天然气放空管道选材分析

Analysis on material selection of natural gas vent pipeline

关键词:  放空管道  放空温度  低温  低应力  背压  选材 

Key words:  vent pipeline  vent temperature  low temperature  low stress  back pressure  material selection

摘要:

对高压天然气放空管道的选材进行了研究。天然气管道放空时温度较低,超出了普通碳钢的使用温度下限,需按“低温低应力工况”考虑。通过对某天然气放空管道的操作温度、操作压力及应力进行核算,分析其是否处于“低温低应力工况”。结果 表明,放空管道操作压力低于1.0 MPa,正常操作时的轴向拉应力低于材料标准规定的20#钢最小抗拉强度值的10%,管道操作工况处于“低温低应力工况”,管道材质可以使用20#钢。 

Abstract:

The material selection of high-pressure natural gas vent pipeline was studied. The operating temperature of natural gas vent pipe is low, which exceeds the avowable lower limit temperature of ordinary carbon steel. In this case,low temperature and stress conditions should be considered. By calculating the operation temperature, operation pressure and stress of a natural gas vent pipe,whether it is in the condition of low temperature and low stress is analyzed. The results show that when the vent pipe operating pressure is below 1.0 MPa for normal operation, the axial tensile stress is below 10% of the minimum tensile strength value of steel 20#. Pipeline operation condition is “low temperature and stress condition”. Therefore, 20# steel can be used as natural gas vent pipe.