Mechanical seal of the symptoms and elements
Mechanical seal parts of the rotation equipment in the running side, sealed face often show wear, hot cracking, deformation, damage and other conditions, tension with a long time will be loose, cracking and corrosion. Auxiliary seal will also show cracks, distortion and deformation, break and other conditions.
Mechanical seal oscillation, fever problems elements.During the rotation of the device, the dynamic ring conforms to the rough face, and the gap between the dynamic ring and the seal cavity is too small, because the vibration causes the bump to cause oscillation. Sometimes due to sealing the end of the corrosion resistance and poor temperature function, or lack of cooling or face in the device when the folder with particles of impurities, will also cause the mechanical seal of the oscillation and heat.
Mechanical seal media leakage of the elements of the problem
Static pressure test leak. Mechanical seal in the device because not careful, usually the sealing end of the face was bumped, deformation, damage, finishing is not net, with granular impurities, or because the positioning screw loose, gland is not pressed, the machine, equipment accuracy , So that the sealing surface is not completely fit, will form a media leak. If the shaft is leaked, it is not compressed or tightened or not damaged when the sleeve seal is installed. Periodic or paroxysmal leakage. Mechanical seal of the rotor components of the periodic oscillation, axial movement is too large, will form a leak. Mechanical seal of the sealing surface to have a certain pressure, so the ability to play a sealed role, which requires the mechanical seal of the torsion spring to have a certain amount of compression, to the sealing end of a thrust, rotating up to seal the sealing request More pressure. In order to ensure that this one pressure, mechanical seal request pump shaft can not have too much channeling, usually to ensure that within 0.25mm. But in the practice planning side, because the planning is unreasonable, usually pump shaft occurs a lot of channeling, the use of mechanical seals is very bad luck. Mechanical seal of the regular leakage. There are many aspects of the mechanical seal often leaks. Top of the list, because the shortcomings of the seal end of the regular leakage caused. The second aspect is the auxiliary seal caused by the frequent leakage. The third aspect is the fault caused by the shortcomings of tension. In other respects, it also contains leakage, transmission, tightening and thrust parts caused by rotor oscillation, resulting in poor quality or loosening of the parts, mechanical leaks caused by the organization of the mechanical seal. Mechanical seal oscillation is too large. Mechanical seal oscillation is too large, eventually resulting in the loss of sealing effect. But the mechanical seal is too large elements of the mechanical seal itself is not only the elements of the pump, the other parts of the pump is also the origin of vibration, such as pumping shaft planning is unreasonable, the processing of elements, bearing accuracy can not, the parallelism of the coupling Poor, radial force and other elements.
Ways to deal with the adoption of the problem
If the mechanical seal parts are defective, you need to replace parts or progressive parts of the machining accuracy, improve the mechanical seal their own processing accuracy and the processing of other parts of the pump body parts of the mechanical seal is very beneficial. In order to improve the sealing effect, the dynamic ring of the conflict surface of the brightness and unevenness of the request is higher. The width of the conflicting surface of the dynamic ring is not large, usually between 2 and 7 mm.
Mechanical seal oscillation, heat treatment
If the gap between the dynamic ring and the sealed cavity is too small, it is necessary to increase the inner diameter of the seal chamber or reduce the rolling outer diameter, at least 0.75mm to ensure the gap. If the conflict is not correct pairing, it is necessary to change the dynamic ring material, so that temperature, corrosion resistance. This will cut the mechanical seal of the oscillation and heat.
Mechanical seal leakage treatment
Mechanical seal leak is due to a variety of factors, we have to ask in detail detailed treatment. In order to reduce the amount of leakage, the mechanical seal must be strictly in accordance with the technical requirements of the device, together with the following matters.
(1) device to clean and bright. Mechanical seal parts, tools, smooth oil, wipe the material to be very clean. The seal end face of the dynamic ring is wiped with a soft gauze. (2) trim chamfering round. Shaft, sealed cover and other chamfers to be trimmed smooth, the shaft and the cover of the fillet to sand polish. (3) device auxiliary seal ring, the rubber auxiliary seal cannot use gasoline, kerosene soaking scrub, to avoid swelling deformation, premature aging. Dynamic ring assembly, the hand press the compensation ring, check is not in place, is not sensitive; elastic ring is not positioning solid. After moving the ring device, it is necessary to ensure that it is sensitive to axial movement on the shaft.
Pump shaft channeling large processing
Reasonable planning of the axial force of the balance of equipment, to eliminate the axial channeling. In order to satisfy this request, on the multi-stage centrifugal pump, the planning scheme is: the balance plate and the axial thrust bearing, the axial force is balanced by the balance plate, and the axial limit is restricted by the axial thrust bearing.
Add auxiliary washing system
Sealed chamber sealed medium rich in particles, impurities, it is necessary to scour, or because of the crystallization of the separation, particles, impurities in the accumulation of mechanical seal of the tension spring failure, if the particles into the conflict, will lead to mechanical seal of the agile damage. Therefore, the mechanical seal of the auxiliary scouring system is very important, it can effectively maintain the sealing surface, play a cooling, smooth, washed away debris and so on.
In the process of production of pump products, in strict accordance with the norms and procedures to perform, to eliminate the source of oscillation. Pump, motor, base, field piping and other auxiliary equipment in the field device, to strict checks to eliminate the source of oscillation.
Above a brief discussion of the mechanical seal on the use of rotating equipment and the emergence of the problems, and later encountered mechanical seal problems, the first to consider the mechanical seal of their own elements of influence, and then think about the mechanical seal outside the impact of some of the elements. For example: in the analysis of mechanical seals of the quality of the accident elements, to consider the other parts of the pump on the mechanical seal of the impact of the adoption of methods to continue to improve the role of mechanical seals.