Position Repeatability Test for Knife Gate Valves with Electro Pneumatic Positioners

Repeatability is an important characteristic of the measurement of faithfulness of the response of a system over a period of time. Be it mechanical or electronic equipment, over a certain period of time, there is a certain amount of hysteresis that sets in which renders the system incapable of carrying out its operation with the necessary precision. In applications that employ Knife Gate Valves to control the flow of lesser demanding solid particulate media like powders and fine mixtures, it is necessary that the positioners mounted on the valves display repeatability at all values of opening in every operating cycle. At least during the serviceable life of the valve, it is imperative of the positioner to ensure that hysteresis is not set in and that the internal mechanism is capable of yielding precise results. This paper shall consider four positioners mounted to Knife Gate Valves and subject the same to a repeatability test wherein the valves will be opened to a predetermined opening percentage for two cycles. The current input readings corresponding to these percentage openings shall be noted and graphs shall be plot to understand the repeatability behaviour. The mean values of current input readings for the four positioners shall be plot to determine the reproducibility of the experiment. A conclusion shall be drawn thereafter considering the experimental observations. Gourav Vivek Kulkarni "Position Repeatability Test for Knife Gate Valves with Electro Pneumatic Positioners" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-6 , October 2020, URL: https://www.ijtsrd.com/papers/ijtsrd33572.pdf Paper Url: https://www.ijtsrd.com/engineering/mechanical-engineering/33572/position-repeatability-test-for-knife-gate-valves-with-electro-pneumatic-positioners/gourav-vivek-kulkarni