UN R134 — 02 series of amendments

The CHSS definition now names container attachments (if any) and all primary closure devices, instead of pressure relief devices (PRDs) and shut off device(s). New paragraphs 2.5., 2.18., 2.20., 2.25. and 2.26. define “Container Attachments”, “Passenger compartment”, REESS, HRR/A and “State of charge (SOC)”. The SOC definition refers to new Table 1, which lists the compressed hydrogen density (g/l) at different pressures and temperatures. The definitions of “Exhaust point of discharge” and “Safety relief valve” are deleted. In paragraph 2.12., hydrogen fuel for the vehicles is now specified in ISO 14687:2019 and SAE J2719_202003. Footnote 1 to paragraph 1 no longer lists full width frontal impact among the post-crash cases that the Regulation does not cover.

Primary closure devices must include TPRD, check valve and shut-off valve functions (which may be combined) and be mounted directly on or within each container. The minimum burst pressure BPmin is now 200 per cent NWP, instead of 225 per cent NWP. In the baseline initial pressure cycle life test, leakage must not occur within 11,000 cycles; the 15,000-cycle value for a 20-year service life is deleted. The manufacturer now determines the CHSS service life, and the date of removal from service is at most 25 years after the date of manufacture. In the fire test, the CHSS must vent below 1 MPa within 1 hour (M1, N1) or 2 hours (M2, M3, N2, N3). Annex 7 now says that deviations from the reduced test programme table may be allowed if equivalent safety can be ensured.

Annex 3, paragraph 5. now gives the two-stage localized/engulfing fire test: a localized fire stage followed by an engulfing stage. The former fire test methods (Method 1, generic vehicle installation; Method 2, specific vehicle installation) and the former engulfing fire test are deleted. The burner has a localized burner zone and an engulfing burner extension, and both must be LPG-fired. The burner pre-test checkout uses a 320 mm diameter pre-test cylinder. The pre-test must be performed at least once before CHSS fire tests, and repeated if the burner and test setup is modified.

Paragraph 6.1. adds the atmospheric exposure test (Annex 4, paragraph 1.11.) to the TPRD performance requirements. Paragraph 6.2. now covers check valves and shut-off valves, instead of check valves and automatic shut-off valves. The pre-cooled hydrogen exposure test (Annex 4, paragraph 2.10.) is deleted. Five TPRD units now undergo 15,000 internal pressure cycles, instead of 11,000 (15-year service life) or 15,000 (20-year service life). The total number of operational cycles is now 15,000 for the check valve and 50,000 for the shut-off valve, without separate 20-year service life values.

New paragraph 7.1.1.5. requires the fuelling receptacle geometry to conform to ISO 17268:2020 and be compatible with “specification H35, H35HF or H70 depending on its nominal working pressure and specific application”. TPRD hydrogen discharge from the CHSS must also not impinge upon the vehicle’s REESS. For frontal impact, paragraph 7.2. now uses UN Regulation No. 94, Annex 3 and UN Regulation No. 137, Annex 3, “only to the extent where the UN Regulations apply as prescribed in their scope”. The post-crash requirement is deemed met if the vehicle equipped with CHSS is approved to “UN Regulation No. 94 (05 series of amendments or later) or UN Regulation No. 137 (03 series of amendments or later) for frontal impact and UN Regulation No. 95 (06 series of amendments or later) for lateral impact”, as applicable in their scope. Where the frontal or lateral impact test does not apply, the position limits now apply to the CHSS primary closure devices instead of the container. At the request of the manufacturer, the CHSS may be tested to new Annex 8 as alternative to paragraph 7.2.4.2.

Paragraph 9.1. now refers to the general provisions in Schedule 1 to the Agreement (E/ECE/324‑E/ECE/TRANS/505/Rev.3 and amend.1), instead of Appendix 2. The former general provisions of paragraphs 9.1. and 9.2. are deleted. Paragraph 9.2.1. requires a pressure test of every container or, “upon agreement of the Type Approval Authority, every pressure bearing chamber of CHSS”. The target pressure is ≥ 125 per cent NWP, held for ≥ 30 seconds; before, every container was tested at ≥ 150 per cent of NWP. A batch is at most 200 units or one shift of successive production, whichever is greater; at least one random CHSS per batch is tested. “Upon request by the manufacturer after completion of at least 20 sequential batches, including at least 2,000 finished containers, complying with the requirements of paragraph 9.2.2.1.”, the type approval authority may recognise alternative sampling procedures.

As from “the official date of entry into force of the 02 series of amendments”, Contracting Parties applying this Regulation must not refuse to grant or accept approvals under the 02 series of amendments. From 1 September 2027, Contracting Parties applying this Regulation are not obliged to accept approvals to the preceding series first issued after 1 September 2027. Contracting Parties applying this Regulation must continue to accept approvals to any preceding series first issued before 1 September 2027, “provided the transitional provisions in these respective previous series of amendments foresee this possibility”. Contracting Parties applying this Regulation may grant approvals according to any preceding series, and must continue to grant extensions of existing approvals to those series. In Annex 2, the approval mark examples now refer to the 02 series of amendments.