Document ID: chunk:federal_register_of_legislation:F2023L01530:body:0:p38
Version: federal_register_of_legislation:F2023L01530
Segment Type: other
Provision Reference: 
Character Range: 108503–111243

Low temperature: condition the unit at -40 °C or lower; test at 5 per cent NWP (+0/-2 MPa) and 100 per cent NWP (+2/-0 MPa).
         Additional units undergo leak testing as specified in other tests in Annex 4, paragraph 1. with uninterrupted exposure at the temperature specified in those tests.
         At all specified test temperatures, the unit is conditioned for one minute by immersion in a temperature controlled fluid (or equivalent method). If no bubbles are observed for the specified time period, the sample passes the test. If bubbles are detected, the leak rate is measured by an appropriate method. The total hydrogen leak rate shall be less than 10 Nml/hr.
         1.9. Bench top activation test
         Two new TPRD units are tested without being subjected to other design qualification tests in order to establish a baseline time for activation. Additional pre-tested units (pre-tested according to Annex 4, paragraphs 1.1., 1.3., 1.4., 1.5. or 1.7.) undergo bench top activation testing as specified in other tests in Annex 4, paragraph 1.
              (a) The test setup consists of either an oven or chimney which is capable of controlling air temperature and flow to achieve 600 (±10) °C in the air surrounding the TPRD. The TPRD unit is not exposed directly to flame. The TPRD unit is mounted in a fixture according to the manufacturer's installation instructions; the test configuration is to be documented;
              (b) A thermocouple is placed in the oven or chimney to monitor the temperature. The temperature remains within the acceptable range for two minutes prior to running the test;
              (c) The pressurized TPRD unit is inserted into the oven or chimney, and the time for the device to activate is recorded. Prior to insertion into the oven or chimney, one new (not pre-tested) TPRD unit is pressurized to no more than 25 per cent NWP (the pre-tested); TPRD units are pressurized to no more than 25 per cent NWP; and one new (not pre-tested) TPRD unit is pressurized to 100 per cent NWP;
              (d) TPRD units previously subjected to other tests in Annex 4, paragraph 1. shall activate within a period no more than two minutes longer than the baseline activation time of the new TPRD unit that was pressurized to up to 25 per cent NWP;
              (e) The difference in the activation time of the two TPRD units that had not undergone previous testing shall be no more than 2 minutes.
         1.10. Flow rate test
              (a) Eight TPRD units are tested for flow capacity. The eight units consist of three new TPRD units and one TPRD unit from each of the following previous tests: Annex 4, paragraphs 1.1., 1.3., 1.4., 1.5. and 1.7. ;
              (b) Each TPRD unit is