Patent ID: 7596428

Claim:
A method for monitoring valve assemblies, comprising: measuring vibration characteristics of at least one valve assembly prior to operation; monitoring behavior of said at least one valve assembly during operation, wherein said monitoring behavior comprises: (a) measuring vibration frequencies of said at least one valve assembly, (b) measuring vibration amplitudes of said at least one valve assembly, (c) measuring at least one of: a valve lift of said at least one valve assembly, steam pressures, steam temperatures, displacement, strain, or acceleration, and (d) storing in a memory said monitored behavior, including a duration over which said measurements are taken; comparing said behavior of said at least one valve assembly during operation to said vibration characteristics of said at least one valve assembly; estimating stress levels experienced by said at least one valve assembly during operation based on the comparison of said behavior during operation to said vibration characteristics prior to operation; wherein each of the comparing and estimating operations are performed by at least one of: at least one control unit or at least one characteristic analyzer.