Proposal defines the working pressure for an LNG tank to be the primary relief valve setting (paragraph 4.4.), without stating a minimum value of the said relief valve. If a vehicle has an on-board tank with a primary relief valve that opens at a lower pressure than that at which the filling station is set to stop, the primary relief valve will open during refueling and this is an obvious safety risk.
20. GRSG considered documents prepared by the Task Force on UN Regulation No 110: (a) ECE/TRANS/WP.29/GRSG/2022/23 that introduces the minimum opening set pressure of the primary Liquid Natural Gas (LNG) relief valve, (b) ECE/TRANS/WP.29/GRSG/2022/24 and (c) ECE/TRANS/WP.29/GRSG/2022/25 that updates the existing requirements for CNG/LNG fuelled components. The expert from OICA proposed that the three documents be combined together as a new series of amendments. Therefore, he introduced GRSG-124-31-Rev.1, consolidating the three proposals and amending ECE/TRANS/WP.29/GRSG/2022/24. GRSG adopted ECE/TRANS/WP.29/GRSG/2022/23, ECE/TRANS/WP.29/GRSG/2022/24 and ECE/TRANS/WP.29/GRSG/2022/25 as amended by annex II to the session report. The secretariat was requested to submit the combined document of the three proposals as the 06 series of amendments to UN Regulation No. 110 for consideration and vote at the March 2023 sessions of AC.1 and WP.29.
| GRSG-124-31/Rev.1 | |
| WP.29/2023/24 |