Document ID: chunk:federal_register_of_legislation:F2023L01530:body:0:p29
Version: federal_register_of_legislation:F2023L01530
Segment Type: other
Provision Reference: 
Character Range: 82580–85512

to the specified target pressures according to paragraph 2.2. of this Annex at 20 (±5) °C for the specified numbers of cycles. The glass wool pads are removed and the container surface is rinsed with water the final 10 cycles to specified final target pressure are conducted.
         3.5. Static pressure test (hydraulic)
         The storage system is pressurized to the target pressure in a temperature-controlled chamber. The temperature of the chamber and the non-corrosive fuelling fluid is held at the target temperature within ±5 °C for the specified duration.

         4. Test procedures for expected on-road performance (paragraph 5.3. of this Regulation)
         (Pneumatic test procedures are provided; hydraulic test elements are described in Annex 3, paragraph 2.1.)
         4.1. Gas pressure cycling test (pneumatic)
         At the onset of testing, the storage system is stabilized at the specified temperature, relative humidity and fuel level for at least 24 hours. The specified temperature and relative humidity is maintained within the test environment throughout the remainder of the test. (When required in the test specification, the system temperature is stabilized at the external environmental temperature between pressure cycles.) The storage system is pressure cycled between less than 2 (+0/-1) MPa and the specified maximum pressure (±1 MPa). If system controls that are active in vehicle service prevent the pressure from dropping below a specified pressure, the test cycles shall not go below that specified pressure. The fill rate is controlled to a constant 3-minute pressure ramp rate, but with the fuel flow not to exceed 60 g/sec; the temperature of the hydrogen fuel dispensed to the container is controlled to the specified temperature. However, the pressure ramp rate should be decreased if the gas temperature in the container exceeds +85 °C. The defuelling rate is controlled to greater than or equal to the intended vehicle's maximum fuel-demand rate. The specified number of pressure cycles is conducted. If devices and/or controls are used in the intended vehicle application to prevent an extreme internal temperature, the test may be conducted with these devices and/or controls (or equivalent measures).
         4.2. Gas permeation test (pneumatic)
         A storage system is fully filled with hydrogen gas at 115 per cent NWP (+2/-0 MPa) (full fill density equivalent to 100 per cent NWP at +15 °C is 113 per cent NWP at +55 °C) and held at  +55 °C in a sealed container until steady-state permeation or 30 hours, whichever is longer. The total steady-state discharge rate due to leakage and permeation from the storage system is measured.
         4.3. Localized gas leak test (pneumatic)
         A bubble test may be used to fulfil this requirement. The following procedure is used when conducting the bubble test:
              (a) The exhaust of the shut-off valve (and