ISO 2928:2021 Rubber hoses and hose assemblies for liquefied petroleum gas (LPG) in the liquid or gaseous phase and natural gas up to 2,5 MPa (25 bar) — Specification

ISO 2928:2021 Rubber hoses and hose assemblies for liquefied petroleum gas (LPG) in the liquid or gaseous phase and natural gas up to 2,5 MPa (25 bar) — Specification. b) Textile-reinforced hoses incorporating conducting materials: At least one electrically conducting layer shall be incorporated in the hose construction. The electrical conducting layer(s) shall consist of electrically conducting rubber materials. When attaching fittings to such hoses, an adequate connection between the fittings and the conducting layer(s) shall be ensured. When determined in accordance with ISO 8031, the resistance along the conducting layer(s), in the case of hoses, or the resistance between the fittings, in the case of hose assemblies, shall not exceed 1 x 106 fl per assembled length. When electrical continuity is demonstrated in this way, the hose shall be marked with the symbol fl. c) Wire-reinforced hoses: M hoses: Braided or spirally wound wire shall be incorporated in the construction and shall be in direct contact with the fitting. When determined in accordance with ISO 8031, the resistance between the fittings, in the case of hose assemblies, shall not exceed 1 x 102 fl per assembled length. When electrical continuity is demonstrated in this way, the hose shall he marked with the symbol M. 11 hoses: All incorporated metal parts shall not be connected with the fittings. When determined in accordance with ISO 8031, the resistance between the fittings, in the case of hose assemblies, shall not exceed 1 x 106 fl per assembled length. When electrical continuity is demonstrated in this way, the hose shall he marked with the symbol fl. d) Hose assemblies that are required to be discontinuous: Hose assemblies for this application are required to have an insulating layer between the metallic reinforcement/helix and either one of or both end-fittings. When tested in accordance with ISO 8031 the resistance between the end- fittings shall be greater than 2,5 x io fl per assembly. 9 Frequency of testing The frequency of type tests and routine tests shall be as specified in Annex B. Type test is obtained by the manufacturer demonstrating that all requirements of this document are met by a particular hose design manufactured by a particular method. The tests shall be repeated at a maximum of five-year intervals, or whenever a change in the method of manufacture or materials used occurs. Routine tests shall be carried out on each finished length of hose or...