Hydraulic fluid power — Two-port slip-in cartridge valves — Cavities
1Key Takeaways
This standard provides specifications for the measurement of hydraulic oil power in double-port spool valves with seat characteristics. It outlines the procedures and requirements for testing and evaluating the performance of such valves under specified conditions. The document covers essential parameters related to th…
2Expert Interpretation
An in-depth analysis of ISO 7368:2025, the international standard for hydraulic two-way cartridge valve cavities, covers the geometric dimensions, tolerance requirements, and technological evolution of 16 valve cavity sizes, ensuring valve body interchangeability in industrial hydraulic systems. A standard comparison table and implementation recommendations are provided.
Analysis of the core content of the standard
The third edition of ISO 7368:2025 comprehensively regulates the geometric parameters of the installation cavity of two-way hydraulic cartridge valves. The main updates include:
| Technical parameters | 2016 edition | 2025 edition | Explanation of changes |
|---|---|---|---|
| Datum system | Reference diameter d1 only | New datum B (verticality of valve block surface) | Reduce the error caused by the short measurement distance of d1 |
| Rounded corners of outer diameter d2 | No mandatory requirement | R2 fillet is uniformly increased | Improve sealing surface reliability |
| Depth Z tolerance | Not standardized | Uniformly ±0.2mm | Harmonized with ISO 5783:2019 |
Key dimension system
The standard covers 16 specifications of valve cavities (sizes 06-16), with the following main technical features:
- Sealing surface roughness: Rz≤6.3μm (within the chain line area)
- Geometric and positional tolerances: Flatness 0.01mm/100mm (ISO 3601-2)
- Port identification: A/B main oil port, X/Y pilot oil port, Z1/Z2 auxiliary pilot port
Typical application case
Key points for the implementation of size 10 valve cavity (40mm main oil port) in construction machinery:
- The valve block material must meet the pressure resistance requirements of ISO 4413
- The surface quality of Rz6.3 must be guaranteed in the chain line area of the installation surface
- The depth of the fixing screw ≥1.8D (M20 screws must be more than 36mm)
Implementation suggestions
Technical extension requirements based on the standard:
| Implementation links | Key control points | Test method |
|---|---|---|
| Processing and manufacturing | H7 tolerance zone control of d1/d2 | Coordinate measuring machine |
| Assembly and debugging | Screw torque value (M12:85-100Nm) | Digital torque wrench |
| Maintenance and replacement | Sealing surface Rz re-measurement | Surface roughness meter |
Note: The standard does not involve rated pressure parameters. System pressure verification must be carried out in combination with ISO 4413.