Continuous tilt angle indicator for a swing or tilting disk check valve

A continuous tilt angle sensing apparatus operable for measuring a tilt angle of a rotating closure element in a valve, the closure element being suspended by a hinge pin fixed to the closure element, the apparatus comprising:

• a housing extension physically cooperative with and sealed to a valve housing the housing extension having an interior within which the hinge pin of the closure element is accessible;
• a hinge pin extension located within the housing extension and mechanically cooperative with the hinge pin of the closure element, such that the hinge pin extension is caused to rotate when the closure element rotates;
• a mechanical converter located within the housing extension, the mechanical converter being cooperative with the hinge pin extension and with a magnet carrier, the mechanical converter being also located within the housing extension and being configured to mechanically convert rotation of the hinge pin extension into translational movement of the magnet carrier within the housing extension;
• a core magnet located within the housing extension and physically cooperative with the magnet carrier;
• and
• a linear variable differential transformer (LVDT) coil set arranged external to the housing extension and located such that the core magnet is translated within the LVDT coil set when the closure element is rotated, the housing extension forming a non-magnetic barrier therebetween,
• the core magnet and LVDT coil set thereby operating together as a linear variable differential transformer that produces an LVDT output signal indicating a tilt angle of the closure element.