The joint use of mechanical seal, the sealing element with high temperature resistance, wear resistance, self-lubrication materials. The sealing element abrasion automatic compensation, installation of embedded thread connection, and remember the installation end and a mounting hole processing required more than Ra1.6, to ensure the sealing reliability. Conditions of use: medium: water, coolant pressure: 1.03MPa temperature: 121 ℃ speed: 10r/min