Rubber hoses and hose assemblies - Wire braid reinforced hydraulic type - Specification; German version EN 853:2015

Standard Overview and Revision Background

DIN EN 853:2016-09 is the technical specification for wire braid reinforced hydraulic hoses and assemblies published by the European Committee for Standardization (CEN), replacing the 1997 edition. This standard was developed by CEN/TC 218, Technical Committee for Rubber and Plastic Hoses and Hose Assemblies, with participation from the German Technical Standards Committee for Elastomers (NA 045-02-12 AA).

Hose types and structural characteristics

The standard specifies four types of wire braided reinforced hydraulic hoses:

All hoses are constructed with an oil and water resistant synthetic rubber inner liner, a high-tensile steel wire braid, and an oil and weather resistant rubber outer cover. Types 1SN and 2SN are designed for assembly to fittings without removing the cover or a portion of the cover.

Dimensional Accuracy Requirements

Hose dimensions must conform to the tolerances specified in Table 1, as measured according to EN ISO 4671:

The hose length tolerance is ±2% of the specified length. The hose assembly length tolerance is specified in sections based on the nominal diameter and length.

Performance Requirements and Test Methods

Hydraulic Performance Requirements

The maximum working pressure, proof pressure, and burst pressure of hoses and hose assemblies must comply with Table 4:

Pulse fatigue test

According to EN ISO 6803 tested at 100°C:
1ST/1SN type: ≥150,000 cycles at 125% of maximum working pressure for nominal diameter ≤25mm; ≥150,000 cycles at 100% of maximum working pressure for nominal diameter ≥31mm
2ST/2SN type: ≥200,000 cycles at 133% of maximum working pressure

Abrasion resistance test

According to the test method in Appendix A of the specification:
1ST/2ST type: Mass loss ≤1g after 2000 cycles under (50±0.5)N vertical force
1SN/2SN type: Mass loss ≤0.5g after 2000 cycles under (25±0.5)N vertical force

Material media resistance

Hose materials must meet the following media resistance requirements:

Major technical changes in the standard

Compared with the 1997 edition, the major changes in the 2016 edition include:
1. Update normative reference documents
2. Modify the inner diameter tolerance requirements (Table 1)
3. Add Appendix A for wear resistance test
4. Add Appendix B for type test and routine test
5. Add Appendix C for production acceptance test
6. Modify the wear resistance test details (Clause 6.8)

Scope of application and limitations

This standard is applicable to the following working media:
• Hydraulic oil specified in ISO 6743-4 (except HFD R, HFD S and HFD T), temperature range -40°C to +100°C
• Water-based fluid, temperature range -40°C to +70°C
• Water, temperature range 0°C to +70°C

Important limitations: Not applicable to castor oil-based and ester-based fluids, and must not be used beyond the working limits specified in the standard.

Quality control and testing requirements

Type test requirements

According to Appendix B, each type and specification of hose must be type tested in the following situations:
• Initial product certification
• After product changes
• Periodic inspection every 5 years

Production acceptance test

According to Appendix C, the tests required during the production process include:
• Dimensional measurement and verification pressure test every 3000 meters of production
• A full set of performance tests every 12 months

Marking and identification requirements

The hose must be marked with the following information every maximum of 500mm:
• Manufacturer's name or logo (such as XXX)
• This standard number 'EN 853'
• Type (such as 2ST)
• Nominal diameter (such as 16)
• Quarter and last two digits of the production year (such as 1Q15)

Example: XXX/EN 853/2ST/16/1Q15

Implementation Recommendations and Precautions

1. Selection Recommendations: Select the appropriate hose type based on the operating pressure, media type, and operating environment. Type 2ST/2SN is suitable for higher pressure applications.

2. Installation Precautions: The bending radius must not be less than the minimum value specified in Table 5. Avoid excessive bending that may cause flatness exceeding 10%.

3. Maintenance and Inspection: Regularly inspect the hose for surface wear. Replace immediately if the outer cover is worn to the point where the wire braid is exposed.

4. Compatibility Verification: When using non-standard hydraulic fluids, compatibility testing must be performed to ensure that it does not cause excessive expansion or performance degradation.

5. Quality Control: It is recommended to establish a comprehensive incoming inspection system and conduct dimensional measurement and verification pressure testing on each batch of hoses.

This standard provides comprehensive technical guidance for the selection, use and maintenance of hydraulic system hoses. The standard requirements should be strictly followed during implementation to ensure the safe and reliable operation of the hydraulic system.