In the Flange Analysis inputs window when doing a Div 1 flange analysis for a ring joint gasket it asks for a nubbin width, what exactly is it asking for? I don't think there is any nubbin in a ring joint flange connection.
Thank you for your question. Both the gasket width [N] and nubbin width [w] are used to determine the contact diameter between the flange face and gasket. In the case of configuration (6), which I believe is the configuration of the ring joint gasket, you will be required to enter the width of the gasket, as shown in Div 1 table 2-5.2, or on the sketch in the Flange Check dialog (click the Show Sketch checkbox in the upper left).