Chlorine dosing systems working in accordance with DIN 19606 are deployed to disinfect drinking water, especially in large waterworks. These systems use chlorine in cylinders and drums in accordance with the standards of DIN EN 937. The maximum permissible amount of chlorine is 1.2 mg/l, and the usual concentration at the output of the waterworks lies between 0.1 and 0.3 mg/l.
To maintain these values precisely, the dosing of chlorine gas is usually controlled by a volume signal that is monitored by automatic measurement and control technology. The chlorine gas system operates as a full vacuum system, which means that there is negative pressure at the time of withdrawal from the tank to eliminate any risk of chlorine gas escaping in the event of a leakage.
The safety requirements placed on the system, the room and operation make the chlorine gas procedure an extremely safe method of drinking water disinfection. Two or more chlorine gas tanks with automatic switching are normally provided to ensure continuous chlorination. These automatically switch over to a full chlorine gas tank as soon as one of the connected tanks is empty.