This document introduces the overview, product classification, usage conditions, main technical performance, operation and debugging, maintenance, storage, warranty matters, and technical support of the QT series electric actuators. The QT series electric actuators are terminal control devices for industrial process measurement and control systems, suitable for controlling 90° rotating valves such as ball valves, butterfly valves, and plug valves. This product is characterized by small size, light weight, high efficiency, high reliability, high protection performance, low noise, easy installation, debugging, and maintenance. It can be widely used in industries such as petroleum, chemical, power plants, water treatment, and papermaking.