Three procedures for assessing the integrity of hydraulic hose/coupling connections were developed and shown to be effective methods for detecting hose failures induced by improper coupling connections. Each procedure's sole purpose is to detect one or two specific failure modes of hose assemblies.
The development of these procedures arose from a need to quantitatively measure hose/coupling integrity. The three test procedures are the Mechanical/Hydrostatic Coupling/Hose Separation Test (FPRC-LH-S22), the Pneumatic Surge Test (FPRC-LH-S21), and the Progressive Leakage Test (FPRC-LH-S4). The results of each test yield not only failure modes, but a means for quantitative integrity rating. The Hose Assembly Rating is a test-dependent measure developed to scale all test results from 1 (poor) to 10 (excellent). This rating provides a means for expedient, direct comparison of test results.
The use of these test procedures has proved invaluable. Their capability to isolate hose assembly failure modes has enabled reconstruction of actual hose failures. This is especially important with the rise of manufacturer liability. Additionally, new hose/coupling assemblies can be quickly assessed and unsatisfactory areas of design easily detected.
Each of the 3 hose coupling integrity tests, run 48 times each, compares the results of 8 different hose/coupling manufacturers. Test findings are repeat-able, reproducible, and tracable to a specific failure mode. Results indicate that a great deal of room remains for improvement of hydraulic hose assemblies.