ISO 6805:2020

Overview

ISO 6805:2020 specifies the requirements for wire-reinforced rubber hoses and hose assemblies specifically designed for underground coal mining hydraulic applications. Covering nominal hose sizes from 6.3 mm up to 51 mm, this standard ensures optimal performance and safety in demanding mining environments. It addresses compatibility with a range of hydraulic fluids including oil-based and water-based types, and specifies temperature ratings from −40 °C to +120 °C depending on the fluid used. The standard is critical for applications requiring durable, flame-resistant, electrically conductive hydraulic hoses that withstand harsh underground mining conditions.

Key Topics

• Scope and Fluid Compatibility
  ISO 6805:2020 applies to hoses for use with:

  • Oil-based hydraulic fluids (HH, HL, HM, HR, HV) as per ISO 6743-4, rated for -40 °C to +120 °C
  • Water-based hydraulic fluids (HFC, HFAE, HFAS, HFB) as defined in ISO 6743-4, rated for -40 °C to +70 °C
  • Water at temperatures from 0 °C to +70 °C
    Note: Hoses are not suitable for fluids with castor oil or ester base.

• Construction and Materials
  Hoses consist of a hydraulic-fluid-resistant rubber lining, multiple layers of steel wire reinforcement for mechanical strength, and an oil-, abrasion-, and weather-resistant rubber outer cover. The hoses must be electrically conductive and fire-resistant to meet safety regulations underground.

• Classification and Designation
  Hoses are classified by maximum working pressure and outside diameter, following ISO 18752, ensuring compatibility and interchangeability within mining operations.

• Performance Requirements

  • Electrical resistance must not exceed 2 MΩ/m, ensuring safety against static electricity build-up.
  • Flame resistance testing requires an average flame persistence time below 30 seconds, reducing fire hazards underground.
  • Abrasion resistance requirements are being developed to enhance hose durability under harsh mining conditions.

• Testing and Quality Assurance
  The standard mandates type and routine testing protocols including dimensional, mechanical, electrical, and flame resistance tests, with type tests repeated at least every five years or after design/manufacturing changes.

• Marking and Traceability
  Hoses and assemblies must be permanently marked with manufacturer’s identification, standard reference (ISO 6805), hose type, nominal size, maximum working pressure, and manufacturing date. This promotes traceability and ensures compliance within mining operations.

Applications

ISO 6805:2020 hoses are specifically engineered for the underground coal mining industry where hydraulic systems require robust and safe components. Typical applications include:

• Hydraulic power transmission for mining machinery
• Fluid conveyance in hydraulic support systems used in coal extraction
• High-pressure hydraulic operations in confined and hazardous underground environments
• Systems requiring flame-retardant and electrically conductive hoses to minimize ignition risks
• Environments where hoses must withstand abrasive conditions, mechanical stresses, and exposure to a variety of hydraulic fluids

Utilization of ISO 6805:2020 compliant hoses significantly enhances operational safety, equipment longevity, and regulatory compliance in underground mining activities.

Related Standards

ISO 6805:2020 references and aligns with several key international standards that govern hose performance and safety, including:

• ISO 6743-4: Classification and specifications for hydraulic fluids compatible with hoses
• ISO 18752: General specification for wire- or textile-reinforced single-pressure hydraulic hoses and assemblies
• ISO 8030: Test methods for flammability of rubber and plastic hoses
• ISO 8031: Methods for determining electrical resistance and conductivity of hoses
• ISO 8330: Vocabulary for rubber and plastic hoses and hose assemblies

Compliance with ISO 6805:2020 ensures integration and interoperability with these connected standards, providing a comprehensive framework for hydraulic hose safety and performance in mining.

Keywords: ISO 6805:2020, hydraulic rubber hoses, underground coal mining, wire-reinforced hoses, hose assemblies, electrical resistance, flame resistance, abrasion resistance, mining hydraulic hoses, oil-based hydraulic fluids, water-based hydraulic fluids, hose testing, hose marking, ISO mining standards.