油罐内浮盘密封失效原因与预防措施

Seal failure causes and prevention measures of inner floating deck of oil tank

针对油罐内浮盘密封失效问题逐渐凸显的现状,分析了内浮盘静、动密封与油气空间的关系,总结了油罐内浮盘密封失效的主要表现,静密封失效包括:内浮盘盖板搭接面间出现缝隙孔洞,密封胶囊或舌形密封带与内浮盘外边缘间的挟紧部位出现缝隙,防旋导管与内浮盘盖板间不密封,浮盘自动通气孔、人孔与盖板间不密封;动密封失效包括:密封胶囊或舌形密封带与罐内壁间密封性能差,量油导管与量油导管护筒盖间的密封性能差,浮盘人孔盖与人孔座间的密封性能差,防旋转钢丝绳松紧度不满足浮盘安全运行要求。基于设计、施工、使用、检修4个环节分析归纳了内浮盘密封失效的原因,提出了优化设计、控制施工质量、控制内浮盘制造安装质量、内浮盘定期检测与管理、规范检修作业等预防措施。

An investigation on the seal of inner floating deck of oil tank revealed that failures in static seal and dynamic seal often occurred on their post. The former included the gap or hole appearance at overlapping parts of cover plate of inner floating deck,gap appearance at compact parts between the edge of inner floating deck and seal capsule or tongue-shaped seal,seal failure between anti-rotation duct and cover plate of inner floating deck and seal failure among automatic air vent,manhole and cover plate. The latter included the poor performance of the seal among seal capsule,tongue-shaped seal and inner shell of tank,poor performance of the seal between measuring duct and its protecting barrel cover,poor performance of the seal between manhole cover and base and tightness of anti-rotation steel rope not being in accord with the demand of safety operation. Based on causes analysis of seal failure of inner floating deck in design,construction,operation and maintenance,prevention measures are given about optimum design,quality control of construction,manufacture and installation of inner floating deck,regular detection and management of inner floating deck and standardized maintenance operation.