Plastics hoses and hose assemblies - Textile-reinforced types for hydraulic applications - Specification (ISO 3949:2020, Corrected version 2020-12); German version EN ISO 3949:2020
1Key Takeaways
This document specifies requirements for three types of textile-reinforced thermoplastics hoses and hose assemblies of nominal size from 3,2 to 25. Each type is divided into two classes dependent on electrical conductivity requirements. They are suitable for use with: - oil-based
2Expert Interpretation
Professional interpretation of the technical requirements of the DIN EN ISO 3949:2021 standard for textile-reinforced thermoplastic hydraulic hoses, covering key performance indicators such as dimensional tolerance, burst pressure, and fluid compatibility for three types of hoses, R7/R8/R18. It is suitable for industrial application scenarios with oil-based hydraulic fluids from -40°C to +93°C and water-based fluids from 0°C to +60°C.
Key Points of Standard Core Changes
| Technical Parameters | 2020 Version Requirements | 2021 Version Changes |
|---|---|---|
| Volume Change Rate of Water Resistance Test | -10% ~ +25% | -15% ~ +35% |
| Volume Change Rate of Water-Based Liquid Resistance Test | 0% ~ +25% | -15% ~ +35% |
| Revision of R18 Hose Specifications | The third column of Table 6 repeats "R7 and R8" | Corrected to "R18" |
Hose classification system
The standard defines 3 types and 2 grades of textile reinforced thermoplastic hoses:
- Type distinction:
- R7 type: single or multi-layer reinforcement, maximum working pressure 10.5-21MPa
- R8 type: high pressure version, working pressure 14-42MPa
- R18 type: reference working pressure 21MPa (210bar)
1.0 - Test pressure: 31.4MPa(314bar)
- Minimum bursting pressure: 62.8MPa(628bar)
- Length change rate: ≤±3%@15.7MPa
- Pulse test: 150,000 times@125% working pressure
- Oil: HH/HL/HM/HR/HV hydraulic oil defined in ISO 6743-4, 100°C×72h
- Water-based fluid: Ethylene glycol/water (1:1) mixture, 70°C×168h
- Pure water: 70°C×168h
- Verify the integrity of hose markings: manufacturer name/ISO 3949 standard number/type grade/nominal size/maximum working pressure/production quarter
- Class 2 hoses must be marked "NON-CONDUCTIVE"
- The outer color should be RAL 2004 orange (surface marking is prohibited for Class 2)
Pressure Performance
Take R7 type 10mm hose as an example:
Material compatibility requirements
The volume change rate of the inner and outer layer materials after immersion in the following liquids must remain within the range of -15% to +35%:
Implementation recommendations
Purchasing considerations
Key points for quality control
| Test type | Required inspection items | Period |
|---|---|---|
| Type test | Burst pressure/pulse test/liquid compatibility, etc. | 5 years or when the material/process is changed |
| Factory inspection | Dimensions/static pressure test/appearance | Every 3000 meters or 12 months |