Paguld single-line injector is a plunger lubricator/valve block that supplies a fixed amount of grease each time. The lubrication interval is set by pressure, and long-distance lubrication is realized. A major feature of the single-line lubricator is that each lubricator is independent of each other. The latter outlet does not have to wait for the previous outlet to discharge the oil before it is discharged. This makes the single-line system easy to visually monitor, maintain and replace.