机械密封运行可靠性与失效分析.pptVIP

机械密封维护 及其运行可靠性;机封运行可靠性由以下因素决定：;密封类型 推进型/波纹管 密封排列形式 单/双封 内/外装 带压/无压 冲洗的形式 冷却/清洗/隔离;泵的类型 悬臂式 双支撑 密封腔体设计 腔体直径 长度 冲洗口连接 轴的设计 直径 挠度;适合于该类型密封;冲洗系统的设计;密封安装;泵的安装;泵的操作;辅助系统及冲洗系统的Operation;密封失效指被密封流体通过密封部件后，泄露量超过所要求值，稀释了工艺介质，或对环境造成毒害，存在直接的危险性。实际上，“失效”的原始含义是由用户、当地及州政府或联邦法律所定义出来的。;密封失效原因;诊断方法;失效模式;System Status 系统状况;Life Cycle History 寿命周期;System and Equipment Checks;;Seal Component Visual Analysis;Comprehensive Examination综合测验;Contact Pattern;Contact Wider Than Width of Primary Ring Face;Eccentric Contact Pattern古怪的;Heavy to Moderate Contact;Light Contact;Full contact through 360?with one visible high spot on mating ring surface. Wear at drive notches on primary ring may also be noted. The mating ring misaligned, often due to a high antirotation pin.;Full contact through approximately 270?as seen on mating ring surface. Pattern fades away at low spot. The primary ring may show wire drawing or wire brushing in a position where the ring lined up with a low spot on the mating ring if the rotor was left idle while under pressure. The mating ring is being distorted mechanically.;Two large contact spots are noted while the pattern fades away between contact areas. The primary ring may show wire drawing or wire brushing in a position where the ring lined up with low spots on the mating ring if the rotor was left idle while under pressure. The mating ring is being distorted mechanically. The split line on axially split pump casings is most suspect.;Contact spots noted at gland stud locations on mating ring. Mating ring is being distorted mechanically by uneven gland surface. Clamping load provided by the gland bolting is distorting the gland. Most often the gland nuts have been overtightened.;Many small radial surface cracks through entire face contact area normally visible to the eye. High wear of one face, typically the carbon face, is likely as it will be ground down by the cracked surface. Squealing, chirping, or popping will often be noted as well before the seal starts to