ISO 3949:2020

Overview

ISO 3949:2020 - Plastics hoses and hose assemblies - Textile-reinforced types for hydraulic applications - Specification - defines performance, dimensional and testing requirements for textile-reinforced thermoplastic hoses and hose assemblies. It covers three hose types (R7, R8, R18) in nominal sizes from 3.2 mm to 25 mm, divided into two electrical classes (Class 1: no electrical requirement; Class 2: non‑conductive). The standard applies to hoses used with oil‑based hydraulic fluids (HH, HL, HM, HR, HV) at −40 °C to +93 °C, and water-based fluids (HFC, HFAE, HFAS, HFB) and water at 0 °C to +60 °C. ISO 3949:2020 focuses on hose performance - it does not set requirements for end fittings and advises users to confirm fluid compatibility with manufacturers.

Key topics and technical requirements

• Classification: Types R7, R8 and R18 (R18 specified as 21.0 MPa working‑pressure based); each type split into Class 1 or Class 2 by electrical property.
• Materials & construction: Seamless thermoplastic lining and thermoplastic cover with textile yarn reinforcement. Class 2 covers must be unperforated and orange (RAL 2004).
• Dimensions & tolerances: Inside/outside diameters and concentricity measured per ISO 4671; tolerances given by nominal size and type.
• Pressure performance:
  • Proof, burst and maximum working pressures are specified per type and size (see Tables in the standard).
  • Hydrostatic testing per ISO 1402; change in length limits at working pressure (±3%).
• Dynamic tests: Impulse resistance per ISO 6803 (test fluid at 93 °C) and resistance to repeated hydraulic impulses.
• Flexibility & cold performance: Minimum bend radius and bend stiffness tests per ISO 10619‑1/2.
• Durability properties: Ozone resistance (ISO 7326), fluid resistance (ISO 1817), visual examination, and electrical conductivity testing (Annex D).
• Marking, testing frequency and documentation: Requirements for marking hoses/assemblies, routine and type testing, and test certificates.

Applications and who uses it

ISO 3949:2020 is intended for:

• Hose and hose‑assembly manufacturers (product specification, QC and testing)
• OEMs and system designers specifying hydraulic lines for mobile and industrial equipment
• Maintenance, procurement and safety engineers validating component performance
• Test laboratories conducting hydrostatic, impulse and electrical tests Typical applications include construction, agriculture, material handling, industrial hydraulic systems and any hydraulic application requiring textile‑reinforced thermoplastic hoses.

Related standards

Normative references include ISO 6743‑4 (fluid classification), ISO 1402, ISO 4671, ISO 6803, ISO 10619‑1/2, ISO 7326, ISO 1817, ISO 8330 and ISO 17165‑1. These are commonly used together when specifying, testing and certifying hydraulic hose assemblies.

Note: Always confirm fluid compatibility and fitting selection with the hose manufacturer before use.