Consider a scenario where we are heating a liquid partially filled, in a closed vessel. Assume that we are supplying the thermal energy at a constant rate (which is quite high enough) to the vessel and that the vessel loses minimal heat to surrounding. Then does the rate at which pressure builds up within the vessel remain constant or will it change with time.
Note: There isn't heat being directly transferred to the gases above the liquid surface within the container, from the heat source at any point of time.
I hope I haven't missed any Caveats to answer the question properly.