ISO 6162-1:2012

Overview

ISO 6162-1:2012 - Hydraulic fluid power - Flange connections with split or one-piece flange clamps and metric or inch screws - Part 1 defines general and dimensional specifications for flange connectors, ports and mounting surfaces used in hydraulic systems. It covers flange sizes DN 13 to DN 127 and working pressures from 3.5 MPa (35 bar) up to 35 MPa (350 bar). The standard specifies clamp types (split and one‑piece), screw options (metric and inch), O‑ring seal sizes and grooves, material and surface requirements, and pressure/temperature testing requirements.

Key topics and technical requirements

• Scope and sizes: Applicable for DN 13–DN 127 and pressures 3.5 MPa to 35 MPa; intended to avoid threaded connectors in hydraulic systems.
• Clamp types: Split flange clamps (FCS, FCSM) and one‑piece clamps (FC, FCM) with four-screw designs.
• Screw options:
  • Type 1 - accommodates metric screws (preferred for new designs).
  • Type 2 - accommodates inch screws (for legacy compatibility; not recommended for new designs).
• Materials & mechanical properties:
  • Flange clamps and heads: ferrous materials with specified minimum yield strengths (e.g., DN13 clamps min yield 220 MPa; other sizes min 415 MPa; flanged heads min 215 MPa).
  • Screws: typically property class 10.9 (ISO) or SAE grade 8 (inch).
• Seals: O‑rings conforming to ISO 3601‑1; default material NBR (nitrile) with hardness (90 ± 5) IRHD; grooves and seal dimensions are specified.
• Dimensions & tolerances: Detailed figures and tables define dimensions for clamps, heads, ports and O‑ring grooves; tolerances per ISO 2768‑1 (medium) unless otherwise stated.
• Corrosion protection & surface finish: Carbon steel parts require protective coatings (e.g., 72‑h salt spray for external surfaces); cadmium plating is not permitted; surface roughness and sealing surface requirements are defined.
• Testing: Flange connections must pass burst and cyclic endurance tests per ISO 19879. Design must account for pressure surges that can reduce sealing performance.

Applications and users

ISO 6162-1 is used by:

• Hydraulic system designers and OEMs specifying non‑threaded flange connections
• Component manufacturers (flanged heads, clamps, connectors, hoses)
• Quality and compliance engineers performing design verification and testing
• Maintenance and procurement teams matching replacement parts to existing flange pads and bolt patterns

Typical applications include industrial and mobile hydraulic equipment, commercial machinery, and any system where reliable, serviceable non‑threaded flange connections are required.

Related standards

• ISO 6162‑2 (high‑pressure variant, 42 MPa)
• ISO 3601‑1 / ISO 3601‑3 (O‑ring dimensions and quality)
• ISO 898‑1 (mechanical properties of fasteners)
• ISO 19879 (test methods for hydraulic connections)
• ISO 2768‑1, ISO 4017, ISO 4762, ISO 9227

Keywords: ISO 6162-1, flange connections, hydraulic fluid power, flange clamps, O-rings, metric screws, inch screws, DN 13 to DN 127, 35 bar to 350 bar.