Any attachments to the valve would generally fall under the definition of an extended structure/mass and typically consist of items necessary for the valve to perform it's safety-related function (solenoids, pilot operators, switches).
If it’s a required active valve, it’s evaluated to ensure operability after an SSE…if it’s not required to function after an SSE, it’s evaluated to ensure only structural integrity to ensure it does not interact/cause failure of a safety-related component.