The maintenance of centrifugal pump

The maintenance of centrifugal pump
Centrifugal pump mechanical seal failure analysis:
      Down mainly by the engine centrifugal pump mechanical seal failure caused. Failure of performance, mostly leaks, leaks following reasons:
     ① static ring sealing surface of the leak, the main reasons are: face flatness, roughness does not meet the requirements, or surface scratches; face between particulate matter, resulting in both ends of the same surface can not run; installed in place, the wrong way.
     ② compensation ring seal leakage, the main reasons are: gland deformation, uneven preload; not properly installed; seals do not meet quality standards; ring selection is wrong.
      Actual results show that the failure of most parts of the sealing elements are dynamic and static ring face, engine centrifugal pump mechanical seal dynamic and static ring face failure there is a common phenomenon of cracking, for two main reasons: ① Install the sealing surface when the gap is too large, fluid too late to take away the heat generated by friction; fluid leakage from the sealing gap in the walking surface, resulting in overheating and damage to the face. ② vaporization of liquid media expansion, so that both ends of the surface and separated by the expansive force of vaporization, when the two hard sealing surface lamination, resulting in destruction of the lubricant film face surface overheating. ③ poor lubrication liquid medium, coupled with operating pressure overload, the two sealing surfaces to track rotation is not synchronized. Such as high engine speed pump speed 20445r/min, center sealing surface diameter of 7cm, after the pump running speed of up to 75 m / s, when there is a lag can not track the rotating seal face, sealing surface damage caused by the instantaneous temperature. ④ sealing fluid orifice or filter clogged, causing water shortage, the mechanical seal failure.
      In addition, the surface smooth groove sealing surface, leading to end-lamination gap sealing component failure, for two main reasons: ① dirty liquid medium, there are small hard particles, people with high speed sliding sealing surface, the end surface of the designated injury and failure. ② poor pump coaxial transmission parts, each revolution of the pump is turned on end-sway friction was once the heart of different ring trajectory, resulting in end-vaporization, thermal wear. ③ hydraulic characteristics of the liquid medium caused by the frequent occurrence of pump vibration, resulting in the sealing surface dislocation and failure.
      Components of the sealing liquid medium corrosion, stress concentration, with the soft and hard materials, erosion, secondary seal 0-ring, V-shaped ring, concave ring is incompatible with the liquid medium, deformation will result in surface damage to the mechanical seal failure, so comprehensive analysis of its damage in the form to identify the root cause, to ensure the long-running mechanical seal.