For many years, the safety prescriptions of CNG components and systems installed in natural gas vehicles have been contained in UNECE Regulation 110, with the European Union being one of the 48 parties signing the 1958 Agreement that governs it. This has made possible that approvals granted for either CNG components or vehicles according to UNECE R110 could be mutually recognized within the EU, fostering the widespread use of vehicles using CNG.
It has not been until November 2013 that this text has been amended and approved in order to include LNG in its scope. This process has been carried out by the Task Force on Liquefied Natural Gas vehicles (TF-LNG), a dedicated group of industry experts that prepared all the necessary amendments. This group has counted with the direct participation of major European and North-American LNG component and vehicle manufacturers, as well as with the direct support of NGVA Europe and NGV Global as co-secretariats.
In addition to the safety requirements for the on-board LNG system (storage tanks, vaporizers, pressure regulator, valves, fuel lines, fittings, etc.) the text also includes a requirement for the LNG storage tank on minimum holding time (time without venting) of 5 days after having been filled net full and at the highest point in the design filling temperature/pressure range. R.110 is seen as a benchmark regulation for the global NGV community governing the testing and safety of NGV components, including retrofit and factory-built vehicles.
Source: UNECE, NGVA Europe.