1. The requirements of mechanical seals for machine accuracy (take mechanical seals for pumps as an example)
(1) The radial runout tolerance of the shaft (or sleeve) where the mechanical seal is installed does not exceed 0.04～0.06MM.
(2) The axial movement of the rotor does not exceed 0.3MM.
(3) The runout tolerance of the positioning end of the sealing cavity and the sealing end cover facing the surface of the shaft (or sleeve) does not exceed 0.04～0.06MM.
2. Confirmation of mechanical seal for pump
(1) Confirm whether the installed seal is consistent with the required model.
(2) Check carefully with the final assembly drawing before installation, and check whether the number of parts is complete.
(3) The mechanical seal is driven by a parallel spring. The spring can be divided into left and right rotation, which must be selected according to the rotation direction of the shaft.
3. Installation of mechanical seal of water pump
The installation method varies with the type of mechanical seal and the type of machine, but the installation essentials are almost the same. The installation steps and precautions are as follows:
During installation, the installation size of the mechanical seal should be ensured according to the product's instruction manual or sample.
(2) Before installation, the shaft (sleeve) and gland should be free of burrs, and the bearing should be in good condition; the seals, shaft, seal cavity, and gland should be cleaned. In order to reduce frictional resistance, the part where the mechanical seal is installed on the shaft should be coated with a thin layer of oil for lubrication, taking into account the compatibility of rubber O-rings
If it is not suitable to use oil, soapy water can be applied. The floating static ring has no anti-rotation pin structure, so it is not suitable to be oiled and should be dry-mounted in the gland.
(3) Install the static ring and gland on the shaft first, taking care not to collide with the shaft, and then install the moving ring assembly. The set screws of the spring seat or transmission seat should be tightened evenly in several times. Before fixing the gland, push the compensation ring by hand for axial compression. After loosening, the compensation ring can automatically spring back without jamming, and then evenly lock the gland bolts.
4. Use of pump mechanical seal
(1) When the temperature of the conveying medium is too high, too low, or contains impurity particles, is flammable, explosive, or toxic, take corresponding measures such as blocking, washing, cooling, and filtering.
(2) Before operation, turn the car by hand, pay attention to whether the torque is too large, whether there is rubbing or abnormal sound.
(3) Pay attention to the direction of rotation, whether the coupling is centered, whether the lubricating oil at the bearing part is added properly, and whether the piping is correct.
