ISO 6162-2:2018

Overview

ISO 6162-2:2018 - "Hydraulic fluid power - Flange connections with split or one-piece flange clamps and metric or inch screws - Part 2" specifies general and dimensional requirements for flange connectors, ports and mounting surfaces for hydraulic systems rated to 42 MPa (420 bar) for nominal sizes DN 13 to DN 76. The standard covers flanged heads, split (FCS, FCSM) and one-piece (FC, FCM) flange clamps, screw fastener options (metric type 1 and inch type 2), O‑ring seal dimensions and grooves, material and corrosion protection requirements, tolerances and selection guidance. These flange connections are intended where designers want to avoid threaded connectors in industrial and commercial hydraulic applications.

Key Topics and Requirements

• Working pressure and sizes: Rated for 42 MPa (420 bar), sizes DN 13–DN 76 (nominal flange size based on bore diameter).
• Clamp types: Split flange clamps (FCS/FCSM) and one‑piece flange clamps (FC/FCM) with four‑screw configurations.
• Fasteners: Supports metric screws (type 1) for DN 13–DN 76 and inch screws (type 2) for DN 13–DN 51. Note: type 2 inch ports are not recommended for new designs.
• Seals and grooves: Specifies O‑ring sizes per ISO 3601‑1, material default NBR (nitrile) hardness 90 ± 5 IRHD, and groove geometries; Annex B lists O‑ring designation codes.
• Materials & mechanical properties: Minimum yield/elongation requirements for clamps and flanged heads; recommended fastener property classes (e.g., ISO 4017, ISO 4762, SAE/ASTM equivalents).
• Corrosion protection: Coating requirements to meet minimum neutral salt spray durations (typically 72 h for external surfaces), and prohibition of cadmium plating.
• Dimensional tolerances: Finished part tolerances per ISO 2768‑1 (class m); detailed dimensions in figures and tables.
• Assembly & marking: Annex A gives recommended assembly procedures and screw torque guidance; marking and designation conventions are specified to avoid interchange with ISO 6162‑1.

Applications and Users

• Practical use: high‑pressure hydraulic systems in mobile equipment, industrial machinery, construction and material‑handling equipment where leak‑tight, non‑threaded connections are required.
• Who uses it: hydraulic system designers, OEMs, connector and hose manufacturers, maintenance engineers, procurement and compliance teams ensuring interchangeability and safety.
• Benefits: standardized flange connectors ensure reliable sealing, easy maintenance, compatibility across suppliers, and predictable mechanical performance at 420 bar.

Related Standards

• ISO 6162‑1 (other pressure class) - note: parts are not interchangeable
• ISO 3601‑1 / ISO 3601‑3 (O‑rings)
• ISO 4017, ISO 4762 (fasteners)
• ISO 2768‑1 (tolerances)
• ISO 9227 (salt spray corrosion test)
• SAE J429, ANSI/ASME B18.3, ASTM A574 (inch fastener specs)

Keywords: ISO 6162-2:2018, hydraulic flange connections, flange connectors 420 bar, DN 13 to DN 76, O-ring dimensions, metric and inch screws, flange clamps, high-pressure hydraulic systems.