ISO 3862:2020 pdf download – Rubber hoses and hose assemblies — Rubber-covered spiral-wire-reinforced hydraulic types for oil-based or water-based fluids — 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 Five types of hoses are specified, distinguished by their construction, working pressure and oil resistance: — Type 4SP: medium-pressure hoses with four plies of steel wire spiral. — Type 4SH: high-pressure hoses with four plies of steel wire spiral. — Type R12: heavy-duty high-temperature hoses with a medium-pressure rating having four plies of steel wire spiral. — Type R13: heavy-duty high-temperature hoses with a high-pressure rating having a multiple-steel- wire spiral. — Type R15: heavy-duty high-temperature hoses with an extra-high-pressure rating having a multiple- steel-wire spiral. 5 Materials and construction 5.1 Hoses Hoses shall consist of a rubber lining resistant to oil- or water-based hydraulic fluids or water, spiral plies of steel wire wrapped in alternating directions, and an oil- and weather-resistant rubber cover. Each spiral wire ply shall be separated by an insulating layer. 5.2 Hose assemblies Hose assemblies shall be manufactured using hoses conforming to the requirements of this document. Hose assemblies shall be manufactured only with those hose fittings whose correct functioning has been verified in accordance with 7.2, 7.4, 7.5 and 7.6. The manufacturer’s instructions shall be followed for the preparation and fabrication of hose assemblies.
7.4.2 Water-based fluid impulse test The impulse test shall be in accordance with ISO 6803 or ISO 6605. The test fluid temperature shall be 70 °C. The test fluid used shall be HFC, HFAE, HFAS or HFB as defined in ISO 6743-4. For type 4SP and 4SH hoses, when tested at a pressure equal to 133 % of the maximum working pressure, the hose shall withstand a minimum of 400 000 impulse cycles. For type R12 hoses, when tested at an impulse pressure equal to 133 % of the maximum working pressure, the hose shall withstand a minimum of 500 000 impulse cycles. For type R13 and R15 hoses, when tested at an impulse pressure equal to 120 % of the maximum working pressure, the hose shall withstand a minimum of 500 000 impulse cycles. There shall be no leakage or other evidence of failure before reaching the specified number of cycles. This test shall be considered a destructive test, and the test piece shall be discarded after the test. The following test can be used as an option to maximize test efficiency by reducing the amount of testing needed: a) oven-age assemblies filled with one of the water-based fluids specified in 7.4.2 for 120 h at 70 °C; b) impulse-test the aged assemblies using an oil-based hydraulic fluid as specified in ISO 6803 or ISO 6605 and the test conditions specified in ISO 6803 or ISO 6605.