Research On The Design Of Unloading Valve Of Offshore Platform

Unloading valve is a valve which installed in the ballast tank of jack-up platform,in the towing process,the valve is used to block the sea water into the ballast tank when in closed state.After the platform arrived at the specified location,the advance ballast operation is needed.The unloading valve needed to be open to drain off the sea water of ballast tank after the advance ballast operation,which will prevent water influencing on normal production operation of platform.The current unloading valve used in offshore oil platform has a poor sealing performance and it can’t completely empty ballast water.The valve stem is also easy to corrode.Therefore we need to design a new kind of discharge valve which has a good seal performance and can drain off the water.It has double control and can prevent the water back into the ballast tank.The discharge valve can improve the safety and reliability of towing operation of the platform and can reduce the hidden danger due to the damage of unloading valve in the process of towing operation.According to research and analysis of offshore unloading valve,the working principle and the existing problems of offshore unloading valve is fully understood.And because of that,we came up with a design of a DN200,PN16 unloading valve for offshore platform.And we put forward to the design scheme of 3D modeling.The related parameters were calculated,which provides a theoretical basis for design.According to the 3D model,the finite element model of offshore unloading valve is established,and the key parts are analyzed by using the Workbench software.The sealing analysis of the bottom disc ring and the lateral disc ring is made too.The fluid simulation analysis of the internal flow field of valve is made by using the cfx module of workbench software.We can obtain the flow chart of the fluid,the velocity vector diagram and the stress distribution.According to the diagram,the parameters related to lateral force components of unloading valve are optimized to improve.The fluid analysis results about the structure of the valve can guide design,which make the unloading valve save the opening and closing time after improvement.Therefore the valve can be quickly open and closed.