Sodium Hypochlorite Batch System is designed to produce 1000-gallon batches of sodium hypochlorite. The basic principle of operation is to put water into the recycle tank and add 50% caustic until the strength of the caustic is approximately 6.75% (typical). Within a few batches, the amount of water and amount of caustic to be added will be established and then lines may be drawn on the tank to show the operators how much water, and then caustic, to add. The 50% caustic can be pumped into the tank or pulled into the system from the shipping container or a storage tank by partially closing the recycle tank outlet valve and opening the 50% caustic tank storage valve. After the caustic is mixed, chlorine is added to the solution to react with the caustic, except for a small amount of excess (0.2% by weight typical). The final excess caustic endpoint is controlled by the batch controller. Sodium hypochlorite strength can be varied by changing the strength of the diluted caustic.