Analysis and countermeasures of mechanical seal failure of high temperature water pump
Electric Vehicle Battery Mold Vac,Electric Vehicle Battery Molding,Electric Vehicle Battery Molds,Electric Vehicle Battery Mold Pad Kunshan Wangdaxin Precision Mould Co., Ltd. , https://www.wdxmould.com
For high temperature hot water pump, hot water circulation pump failure analysis (1) moving ring sealing surface wear serious, may be the end surface pressure Pc is too large, so that the PcV value exceeds the allowable [PcV] value, the mechanical seal structure is constant and the sealing medium Under the condition of constant pressure, only the spring specific pressure Psp determines the end face specific pressure Pc. Therefore, the larger sealing face pressure may be one of the causes of wear on the sealing face. (2) serious siltation of cooling water chamber, the cooling water is insufficient or even cooling, the sealing film between the liquid surface vaporization, resulting in increased sealing surface wear, auxiliary sealing ring aging and other issues. The formation of scale is that when the raw water is heated, the temperature rises, and the soluble Ca (HCO3) 2 and Mg (HCO3) 2 in the water start to precipitate when heated to about 80 degrees. The precipitation of Ca (HCO3) 2 and Mg The inner wall forms scale. (3) sealing chamber temperature is too high, hot ring seal ring softening, and the sleeve together, resulting in the ring can not move freely along the axial direction to compensate for the wear or displacement of moving ring, which is a large number of shaft seal leakage splashed The main reason.
Improvement measures The moving ring made of aluminum oxide ceramic material, its high hardness, wear resistance number, but poor thermal shock resistance, brittleness, if the pump shaft or rotor axial movement often lead to crack sealing surface; In addition, the seal Large changes in surface temperature is also likely to cause stress concentration caused by sealing surface cracks. So moving ring to tungsten carbide YG6, its toughness and rigidity particularly large, wear resistance is also better, suitable for sealing high temperature water medium, re-machining ring seat, moving ring inlaid therein. In order to ensure the sealing performance, based on the failure analysis of the auxiliary seal, the auxiliary seal must have good elasticity and high temperature resistance, and the seal ring of the movable ring adopts O-type fluorine rubber seal. Because carbon graphite has good self-lubricating and high temperature ability to work, and carbide pairing is better, so the static seal still retains carbon graphite, static seal agreed to the use of fluorine rubber.