Comparison of target safety level for onshore pipelines between ISO 16708-2006 and CSA Z662-2007

The International Organization for Standardization (ISO) and the Canadian Standards Association (CSA) have issued reliability-based pipeline design and assessment standards successively. Based on comparative study, both standards are different in the calculation methods of onshore pipeline target safety level. In ISO 16708-2006, the calculation is based on pressure and pipe diameter according to safety levels. In CSA Z662-2007, however, the calculation is based on population density, pressure, and pipe diameter, and the effect of population density is quantified. In order to analyze their difference further, the onshore pipeline target safety levels were quantitatively compared between two standards in reference to the basic data of domestic pipelines. It is shown that CSA Z662-2007 is slightly lower than ISO 16708-2006 in terms of onshore pipeline target safety level, because ISO 16708-2006 is stricter in regional grade division. Finally, some suggestions were proposed for the status that domestic pipelines were lack of rational target safety level.