Several Causes of Failure of Mechanical Seal of Centrifugal Pump
December 27 12:07:46, 2022
Centrifugal mechanical seal failure reasons: Centrifugal pump shutdown is mainly caused by the failure of the mechanical seal. Most of the failure performance of the leak, the leak for the following reasons: 1. The static and dynamic ring seal surface leakage mainly due to: the end flatness, roughness does not meet the requirements, or scratches the surface; between the end of the particulate matter, resulting in two Face can not be the same run; installation is not in place, the way is not correct. 2. Compensation ring seals are mainly due to leakage: gland deformation, uneven pre-tightening; installation is not correct; seal quality does not meet the standards; seal selection wrong. The actual use of the results show that the seal failure of the most parts of the dynamic and static end of the ring, the mechanical seal centrifugal pump, static ring end face cracking is a common phenomenon of failure, the main reasons are: â‘ sealing surface clearance is too large, Rinse liquid too late to take away the heat generated by the friction; Rinse liquid leak from the gap in the sealing surface, resulting in overheating and damage. â‘¡ vaporization of liquid medium expansion, so that the two ends by the expansion of vaporization and separation, when the two sealing surface force fit, the destruction of the lubricating film resulting in the end surface overheating. â‘¢ liquid medium lubrication is poor, combined with the operating pressure overload, two sealing surface tracking rotation is not synchronized. For example, high-speed pump speed of 20445r / min, the center of the sealing surface diameter of 7cm, pump speed after the line up to 75m / s, when there is a sealing surface can not track the hysteresis rotation, instantaneous sealing surface damage caused by high temperature. â‘£ seal flushing fluid orifice or filter plugging, resulting in insufficient water, so that the mechanical seal failure. In addition, the sealing surface of the surface of the groove, the end surface of the gap occurs when the gap sealing element failure, the main reasons: â‘ liquid medium is not clean, hard particles with a little hard, sliding surface with high speed, the end surface of the plan Injury and failure. â‘¡ poor coaxial pump drive parts, the pump is turned on each revolution after a week was shaking the friction end, moving the ring trajectory is not the same heart, resulting in end vaporization, overheating wear. â‘¢ frequent occurrence of hydraulic properties of liquid medium caused pump vibration, resulting in seal surface dislocation and failure. Liquid medium on the sealing element corrosion, stress concentration, with hard and soft materials, erosion, auxiliary seal O-ring, V-ring, concave ring and the liquid medium incompatible, deformation and so will cause mechanical seal surface damage failure, so Damage to the form of a comprehensive analysis to identify the root causes, to ensure long-term mechanical seal operation.