Patent ID: 6752024
Filing Date: 2004-06-22
Classification: F16K,G01L

Abstract:
A system for determining the compressive loading of a packing gland providing a seal around an elongate member inserted through a stuffing box, the packing gland being compressed by a source of applied force, comprising:a load sensor for disposition between the packing gland and the source of applied force comprising: a compressible inner layer having opposed generally flat faces on opposite sides and a central opening, said inner layer formed of dielectric material having a known dielectric constant; an electrically conductive ring on a first one of the faces and surrounding the central opening; an electrically conductive ring on the second, opposite face and surrounding the central opening; a first outer layer of dielectric material having a central opening in registration with the central opening in the inner layer; a second outer layer of dielectric material having a central opening in registration with the central opening in the inner layer; and a pair of conductors coupled to the electrically conductive rings on the faces of the inner layer; and a capacitance measuring instrument connectable to the load sensor conductors and producing a signal indicative of the measured capacitance between the electrically conductive rings as a function of the spacing between the rings; and a display coupled to the capacitance measuring instrument to receive the measured capacitance signal and provide a readout of the compressive loading on the packing gland.