Mechanical seal is a seal device for rotating machinery. Such as centrifugal pumps, centrifuges, reactors and compressors and other equipment. Since the drive shaft through between the inner and outer equipment, mechanical seals, so that the mechanical seal positioning axis there is a circumferential gap with the device, the device media leak out through the gap, if lower than the atmospheric pressure inside the equipment, mining machinery seal, the air is leaking into the device first to know life index is calculated based on the comprehensive factors selected materials, processing methods and expected conditions of use and other values. due to material defects, processing and use of uncertainties, and should not Each life assurance mechanical seals reach consensus.