Precautions for the installation and use of centrifugal pumps

1. Confirmation of the sealing components:

(1) Verify that the installed seal is of the required model.

(2) Before installation, carefully compare with the overall assembly diagram to ensure that the quantity of parts is complete. Check for any scratches or defects on the friction pair, sealing ring, gasket, etc. If any abnormal phenomenon is found, it must be repaired and qualified before use. Parts that do not meet the requirements shall not be installed.

(3) For mechanical seals using spiral springs, the springs have left and right rotations. The selection of the rotation direction must be based on the rotation direction of the shaft. If the rotation direction is incorrect, the transmission function will be lost, leading to seal failure. The method to determine the rotation direction is: from the back end of the installation of the stationary ring facing the direction of the moving ring assembly, when the shaft rotates clockwise, the right-hand spring should be used; otherwise, the left-hand spring should be used.

2. Installation:

The installation method varies depending on the type of mechanical seal and the type of machine, but the installation principles are almost the same. The installation steps and precautions are as follows:

(1) Position confirmation

The working length of the mechanical seal installation is based on the requirements of the overall assembly diagram. The compression amount of the spring depends on the positioning size of the spring seat on the shaft. Before determining the installation position, fix the relative position of the shaft and the sealing chamber housing. Take the vertical end face of the housing perpendicular to the shaft as the reference and mark on the shaft. Then calculate the positioning size of the spring seat.

(2) Installation

Before installation, the shaft (or shaft sleeve) and the cover plate should be free of burrs and in good bearing condition; the sealing components, shaft, sealing chamber, cover plate should all be cleaned. To reduce friction resistance, a thin layer of oil should be applied to the area where the mechanical seal is installed on the shaft for lubrication. Considering the compatibility of ethylene propylene rubber, oil should not be used. Soap water can be used instead. First, install the non-compensating ring and the cover plate together on the shaft, pay attention not to collide with the shaft to avoid damage to the sealing ring; then install the compensation ring assembly. The tightening screws of the spring seat or transmission seat should be tightened evenly in several stages.

Before fixing the cover plate, check if there are any foreign substances adhering to the contact surface of the friction pair. Push the compensation ring axially with your hand, and after releasing, the compensation ring can automatically return without any jamming phenomenon. Then evenly lock the cover plate screws.