1. An apparatus for estimation of state of mechanical health of a mechanical element, comprising: a probabilistic data signal processor embedded in a computer, said probabilistic data signal processor comprising: a dynamic state-space model comprising: a process model; and an observation model; a probabilistic updater configured to generate a posterior probability distribution function using both: (1) a prior probability distribution function output from said dynamic state-space model and (2) readings from a load sensor, wherein the mechanical element comprises a valve bearing of a valve, said valve comprising a pipe fitting configured to regulate flow of a substance through a pipe, said load sensor configured to provide time dependent measurements related to load on the valve bearing of the valve; and a probabilistic sample module configured to operate on said posterior probability distribution function to generate an output in the form of at least one probability of state of health of said valve.