Pipe diameter change detection device for small-diameter pipe of boiler

The utility model discloses and provides a boiler small-diameter tube diameter change detection device, which comprises a fixing ring, twelve groups of circular through grooves are formed in the inner wall of the fixing ring, limiting tubes are fixedly mounted on the outer sides of the twelve groups of circular through grooves, a cavity is formed in the inner wall of each limiting tube, a telescopic rod is movably mounted in each cavity, and the limiting tubes are fixedly mounted on the inner wall of the fixing ring. One end of the telescopic rod is in an arc shape, one end of the telescopic rod is connected with four groups of detection clamps, the outer surface of each detection clamp is connected with a spring, and one end of each spring is connected with a fixing ring. And the four groups of detection clamps can stretch out and draw back under the action of the springs, so that in the process of detecting the small-diameter tube, if an uneven place is found, the detection clamps can move to remind people