It has the advantages of fast installation, simple, safe, reliable, not limited by the installation site, convenient for the maintenance of pipes and valves, vibration isolation and sound insulation within a certain angle range, overcoming the deviation caused by the connection of different shafts, and solving the thermal expansion and cold contraction caused by temperature difference. It is widely used in the water supply and drainage of pipeline conveying fluid, and the pipeline engineering of fire protection, air conditioning, gas, petroleum, chemical industry, water treatment, municipal administration, shipbuilding and other pipeline engineering is used to control fluid.