Overview
ISO 7368:2025 - Hydraulic fluid power - Two-port slip-in cartridge valves - Cavities specifies the geometrical cavity dimensions and associated tolerances required to ensure interchangeability of two-port slip‑in cartridge valves used in industrial hydraulic equipment. The standard covers cavity layouts, port locations, fixing‑hole patterns and surface requirements, and defines size families (codes for sizes 06 to 16) and corresponding figures/tables for selection. It does not specify functional ratings such as pressure or flow.
Key technical topics and requirements
- Scope of data: Only geometric data for valve cavities and covers - ensures mechanical interchangeability across manufacturers.
- Cavity dimensions and size codes: Detailed dimensional tables and drawings for valve sizes (e.g., nominal port diameters for sizes 06, 08, 09 … 16) with reference figures (Figure 1–16 and Table 1–16).
- Tolerances and geometry:
- Positional tolerances for pin holes, screw holes and port holes: ±0.2 mm (with respect to datum axes).
- General tolerances per ISO 2768‑1.
- Surface roughness requirements (Rz values) as per ISO 21920‑1; unspecified finishes default to Rz 63 µm.
- Surface flatness requirement: 0.01 mm over 100 mm in accordance with ISO 3601‑2 for sealing surfaces.
- Specific features such as maximum corner radii at port bottoms, chamfers and no‑burr requirements in sealing areas.
- Symbols and coding: Port identifiers (A, B, X, Y, Z), fixing hole markers (F), pin‑hole locations (G) and the code system per ISO 5783 are used to standardize drawings and catalogue references.
- Identification statement: Offers the exact conformity text for catalogs and test reports: “Cavity dimensions conform to ISO 7368, Hydraulic fluid power - Two‑port slip‑in cartridge valves - Cavities.”
Practical applications and who uses this standard
- Hydraulic valve manufacturers: Design cartridge valves and covers to standardized cavity interfaces for cross‑manufacturer interchangeability.
- Manifold and system designers / OEMs: Specify cavity layouts and mounting interfaces on hydraulic manifolds to accept off‑the‑shelf two‑port cartridge valves.
- Maintenance engineers and procurement: Verify replacement cavity/valve compatibility, reduce downtime through standardized parts.
- Quality and test labs: Use the identification statement and dimensional tolerances for acceptance criteria and conformity documentation.
Related standards
Using ISO 7368:2025 helps ensure reliable interchangeability, consistent manifold design, and clearer communication between manufacturers, system designers and end users in hydraulic fluid power systems.
