39. The expert from Germany introduced ECE/TRANS/WP.29/GRSG/2017/17 to improve the specifications for the installation and inspection of Compressed Natural Gas (CNG) cylinders or of Liquefied Natural Gas (LNG) tanks and their accessories. GRSG welcomed the proposal and noted that WP.29 and the Administrative Committee of the 1997 Agreement were expected to consider and adopt ECE/TRANS/WP.29/2017/134 on a new UN Rule on Periodical Technical Inspections of motor vehicles using CNG and/or LNG in their propulsion system. The proposal from Germany received a number of comments, especially on the need to align the recommendations for the periodical technical inspections of such vehicles with the specifications for the re-qualification of the CNG cylinders or LNG tanks. GRSG noted the comments received by the experts from NGV Global (GRSG-113-03) and OICA (GRSG-113-20).

40. The expert from Italy proposed to amend in Annex 3A of the Regulation the test requirements for the periodic requalification of CNG cylinders to avoid structural failures during their service life (ECE/TRANS/WP.29/GRSG/2017/29). The expert from the Netherlands raised his concern on the access by inspection centres to detailed provisions for the inspection of such cylinders. Thus, he underlined the need that cylinder manufacturers should make available cylinder inspection manuals. GRSG welcomed the offer by Germany to take the lead of a Task Force to review ECE/TRANS/WP.29/GRSG/2017/17 and ECE/TRANS/WP.29/GRSG/2017/29. It was agreed to also involve the International Motor Vehicle Inspection Committee (CITA) in the discussion and to resume consideration of this subject at its next GRSG session in April 2018.