Analysis on the Low-temperature and Low-stress Conditions for Pressurized Tank of Natural Gas

An analysis is made on the influence of low temperature environment on the property of natural gas spherical tank used in the frigid region. The results show that the ductile status of steel material for spherical tank will transit to brittle status at low temperature condition, and if the operating pressure goes beyond the specified limitation, the low-temperature brittle fracture will happen. So, selecting a proper design temperature and pressure will be beneficial to the cost of pressure vessel and its safe operation. Taking a 2000 m³ natural gas spherical tank as an example, the paper introduces how to select the design temperature of spherical tank and the control method for low-temperature and low-stress conditions.