Pressure cycling test. Five TPRD units undergo 11,000 internal pressure cycles with hydrogen gas having gas quality compliant with ISO 14687-2/SAE J2719. The first five pressure cycles are between 2 (±1) MPa and 150 per cent NWP (±1 MPa); the remaining cycles are between 2 (±1) MPa and 125 per cent NWP (±1 MPa). The first 1,500 pressure cycles are conducted at a TPRD temperature of 85 °C or higher. The remaining cycles are conducted at a TPRD temperature of 55 (±5) °C. The maximum pressure cycling rate is ten cycles per minute. Following this test, the pressure relief device shall comply the requirements of Leak test (Annex 4, paragraph 1.8.), Flow rate test (Annex 4, paragraph 1.10.) and Bench top activation test (Annex 4 paragraph 1.9.).
Pressure cycling test. Five TPRD units undergo 11,000 internal pressure cycles with hydrogen gas. The first five pressure cycles are between 2 (±1) MPa and 150% of NWP (±1 MPa); the remaining cycles are between 2 (±1) MPa and 125% of NWP (±1MPa). The first 1500 pressure cycles are conducted at a TPRD temperature of 85 °C or higher. The remaining cycles are conducted at a TPRD temperature of 55 (±5) °C. The maximum pressure cycling rate is 10 cycles per minute. Following this test, the pressure relief device shall comply with the requirements of the Leak test, Flow rate test and the Bench top activation test.
Pressure cycling test. Five TPRD units undergo15,000 internal pressure cycles according to Table 1. Following this test, the pressure relief device shall comply with the requirements of the leak test (Annex 4, paragraph 1.8.), the bench top activation test (Annex 4, paragraph 1.9.) and flow rate test (Annex 4, paragraph 1.10.). See Table 1 below for a summary of the pressure cycles. Table 1 Pressure cycling conditions Pressure cycles to per cent NWP No. of cycles Sample temperature for cycling ≤ 2 MPa to ≥ 150 per cent NWP First 10 ≥ 85 °C ≤ 2 MPa to ≥ 125 per cent NWP Next 2, 240 ≥ 85 °C ≤ 2 MPa to ≥ 125 per cent NWP Next 10,000 20 °C ≤ 2 MPa to ≥ 80 per cent NWP Next 2,750 ≤ -40 °C Note: All cycles are conducted at a rate of ≤ 10 cycles per minute.
