Seal face can be repaired (Picture Four): This kind of valve has assistant seal system.In case of emergency or the seal is damaged, the assistant seal system can repair the seal face.

• 可修补密封面（见图四）：本阀门设计有辅助的阀座紧急密封系统，一旦密封受损或出现紧急情况而不能密封时，通过辅助密封系统向密封面注射相应的密封剂即可修复密封面，达到紧急密封。