Background/Objectives: The objective of this paper is to design centralised controller for liquid level in the two interacting conical tank system. Methods/Statistical analysis: Two Centralised Proportional and Integral (PI) controller tuning method (Davison method and Tanttu and Liestehto method) are used for simulation and implemented in real time process. Findings: Centralised PI controller reduces the interaction between the two interacting conical tank and improves the system performance. The performances are compared in terms of Integral Square Error (ISE) and Peak Overshoot. It is observed that Tanttu and Liestehto method produces better response than Davison method. Applications/Improvements: Level control in two interacting conical tank is used in chemical industries and water treatment plants.