Injection Unit 95730967Injection units connect the dosing line with the process line. They ensure a minimum counterpressure of 0. 7 bar, and avoid backflow of the dosing liquid. The spring loaded non return valve comes with Tantal spring. Injection units with lip valve are typically used to add sodium hypochlorite solution to water with a high carbonate content. The FKM lip prevents crystallisation and blocking caused by alkali carbonate reactions at the point of injection.