The Cause of Mechanical Seals Leakage of Centrifugal Pumps and Maintenance Methods

Centrifugal pump mechanical seal leakage causes and maintenance methods: First, sudden leakage during normal operation. Centrifugal pump in operation suddenly leaked a few due to normal wear and tear or have reached the service life, and most are due to larger changes in operating conditions or operation and maintenance caused by improper. 1, evacuated, cavitation or a longer time holding pressure, leading to seal damage; 2, the actual output of the pump is small, a large number of medium pump cycle, heat accumulation, causing gasification medium, leading to seal failure; 3, Large, resulting in suction side of the tube side of the container (tower, kettle, tank, pool) at the bottom of sediment thrown, damaged seal; 4, for a long time outage, restart without manual turning, friction due to adhesion and tear seal Surface; 5, medium corrosive, polymeric, colloidal substances increased; 6, rapid changes in ambient temperature; 7, frequent changes or adjustments in operating conditions; 8, Suddenly blackouts or downtime and so on. Centrifugal pump suddenly leaks in normal operation, if it can not be found in time, it will often lead to a larger accident or loss, which should be taken seriously and effective measures should be taken. Second, pump mechanical seal repair errors and correct maintenance methods: 1, the greater the amount of spring compression seal the better. In actual fact, the spring compression is too large, can lead to rapid wear and tear of the friction pair, instantaneous burning; excessive compression of the spring lost the ability to adjust the dynamic ring end face, leading to seal failure. So to choose the appropriate amount of spring compression. 2, moving ring seal chart as tight as possible. In fact, the ring is too tight moving ring harmless. One is to aggravate the wear and tear between the seal ring and the sleeve, premature leakage; the other is to increase the axial resistance of the moving ring, the resistance of the movement can not be adjusted in time when the working conditions change frequently; the third is excessive fatigue and easy to damage the spring; Is to move the ring ring deformation, affecting the sealing effect. 3, static ring seal as tight as possible. Static ring seal is basically static, the relatively tight seal will be better, but too tight is also harmful. First, the static ring seal caused by over-deformation, affecting the sealing effect; Second, static graphite material to the majority, generally more brittle, excessive stress can easily cause fragmentation; Third, the installation and removal difficulties, can easily damage the static ring. 4, the impeller locker tighter and better. Mechanical seal leakage, the sleeve and shaft leakage (shaft leakage) is more common. Generally believed that the leakage between the shaft impeller lock is not locked, in fact, leading to leakage between the shaft more factors, such as the shaft pad failure, offset, impurities within the shaft, shaft and sleeve with a larger shape Bit error, contact surface damage, there is a gap between the various components on the shaft, the shaft thread is too long and so will lead to shaft leakage. Over-locking the lock will result in premature failure of the shaft pad. So as long as the appropriate locking lock mother, the shaft pad always maintain a certain degree of compression flexibility, in operation, lock the mother will automatically timely lock, the shaft is always in good seal. 5, the new better than the old. Relatively speaking, the use of new mechanical seal effect is better than the old, but the new mechanical seal quality or material selection is not appropriate, with the larger size error will affect the sealing effect; In polymeric and permeability medium, the static ring without excessive Wear, or not replaced as well. Because the static ring in the static ring seat for a long time in a quiescent state, the polymer and impurities deposited as one, played a better seal. 6, the demolition is better than not demolished. In the event of a mechanical seal leak eager to repair, in fact, sometimes the seal is not damaged, just adjust the condition or adjust the seal to eliminate leakage. This will not only avoid waste but also verify their ability to determine the fault, the accumulation of maintenance experience to improve the quality of overhaul.