SENTINEL Injection Quills are designed to safely and efficiently disperse chemicals into process pipelines. Chemicals are injected directly and evenly into the center of the process flow away from the pipe wall and where flow velocity is highest. This direct injection into the center of the flow avoids chemical contact with pipe walls and ensures more even mixing with the process fluid. The integral spring-loaded check disk prevents backflow of pressurized process fluid into the chemical feed when the pump is off or the chemical feed is disconnected.