Pressure pipeline blockage self-alarm device for sand-blasting machine

The utility model relates to a pressure pipeline blockage self-alarm device for a sand-blasting machine. The sand-blasting machine comprises a sand-adjusting valve, a spray gun and a pressure pipeline through which the sand-adjusting valve and the spray gun are connected, wherein the pressure pipeline is a shot-blasting rubber tube; the alarm device comprises a bypass thin tube; the bypass thin tube is connected to the root of the shot-blasting rubber tube; at least four hollow plastic balls are mounted in the bypass thin tube; a pipe orifice of the bypass thin tube stretches into water in an open water container; the inner diameter of the bypass thin tube is 1/5-1/3 of the shot-blasting rubber tube; the root of the shot-blasting rubber tube is a connecting part of the shot-blasting rubber tube and the sand-adjusting valve. After the device is blocked by the shot-blasting rubber tube, the pressure between the blockage pint of the shot-blasting rubber tube and the sand-adjusting valve is increased, the internal resistance of the shot-blasting rubber tube is increased, most gas enters the bypass thin tube, the hollow plastic balls in the bypass thin tube overcome the resistance of water to completely or mostly enter into the water of the water container under the thrust of high-pressure gas, and whether the shot-blasting rubber tube is blocked can be known by observing whether the balls are in the water container, so that an alarm function is realized, and then regular work of the device is guaranteed.