Rationale for the proposal to harmonize UN R110 with ISO 11439:2013.

Comments from NGV Global on the proposals from Italy (GRSG-112-28) and Germany (GRSG-112-33) regarding the testing and inspection of CNG cylinders.

In the absence of complete harmonization with ISO 11439, this proposal recommends that Table 6.4 of UN R110 should be amended by the following for CNG-1 designs:

1. Delete A.17, A.25, and A.7 since they do not match the tests specified in paragraph 7.5 on Cylinder design qualification tests
2. Add A.15 and A.6 since they do match the tests specified in paragraph 7.5 on Cylinder design qualification tests
3. Add A.24 because paragraph 6.9 on Fire protection requires all PRDs on all cylinder types to comply with A.24.

Proposal to improve provisions for the visual inspection of CNG cylinders, LNG tanks, and their accessories. Germany has proposed (document GRSG-112-33) the prohibition of components or parts of protective housing which must be disassembled during inspection. Italy has proposed (document GRSG-112-28) that visual inspection of cylinders Include access inside any protective covers of the cylinders. Based upon field experience, OICA believes that corrosion damage between support straps, brackets, and pads and the cylinder can be readily identified during visual inspection. Such corrosion requires cylinder replacement. Therefore, OICA proposes clarifications to inspection procedures to address the German and Italian concerns.

Proposal to include transitional provisions for the alignment of UN Regulation No. 110 with ISO 11439:2013 per document GRSG/2017/31.

Proposal for further discussion concerning technical advances in the use of CNG accumulators as an intermediate technology for promoting high, stable pressure in CNG engine injection systems. The CNG accumulator is used to stabilize the gas pressure and to allow engine operation whenever the LNG supply system is not able to deliver fuel. This proposal would define requirements to enable the certification of these components.

Proposal for discussion to enable the certification of CNG compressor components. Due to density and temperature constraints, LNG fuel systems require technologies to warm the LNG fuel to reach temperatures and pressures suitable for the engine. In some configurations, this involves the use of CNG compressors. Therefore, this proposal seeks to enable use of this technology through establishment of requirements to ensure safety.

Proposal to clarify the test procedure to be applied in assessing compliance with the requirement for “compatibility with heat exchange fluids of non-metallic parts” Annex 5Q is part of UN Regulation No. 110. In Annex 4D, the wording “Compatibility with heat exchange fluids” is used but there is no reference to the applicable tests. The proposal clarifies that the “LNG heat exchanger – vaporizer” falls within Annex 5Q. The proposal correspondingly clarifies the general overview Figure 1-2, with all tests from Annex 5, and Table 5.1 in Annex 5.

Proposal to harmonize the requirements for CNG/LNG vehicles under UN R110 with those of the international standard ISO 11439:2013.

Proposal to harmonize the requirements for CNG/LNG vehicles under UN R110 with those of the international standard ISO 11439:2013.