Device and method for quantifying a leakage flow on an actuator

摘要

In a method or device for quantifying a leakage flow on a process control valve, an intact reference control valve is used to determine several reference flow values in advance by placing the reference control valve in several reference opening positions and measuring the respective reference flow value for each of the reference opening positions. When determining the respective reference flow value, a reference mechanical vibration acquired in an environment of the reference control valve is allocated to the respective reference flow value. An instantaneous mechanical vibration is determined on the process control valve when it is closed. The reference mechanical vibration coming closest to the determined instantaneous mechanical vibration is identified by an identity or approximation comparison. The leakage flow is equated with the reference flow value allocated to the identified reference mechanical vibration.

主权项

1. A method for quantifying a wear-induced leakage flow on a closed process control valve that restricts a process stream, comprising the steps of:
using said process control valve when it is intact and does not yet have a wear-induced leakage as a reference control valve or another process control valve of a same design as said process control valve which does not have wear-induced leakage as said reference control valve to determine several reference flow values in advance by placing the reference control valve in several reference opening positions, and measuring the respective reference flow value for each of the reference opening positions; when determining each of the respective reference flow values, allocating a respective reference mechanical vibration acquired in an environment of the reference control valve to each of the respective reference flow values; determining an instantaneous mechanical vibration caused by said wear-induced leakage flow on said closed process control; determining an instantaneous stream force prevailing on said process control valve; identifying one of the respective reference mechanical vibrations coming closest to the determined instantaneous mechanical vibration by way of an identity comparison or approximation comparison; defining said identity comparison or approximation based on the determined instantaneous stream force; and equating the wear-induced leakage flow to be quantified with the respective reference flow value allocated to the one identified reference mechanical vibration.