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Installation Process of Mechanical Seals I. Installation Methods The installation methods vary depending on the type of mechanical seal and the kind of machine, but the basic principles remain similar. The installation steps and precautions are as follows: 1. Determination of installation dimensions During installation, it is necessary to adhere to the installation dimensions specified in the product’s instruction manual or specifications. 2. Before installation, the shaft (shaft sleeve) and gland should be free of burrs, and the bearings should be in good condition; the seals, shaft, sealing chamber, and gland must all be thoroughly cleaned. To reduce frictional resistance, a thin layer of oil should be applied to the portion of the shaft where the mechanical seal is installed for lubrication. Considering the compatibility of rubber O-rings, if oil is not suitable, soapy water can be used instead. The floating static ring, which lacks an anti-rotation pin, should not be oiled and must be installed in the gland in a dry state. 3. First, install the stationary ring together with the gland on the shaft, being careful not to let it touch the shaft, and then insert the rotating ring assembly. The set screws of the spring seat or drive seat should be tightened in several stages evenly. Before fixing the gland, manually compress the compensating ring axially; once released, the compensating ring will spring back automatically without any sticking, and then the gland screws should be tightened evenly. 4. Another thing to note: It’s not the case that the static ring seal should be tighter the better. The static ring seal is essentially at rest, which results in a better sealing effect; however, being too tight is also harmful. First, excessive deformation of the stationary ring seal can affect its sealing performance. Second, the stationary ring is usually made of graphite, which is relatively brittle, and excessive stress can easily cause it to break. Third, installation and removal are difficult, which can easily lead to damage to the stationary ring. II. Precautions during installation 1. Before installation, carefully check whether there are sufficient numbers of sealing parts, and whether all components are intact; in particular, inspect the moving and stationary rings for any defects such as scratches, cracks, or deformation. If there is a problem, it needs to be repaired or replaced with new spare parts. 2. Check whether the chamfer on the shaft sleeve or gland is appropriate; if it does not meet the requirements, it must be trimmed. 3. All components of the mechanical seal, as well as the relevant assembly contact surfaces, must be thoroughly cleaned with acetone or anhydrous alcohol before installation. Cleanliness should be maintained during installation, especially the moving and stationary rings as well as the auxiliary sealing elements must be free from impurities and dust. Coat the surfaces of the rotating and stationary rings with a layer of clean engine oil or turbine oil. 4. The upper gland should be tightened after the coupling has been aligned. The bolts should be tightened evenly to prevent skewing of the gland cross-section; a feeler gauge or special tool should be used to check each point, with the error not exceeding 0.05 millimeters. 5. Check the clearance (and concentricity) between the gland and the outer diameter of the shaft or bushing; it must be uniform all around. Use a feeler gauge to verify that the tolerance at each point does not exceed 0.10 mm. 6. The compression amount of the spring must be in accordance with the specified values; it is not allowed to be too large or too small. The allowable error is ±2.00 millimeters, as a larger compression amount will increase the stress on the cross-section and accelerate its wear. If it is too small, the pressure will be insufficient to provide a seal; once the spring is installed, it must be able to move freely within the spring seat. When using a single spring, pay attention to its rotation direction; it should be opposite to the rotation direction of the shaft. 7. After installation, the moving ring must be able to move freely; it should return automatically after being pressed against the spring. 8. First, fit the static ring seal ring around the back of the static ring, and then insert it into the sealing end cover. Be careful to protect the cross-section of the stationary ring, ensure its perpendicularity to the center line of the end cover, and align the anti-rotation groove on the back of the stationary ring with the anti-rotation pin, ensuring that they do not come into contact with each other. 9. It is strictly prohibited to strike the sealing element directly with tools during installation; if striking is necessary, special tools must be used to avoid damaging the sealing element.