Orbinox UK Ltd This 20″ #150 high performance butterfly valve is fitted with a BETTIS™ ‘G’ series single acting pneumatic actuator c/w DVC6200S positioner, and incorporates a closed loop breather system. Its application is the mast riser valve on an FSO and is used during the crude oil loading for tank vapour pressure control. The rate of displacement of VOC vapours from the cargo tank system will be the same as the crude oil loading rate but the concentration of VOC vapours in the displaced stream will be greater dependent upon the extent and rate of evolution of VOC vapours from the incoming cargo that would add to the volume of gas/vapour mixture already existent prior to loading.
