SAPV及API579凹坑评定标准用于尿素合成塔的保守度评价

分别运用SAPV和API579规范对某化肥厂含腐蚀凹坑尿素合成塔上封头进行安全评定，并与有限元极限分析结果和分析设计规范强度校核的结果进行了比较，对SAPV和API579两种凹坑安全评定方法的保守度进行了讨论，作者认为：API579及SAPV的球形封头凹坑安全评定方法均足够保守，SAPV球形封头凹坑评定规程用于外壁凹坑时安全裕度是恰当的，但用于内壁凹坑时显得过分保守，提出了球壳内壁凹坑安全评定时可适当降低安全系数的建议。

Conservative Factor Evaluation of Local Thinning Defect Assessment Standard(SAPV and API579) Using in Urea Reactor

The safety assessment of the urea reactor upper head with corrosion pit in one Chemical Fertilizer Plant was studied by using the codes of SAPV and API579, and the results of the safety assessment were compared with its plastic limit load analysis and its strength check by analysis design code, the conservative factor of SAPV and API579 codes in the safety assessment of the urea reactor was also discussed, some conclusions were gotten and they are: if SAPV and API579 is used for the safety assessment of the urea reactor spherical head with pit, its results are quite conservative, when spherical head with outer pit is assessed by SAPV, the safe factor is suitable, when the safety assessment of the sphere with inner pit is proposed by SAPV, its results is conservative excessively, the safe factor could be advisably reduced.