Abstract

Ballasting and De-ballasting of water are the key operations in working of a floating dry dock in order to dock and undock a water vessel in the yard. These operations involve pumping of sea water from sea chests to their respective ballast tanks through pumps. Since these ballast tanks are present throughout the dock the filling time for each tank is different. Due to this reason filling of tanks with same water flow rate is not practical and hence all the tanks are filled with different pipes and all the pipes are fitted with individual water valves. These water valves are set as per the required water flow rate for different water ballast tank as per the time taken for the water to reach and fill the respective water ballast tank. This valve setting operation can be enhanced better if Automatic Process Control valves are implemented for the same. Process controlled valves are valves which partially open and close as per the flow of water required according to the amount of water filled in respective ballast tank. A process-controlled valve is used with the help of a PLC system which is used to command the valve to control the flow of the water in ballast tank as per the required flow rate.