arrangements) are shown for common head types (e.g., single filter with vertical outlet + three horizontal ports; heads without a vertical outlet; 3‑ or 4‑port variants).
- Tolerances and units: Dimensions are provided in millimetres with specified tolerances; drawings and figure references illustrate exact layouts.
- Typical measurements referenced in the standard:
- Base flange diameters normally apply to filter cartridges with base diameter ≤ 80 mm (cartridges up to 88 mm may be accommodated in special cases).
- Recommended fixing hole centre spacing: 50 mm ± 0.5 mm (manufacturers encouraged to use this spacing).
- Common fixing thread for filter attachment: M16 × 1.5 (used as a general guideline in the text).
- Manufacturer options: Threads for regulation and venting valves are left to the manufacturer’s initiative; flange thickness variants (examples in figures) and single/double configurations are illustrated.
Applications
- Ensures interchangeability of fuel-filter heads and filter cartridges across engine models and aftermarket parts.
- Used in the design and verification of fuel systems for automotive, truck, bus and off‑highway diesel engines.
- Supports procurement, component standardization and service/maintenance tasks by providing clear mounting and connection specifications.
Who uses this standard
- Engine and vehicle OEMs (design and production engineering)
- Fuel-filter manufacturers and suppliers (product design and compatibility)
- Aftermarket and replacement part manufacturers
- Maintenance engineers, workshop technicians and parts procurement specialists
Related standards
Keywords: ISO 7311:1993, diesel engines, fuel filter heads, vertical flange, mounting dimensions, connecting dimensions, fuel filters, interchangeability, M16 × 1.5, 50 mm pitch.
Open preview (PDF)Diesel engines — Heads for fuel filters with vertical flange — Mounting and connecting dimensions
