PHMSA -2011-0028

Title: Pipeline Safety: Dangers of Abnormal Snow and Ice Build-Up on Gas Distribution Systems

Summary:  This advisory bulletin advises owners and operators of petroleum gas and natural gas facilities of the need to take the appropriate steps to prevent damage to pipeline facilities from accumulated snow or ice. Past events on natural gas distribution system facilities appear to have been related to either the stress of snow and ice or the malfunction of pressure control equipment due to ice blockage of pressure control equipment vents. This advisory reminds owners and operators of the need to take precautionary actions to prevent adverse events.