Vibration test. The valve unit is pressurized to its 100 per cent NWP (+2/-0 MPa) with hydrogen, sealed at both ends, and vibrated for 30 minutes along each of the three orthogonal axes (vertical, lateral and longitudinal) at the most severe resonant frequencies. The most severe resonant frequencies are determined by acceleration of 1.5 g with a sweep time of 10 minutes within a sinusoidal frequency range of 10 to 40 Hz. If the resonance frequency is not found in this range the test is conducted at 40Hz. Following this test, each sample shall not show visible exterior damage that indicates that the performance of the part is compromised. At the completion of the test, the unit shall comply with the requirements of the ambient temperature leak test specified in Annex 4, paragraph 2.2.
Vibration test. Vibrate the gas tube and its coupling(s) according to the test described in Annex 16, paragraph 10.5.4., procedure A. After this test the gas tube and its coupling(s) need to comply with the leakage test of Annex 16, paragraphs 5., 6. and 7. and with the overpressure test according to Annex 16, paragraph 4.
Vibration test a. System shall not develop amplitudes of vibration in excess of manufacturer’s recommendations.
