| 摘要 |
<p>BACK-UP MECHANICAL SEAL : A pump assembly having an impeller (14) for pumping a fluid from an intake (30) to an outlet (33), a prime mover for driving the impeller, and a primary mechanical seal assembly (26) between the prime mover and the impeller which is located in a housing. The mechanical seal assembly substantially prevents leakage of the fluid being pumped along a shaft connecting the impeller and the prime mover. A secondary mechanical seal means (28) is located in the housing between the prime mover and the mechanical seal assembly. The secondary seal means is constructed of a material, such as carbon, which will collapse under pressure of the fluid being pumped upon failure of the primary mechanical seal assembly, to substantially prevent the leakage of fluid along the shaft and to the exterior of the housing.</p> |
