V. Mechanical Seal Structure and Maintenance
- Maintenance
(1) Pay attention to whether there is any loosening and leakage of the mechanical seal components or abnormal heating and noise caused by impurities entering the end face; prevent dry friction. For intermittently operated machinery, pay attention to the crystallization formed by drying of the medium or the precipitation of crystals due to a temperature decrease after stopping. Take measures such as heating or flushing during startup to prevent end face damage.
(2) Observe whether auxiliary devices such as flushing, cooling, and instruments are working normally.
(3) Pay attention to any abnormal phenomena during machine operation, such as vibration or bearing damage, which will affect the use of the mechanical seal.
- Overhaul
(1) Requirements for disassembly work:
① Familiarize yourself with relevant information, drawings, and the type structure of the mechanical seal before disassembly.
② Make preparations, prepare necessary facilities and tools, and take safety precautions.
③ Disassemble in order, make marks for easy reassembly, and observe, analyze, and identify the causes of leaks during disassembly.
④ Store the removed old parts for some time before disposal. In the absence of information or incomplete information, new parts can be obtained based on the material and specifications of the old parts.
(2) Overhaul methods
① When the surface of the dynamic or static ring is severely worn or cracked, replace it with a new one; shallow scratches can be polished. Check the perpendicularity deviation between the end face of the dynamic and static rings and the axis centerline. If it exceeds 0.05mm, adjust or repair it.
② Replace the auxiliary seal ring and spring when damaged; when selecting the spring, ensure that the end face is parallel and perpendicular to the centerline, and try to make the free height and deformation as consistent as possible.
③ Adjust the axial movement to the specified range.
④ Check whether the shaft or shaft sleeve is worn. If there is wear, perform welding, heat treatment, and machining in a timely manner.