SIST ISO 12151-2:2023

Overview

ISO 12151-2:2022 - Connections for hydraulic fluid power and general use - Hose fittings - Part 2 covers the design, dimensional and performance requirements for hose fittings that use ISO 8434-1 24° cone connector ends with O-rings. The standard applies to carbon steel hose fittings intended for hoses with nominal inside diameters from 5 mm through 38 mm (inclusive) and is intended for hydraulic fluid power systems and general pressure applications (braking-system fittings are excluded and referenced to ISO 4038 / ISO 4039).

Key topics and technical requirements

• Scope and applicability: Fittings with 24° cone connector ends and O-rings per ISO 8434-1 for hoses 5–38 mm ID.
• Performance: Hose assemblies must meet the performance requirements of the relevant hose specification; working pressure is the lower of the values in ISO 8434-1 and the hose standard.
• Design & dimensions: Dimensional conformity to the figures and tables in the standard; hex tolerances per ISO 4759‑1 (product grade C); elbow axis angular tolerance ±3°.
• Materials & manufacture: Carbon steel standard; other materials permitted by agreement. Construction methods include forging, cold forming or machining; workmanship and surface roughness requirements (ISO 1302 MRR Ramax 6,3 µm for machined surfaces).
• Corrosion protection: External surfaces and threads should be plated/coated to pass a 72‑h neutral salt spray test (ISO 9227), with defined exceptions.
• Assembly & instructions: Manufacturers must provide assembly instructions (number of wrenching turns or assembly torque, tool recommendations). Assembly must be without external loads.
• Designation & marking: Standardized alphanumeric designation format (e.g., ISO 12151-2 - SWS - L22 × 19). Fittings must be permanently marked with manufacturer’s name/trademark; swivel nuts marked with series (L or S) and connection size.
• Procurement information: Minimum purchaser-supplied data includes fitting designation, hose type/size, fluid, working pressure and temperatures.

Applications and users

• Typical users: hydraulic system designers, hose and fitting manufacturers, procurement teams, maintenance engineers, and test laboratories.
• Practical uses: specifying compatible hose fittings for hydraulic machinery, mobile equipment, industrial fluid-power installations and general high-pressure hose assemblies where ISO 8434‑1 cone/O‑ring connections are required.
• Benefits: ensures interchangeability, predictable performance, corrosion protection standards and clear procurement/marking requirements.

Related standards

• ISO 8434-1 (24° cone connectors) - direct connector requirements referenced.
• ISO 5598 (vocabulary), ISO 1302 (surface texture), ISO 4759-1 (hex tolerances), ISO 9227 (salt spray test).
• Note: braking-system fittings referenced to ISO 4038, ISO 4039-1 and ISO 4039-2.

Keywords: ISO 12151-2:2022, hose fittings, 24° cone connector, O-rings, hydraulic fluid power, carbon steel, ISO 8434-1, working pressure, corrosion protection, assembly instructions.