BS EN ISO 3949:2020 pdf download.Plastics hoses and hose assemblies – Textile-reinforced types for hydraulic applications – Specification.
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 8330 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
4 Classification
Three types of hoses are specified, distinguished by their maximum working pressure:
a) Type R7: hoses with one or more layers of reinforcement;
b) Type R8: hoses with one or more layers of reinforcement, for operation at higher working pressures;
c) Type R18: hoses with one or more layers of reinforcement, 21,0 MPa (210 bar) working pressure based.
Each type of hose is divided into two classes according to its electrical properties:
— Class 1, no electrical requirements;
— Class 2, “non-conductive” (see 7.8).
5 Materials and construction
5.1 Hoses
Hoses shall consist of a seamless thermoplastic lining resistant to hydraulic fluids, with suitable textile yarn reinforcement and a thermoplastic cover resistant to hydraulic fluids, water and the weather.
For class 2 hoses, the cover shall not be perforated. The cover shall be orange (colour code RAL 2004).
5.2 Hose assemblies
Hose assemblies shall only be manufactured with those hose fittings whose functionality conforms to the requirements of 7.1, 7.4, 7.5 and, for class 2 only, 7.8.
6 Dimensions and tolerances
6.1 Diameters
When measured in accordance with ISO 4671, the diameters of the hoses shall conform to the values given in Table 1.
7 Physical properties
7.1 Hydrostatic requirements
When tested in accordance with ISO 1402 at the relevant proof pressure given in Table 3 and the
relevant minimum burst pressure given in Table 4, the hoses and hose assemblies shall not leak.
7.4 Resistance to impulse
7.4.1 The impulse test shall be in accordance with ISO 6803. The test fluid temperature shall be 93 °C.
7.4.2 For type R7 hoses, when tested at an impulse pressure equal to 125 % of the maximum working pressure, the hose shall withstand a minimum of 150 000 impulse cycles.
For type R8 and R18 hoses, when tested at an impulse pressure equal to 133 % of the maximum working pressure, the hose shall withstand a minimum of 200 000 impulse cycles.
7.4.3 There shall be no leakage or other malfunction before reaching the specified number of cycles.
7.4.4 This test shall be considered a destructive test and the test piece shall be disposed of in
accordance with local environmental guidelines.
7.5 Leakage of hose assemblies
When tested in accordance with ISO 1402, there shall be no leakage or evidence of failure. This test shall be considered a destructive test and the test piece shall be disposed of in accordance with local environmental guidelines.BS EN ISO 3949 pdf download.