Proposal to introduce a change of definition of working pressure for LNG, and introduce a value for that pressure in Annex 3B. Proposal also applicable for Supplement 2 to the 05 series of Amendments

39. Moreover, GRSG considered GRSG-123-24 to introduce a change of definition of working pressure for LNG, and to introduce a value for that pressure in annex 3B. GRSG finally agreed to resume discussion at its October 2022 session on a new official proposal drafted by a Task Force coordinated by the expert of NGVA Europe.

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.

Proposal e to introduce a missing transitional provision to 04 series to cover the acceptance of type approvals according to the preceding series when not affected by the provisions of the new series.

21. GRSG considered GRSG-124-32, tabled by NGVA Europe to accept the type approvals according to the preceding series when not affected by the provisions of the new series of amendments. GRSG acknowledged the need to be consistent throughout all the series of amendments to the UN Regulation, and adopted GRSG-124-32 as reproduced in annex II to the session report. The secretariat was requested to submit the proposal as draft Supplement 4 to the 04 series of amendments to UN Regulation No. 110, for consideration and vote at the June 2023 sessions of WP.29 and AC.1. At the same time, it was agreed to keep the official proposal to WP.29 in the agenda of the March 2023 session of GRSG for possible further development.