调节阀汽蚀和闪蒸的危害及应对方法

Hazards of cavitation and flash of regulating valves and countermeasures

针对成品油站场调节阀发生汽蚀和闪蒸时会对管道设备带来冲击、撕裂、震动与噪音过大、计量不准确等危害,结合调节阀汽蚀和闪蒸的产生机理,分析得出调节阀发生汽蚀和闪蒸的主要影响因素为调节阀结构不合理、安装位置不当、运行工况多变等。由此提出了应对方法:选择低进高出的角式调节阀结构,选用具有防汽蚀功能和材质硬度较高的阀芯,将调节阀安装在站场较低位置并与下游设备保持足够大的距离,安装消气器,在进出口管道配置袖管,避免或减少调节阀在小流量或进出口压差较大的工况下运行等,从而有效避免汽蚀或闪蒸的发生,使调节阀正常运行。

Cavitation and flash of regulating valves in stations along product oil pipelines may impact or break pipeline devices, produce vibrations, noises and other hazards that may negatively affect metering operations. With consideration to mechanisms for generation of cavitation and flash in regulating valves, unreasonable structures, improper installation positions, various working conditions and so on are key factors that may induce cavitation and flash in regulating valves. In addition, proper countermeasures have been proposed： deployment of regulating valves with angular structures with input end at lower position and output end at higher position, adoption of cavitation-resistant valve cores, utilization of materials with higher hardness, installation of regulating valves in lower positions in stations and sufficient distances shall be maintained from downstream devices, installation of getter devices, deployment of sleeves on inlet and outlet pipelines, avoiding or reducing operations of regulating valves under minor flow rates or under significant differential pressures at inlet and outlet other relevant measures. Above-mentioned methods may effectively eliminate the possibility of cavitation and flash to maintain proper functioning of regulating valves.