Some elements that plugging of fire-arrester, unmatchable rated breathing vs oil loading/unloading and so on result in the sag of tank top.

• 列举了引起油罐负压超限的各种因素,即波纹阻火器的堵塞、呼吸量与进出油量不匹配、油罐附件安装前未做好拆检工作及未按设计要求使用油罐。