Abstract: Systems, apparatus, and program code, and methods for monitoring the health and other conditions of the valve, are provided. An exemplary system for monitoring the condition of the gate valve includes a logic module configured to perform the operations of receiving sensor data providing an acoustic emission, vibration, and/or stream level signature and determining the level of lubricity, level of friction, level of surface degradation, and leakage rate at a gate-valve seat interface. An exemplary method for monitoring the condition of the gate valve includes receiving sensor data providing an acoustic emission, vibration, and/or stream level signature and determining the level of lubricity, level of friction, level of surface degradation, and leakage rate at a gate-valve seat interface.