Abstract: The test standards for the watertightness of shield tail sealing grease under high water pressure are not uniform around the world, and the performance of the sealing grease cannot be quantitatively tested. Therefore, in this study, a new method of testing the sealing performance of shield tail sealing grease under high water pressure is developed, and watertightness tests are conducted on commonly used types of shield tail sealing grease. Following an analysis, the sealing mechanism for sealing grease under highpressure conditions is summarized, and test standards for the water breakdown pressure are defined. The water breakdown pressure is the minimum water pressure that will puncture 300 g of shield tail sealing grease on a layer of metal wire mesh that has a mesh hole diameter of 0.76 mm and a steel wire diameter of 0.3 mm at 25 ℃. The water breakdown pressure can be used to quantitatively evaluate the sealing performance of shield tail sealing grease under water pressure. Finally, the test standards are proposed.

Key words:  , shield tail sealing grease, testing device for watertightness under high pressure, watertightness under high pressure, evaluation standards, water breakdown pressure