球罐技术问答1.何为球罐设计压力? ......................................................... 52.何为球罐计算压力? ......................................................... 53.何为球罐试验压力? ......................................................... 54.GB12337-1998 对试验压力最低值有何规定？ .................................... 55.GB12337-1998 对试验压力的上限有...