Overview
SIST EN ISO 6149-2:2007 specifies the requirements for heavy-duty (S series) stud ends used in hydraulic fluid power systems and general applications, featuring metric threads in accordance with ISO 261 and O-ring sealing. This international standard, developed by CEN and ISO, sets out the dimensions, design guidelines, performance criteria, testing procedures, and marking requirements for both adjustable and non-adjustable heavy-duty stud ends.
These components are fundamental in connecting tubes, pipes, and fittings in high-pressure hydraulic systems. The standard covers stud ends designed for working pressures up to 63 MPa (630 bar) for non-adjustable types and up to 40 MPa (400 bar) for adjustable types, depending on size, material, and application.
Key Topics
- Metric Thread Compatibility
Specifies use of ISO 261 metric threads, ensuring global compatibility and standardization.
- O-Ring Sealing
Details requirements for O-ring dimensions, material properties, and quality acceptance to ensure robust sealing and reliable leak-free connections.
- Design and Dimensions
Provides precise dimensional data and tolerances for heavy-duty (S series) stud ends, supporting consistent manufacturing and interchangeability.
- Performance Requirements
Establishes burst and impulse pressure capabilities, emphasizing reliability in demanding hydraulic environments.
- Testing Methods
Describes test procedures including burst and cyclic endurance tests to validate component durability and compliance.
- Identification and Marking
Sets rules for component marking and identification, facilitating traceability and ensuring correct installation.
Applications
SIST EN ISO 6149-2:2007 is widely used in industries that rely on high-pressure hydraulic systems and fluid power technology, such as:
- Industrial Machinery
Standardizes connections in machinery with hydraulic actuators, power units, and pressure-driven controls.
- Mobile Equipment
Applied in construction, agricultural, and forestry vehicles where robust, high-pressure hydraulic fittings are essential.
- General Fluid Power Systems
Ensures safety and compatibility in pipelines, couplings, and flexible hose assemblies for both stationary and mobile installations.
- Maintenance and Retrofitting
Facilitates the replacement and servicing of hydraulic connections, ensuring continued system integrity and leak resistance.
Related Standards
SIST EN ISO 6149-2:2007 forms part of a broader family of standards for hydraulic and general-purpose connections. Notable related standards include:
- ISO 6149 Series
- Part 1: Ports with truncated housing for O-ring seal
- Part 3: Light-duty (L series) stud ends
- Part 4: Hexport plugs for sealing applications
- ISO 1179 Series
Ports and stud ends using ISO 228-1 threads with elastomeric or metal-to-metal sealing; still relevant for older systems, but not recommended for new designs.
- ISO 8434 Series
Metallic tube connectors, including 24° cone fittings and O-ring face seal fittings, commonly used alongside ISO 6149 components.
- ISO 19879
Specifies test methods for hydraulic fluid power connections (such as burst and cycle testing).
- ISO 3601-3
Quality acceptance criteria for O-rings used in fluid power systems.
By implementing SIST EN ISO 6149-2:2007, organizations can achieve safe, standardized, and efficient hydraulic connections, supporting reliability and global compatibility in fluid power and general use systems.
