PRESSURE RELIEF VALVE (IMAGE) Southwest Research Institute Caption In this image, liquid nitrogen is expelled through a pressure relief valve as part of an SwRI-conducted test to determine their viability for liquid natural gas tanks in the event of a train derailment. The Institute contributed to a Federal Rail Administration report that shows that a study conducted by SwRI demonstrated that the pressure relief valves work as designed to prevent overpressurization and explosion if a derailment occurs. Credit Southwest Research Institute Usage Restrictions Images/Videos may be used by the public for educational and informational purposes only. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.