Scoping Study on the Safety Impact of Valve Spacing in Natural Gas Pipelines

The U.S. Department of Transportation's Pipeline and Hazardous Materials Safety Administration (PHMSA) is responsible for ensuring the safe, reliable, and environmentally sound operation of the nation's natural gas and hazardous liquid pipelines. Regulations adopted by PHMSA for gas pipelines are provided in 49 CFR 192, and spacing requirements for valves in gas transmission pipelines are presented in 49 CFR 192.179. The present report describes the findings of a scoping study conducted by Oak Ridge National Laboratory (ORNL) to assist PHMSA in assessing the safety impact of system valve spacing. Calculations of the pressures, temperatures, and flow velocities during a set of representative pipe depressurization transients were carried out using a one-dimensional numerical model with either ideal gas or real gas properties for the fluid. With both ideal gas and real gas properties, the high-consequence area radius for any resulting fire as defined by Stevens in GRI-00/0189 was evaluated as one measure of the pipeline safety. In the real gas case, a model for convective heat transfer from the pipe wall is included to assess the potential for shut-off valve failures due to excessively low temperatures resulting from depressurization cooling of the pipe.

• Corporate Authors:

  Oak Ridge National Laboratory

  Department of Energy
  Oak Ridge, TN  United States  37831

  Department of Energy

  1000 Independence Avenue, SW
  Washington, DC  United States  20585
• Authors:
  • Sulfredge, C D
• Publication Date: 2007

Language

• English

Media Info

• Media Type: Print
• Pagination: 213p

Subject/Index Terms

• TRT Terms: Hazardous materials; Heat transfer; Natural gas; Natural gas pipelines; Pipeline safety; Pressurization; Probability; Regulations
• Subject Areas: Data and Information Technology; Law; Pipelines; Safety and Human Factors;

Filing Info

• Accession Number: 01115090
• Record Type: Publication
• Report/Paper Numbers: ORNL-TM-2006-579
• Contract Numbers: DE-AC05-00OR22725
• Files: TRIS
• Created Date: Nov 25 2008 7:31AM