Proposed revisions are identified to allow labs the option to use a pressure vessel for the testing of all automotive gasoline samples, rather than just for highly volatile automotive gasoline samples with vapor pressures 80 kPa as indicated in section 11.3.1 of the method, as a follow-up to an e-mail correspondence request that was discussed at the December 2011 SC5.C meeting with the members and guests in attendance. The justification for the requested change was three-fold: 1.Mitigation of potential safety concerns / exposure issues using a pressure vessel versus a vented test tube when testing gasoline samples, even if the vented test tubes inside the corrosion bath are maintained inside a hood. 2.Use of a pressure vessel prevents excessive evaporation losses that could lead to sample integrity/testing issues (e.g., testing samples in test tubes can result in the copper strip being exposed outside the liquid sample if the sample losses are excessive even if the vapor pressure is 80 kPa). 3.The requesting lab is trying to make the testing protocol consistent throughout the year (i.e., winter and summer gasoline testing seasons) for the lab technicians to use the pressure vessels where the winter gasoline is typically above the 80 kPa vapor pressure caveat limit where the method recommends (i.e., non-mandatory requirement) the use of the pressure vessel versus summer gasoline samples where the vapor pressure is 80 kPa and outside the recommendation for using a pressure vessel. In most cases, lab technicians do not know the vapor pressure of the sample prior to initiating the D130 test, since given the D130 test duration (and need for the lab to turnaround test results as quick as possible to avoid missing product release), samples for D130 analysis are started soon after being received in the lab. As part of the discussion at the December 2012 SC5.C meeting, it was decided to initiate a ballot revision to address this request, as well as to provide additional updates to the method, namely, that section 14.1 be updated to indicate that the gasoline precision statement that was determined was based on samples specifically analyzed by the test tube procedure (i.e., no samples analyzed using a pressure vessel), and secondly, to update the Report section to indicate if a pressure vessel was used when testing automotive gasoline samples to report that information to the data recipients so that it is clear how results were determined.
Keywordsautomotive gasoline; aviation gasoline; aviation turbine fuel; copper corrosion; copper strip; corrosiveness to copper; natural gasoline; Automotive engine fuels/oils; Aviation fuels; Aviation turbine fuels; Copper corrosion; Copper strip tarnish; Corrosion--petroleum products; Gasoline; Strip test ;
Draft Under Development