Mining Publication: Evaluation of Safety Shutoff Valve System on Methane Gas Pipelines Under Mine Fire Conditions

• Fires
• Horizontal boreholes
• Methane

The purpose of this investigation was to evaluate the integrity of the existing shutoff valves and actuators used under high-temperature conditions in the Bureau of Mines horizontal borehole methane drainage pipeline system and to determine the potential for improvement in the system. In the field tests, both firesafe ball valves and standard brass ball valves were initially subjected to a 30-min pan fire without thermal protection. Neither valve could maintain line pressure beyond 11 min in a fire that reached temperatures between 500 degrees and 700 degrees C. Based on the test results, it was concluded that the brass ball valve used in the Bureau methane drainage pipeline system can be retrofitted with an inexpensive fire bag to substantially increase its integrity under mine fire conditions.