Document ID: chunk:federal_register_of_legislation:F2023L01530:body:0:p35
Version: federal_register_of_legislation:F2023L01530
Segment Type: other
Provision Reference: 
Character Range: 100874–103561

Bench top activation test (Annex 4 paragraph 1.9.).
         1.2. Accelerated life test.
         Eight TPRD units undergo testing; three at the manufacturer's specified activation temperature, Tact, and five at an accelerated life temperature, Tlife = 9.1 x Tact0.503. The TPRD is placed in an oven or liquid bath with the temperature held constant (±1 °C). The hydrogen gas pressure on the TPRD inlet is 125 per cent NWP (±1 MPa). The pressure supply may be located outside the controlled temperature oven or bath. Each device is pressured individually or through a manifold system. If a manifold system is used, each pressure connection includes a check valve to prevent pressure depletion of the system when one specimen fails. The three TPRDs tested at Tact shall activate in less than ten hours. The five TPRDs tested at Tlife shall not activate in less than 500 hours.
         1.3. Temperature cycling test
              (a) An unpressurized TPRD is placed in a liquid bath maintained at -40 C or lower at least two hours. The TPRD is transferred to a liquid bath maintained at +85 °C or higher within five minutes, and maintained at that temperature at least two hours. The TPRD is transferred to a liquid bath maintained at -40 °C or lower within five minutes;
              (b) Step (a) is repeated until 15 thermal cycles have been achieved;
              (c) With the TPRD conditioned for a minimum of two hours in the -40 °C or lower liquid bath, the internal pressure of the TPRD is cycled with hydrogen gas between 2 MPa (+1/-0 MPa) and 80 per cent NWP (+2/-0 MPa) for 100 cycles while the liquid bath is maintained at -40 °C or lower;
              (d) Following the thermal and pressure cycling, the pressure relief device shall comply with the requirements of Leak test (Annex 4, paragraph 1.8.), except that the Leak test shall be conducted at -40 °C (+5/-0 °C). After the Leak test, the TPRD shall comply with the requirements of Bench top activation test (Annex 4, paragraph 1.9.) and then Flow rate test (Annex 4, paragraph 1.10.).
         1.4. Salt corrosion resistance test
         Two TPRD units are tested. Any non-permanent outlet caps are removed. Each TPRD unit is installed in a test fixture in accordance with the manufacturer's recommended procedure so that external exposure is consistent with realistic installation. Each unit is exposed for 500 hours to a salt spray (fog) test as specified in ASTM B117 (Standard Practice for Operating Salt Spray (Fog) Apparatus) except that in the test of one unit, the pH of the salt solution shall be adjusted to 4.0 ± 0.2 by the addition of sulphuric acid and nitric acid in a 2:1 ratio, and in the test of the