Manual control via SCADA - It means the operator must have the option to control the valve manually from the graphics.
3 phase ways - If it is a motor operated valve then they may be talking about the power requirement to the valve. 1 phase or 3 phase as per the valve power ratings.
MCB rating - MCB will be selected as per the valve power rating.
Please check the design document or control philosophy for more details. (or any relevant document)
Some of these details are not clearly described.