Assessing Potential Impacts of Releases from Highly Volatile Liquid (HVL) Pipelines

Operators of pipelines carrying highly volatile liquid (HVL) or similar products (e.g. natural gas liquids, propane, butane, etc.) need to understand the potential impacts from release incidents. This consequence analysis contributes to meeting the requirements of the US DOT Pipeline and Hazardous Materials Safety Administration’s (PHMSA) hazardous liquids pipeline transportation regulations (49 CFR § 195) or other similar regulations. The outputs from this analysis, the geographic areas where impacts may occur, can be used to identify where impacts to high consequence areas (HCA) are possible. More generally, this analysis can support better decision-making about risk and mitigation. HVL products, while transported as liquids (under pressure or at regulated temperatures), can be released as vapor and/or liquid depending on the composition of the product.