BS ISO 06605:2017 pdf download – Hydraulic fluid power – Test methods for hoses and hose assemblies
5.1.4.4 Take readings at 90° (1,57 rad) intervals around the hose.
Acceptability is based on the total variation between the highest and lowest readings. 5.2 Proof test 5.2.1 Test the hose assemblies hydrostatically to the specified proof pressure in accordance with the relevant product specification using the method specified in ISO 1402, for a period of between 30 s and 60 s for all sizes.
The proof pressure shall be twice the maximum working pressure, unless otherwise specified.
5.2.2 Hose assemblies that exhibit no leakage or other evidence of failure after being subjected to the proof test shall be deemed to have passed the test.
5.3 Change-in-length test
5.3.1 Conduct measurements for the determination of elongation or contraction on a previously unused, unaged hose assembly having a free length between hose fttings of at least 600 mm.
5.3.2 Attach the hose assembly to the pressure source in an unrestricted straight position. If the hose is not straight due to its natural curvature, it may be fastened laterally to achieve a straight position. Pressurize to the maximum working pressure for a period of 30 s, then release the pressure.
5.3.3 Place accurate reference marks 500 mm (lo) apart on the outer cover of the hose, midway between hose fittings, after allowing the hose assembly to restabilize for a period. of 30 s following pressure release.
5.3.4 Repressurize the hose assembly to the specified maximum working pressure for a period of 30 s.
5.3.5 Measure the distance between reference marks while the hose is pressurized and record this as l1.
5.3.6 Determine the change in length using Formula (1] in accordance with ISO 1402:
where lo is the distance between the reference marks after the hose assembly restabilizes pressurized following the initial pressurization and release of pressure, in millimetres; l1 is the distance between the reference marks while the hose assembly is under pressure, in millimetres; . Ot is the percentage change in length, which will be positive (+) in the case of an increase in length and negative [-) in the case of a decrease in length.
5.4 Burst test
5.4.1 General This is a destructive test. Hose or hose assemblies that have been subjected to this test should be destroyed.
5.4.2 Procedure 54.2.1 Subject unaged hose or hose assemblies, on which the hose fttings have been attached for less than 30 d, to a hydrostatic pressure. Increase the pressure at a rate in accordance with IS0 1402 until the hose or hose assembly fails. The minimum burst pressure shall be four times the maximum working pressure, unless otherwise specified in the pertinent hose product standard.
5.4.2.2 Reject hose assemblies showing leakage, hose burst or indication of failure below the specified minimum burst pressure.
5.5 Cold bend test
5.5.1 General
NOTE This test is technically identical to method B in ISO 10619-2. This is a destructive test. Hose assemblies that have been subjected to this test should be destroyed.
5.5.2 Procedure
5.5.2.1 Condition hose assemblies at a temperature equal to the minimum application temperature of the relevant product specification in a straight position for 24 h. 5.5.2.2 While still at the minimum application temperature, bend the samples once, taking a time of between 8 s and 12 s, over a mandrel having a diameter equal to twice the specified minimum bend radius. In the case of hose sizes up to and including 22 m.m nominal inside diameter, bend them through 180° over the mandrel; in the case of hose sizes larger than 22 mm nominal inside diameter, bend them through 90° over the mandrel.
5.5.2.3 After bending, allow the sample to warm to room temperature, visually examine it for cover cracks and subject it to the proof test (see 5.2) 5.5.2.4 Hose assemblies that exhibit no visible cracks, leakage or other evidence of failure after the cold bend test shall be deemed to have passed the test.
5.6 Cyclic endurance (impulse} test 5.6.1 General NOTE This test method is technically equivalent to that specified in ISO 6803. This is a destructive test. Hose assemblies that have been subjected to this test should be destroyed.
5.6.2 Procedure
5.6.2.1 Test hose assemblies with hose fttings that have been attached for less than 30 d.