Introduce to cooling tower pump
As one of the core equipment of the cooling system, the normal operation of the cooling tower water pump directly affects the heat dissipation efficiency of the entire system. The pump shaft seal (usually a mechanical seal) is a key component that prevents water leakage along the pump shaft. With long-term operation, the shaft seal may experience wear, aging, leakage, and other conditions, and needs to be replaced in a timely manner to ensure the normal operation of the equipment.
Preparation work
1. Tool preparation
1) wrench set
2) hex key
3) screwdriver
4) rubber mallet
5) Puller (if coupling needs to be disassembled)
6) Clean cloth, non-woven fabric
7) Protective gloves and goggles
2. Material preparation
1) New mechanical seal component (model must be consistent with the original pump)
2) Lubricating oil or clean water (used for lubrication during installation)
3) Sealing gasket, fill and other related auxiliary materials (if any)
3. Safety preparation
1) Cut off the power and hang the "No Operation" sign
2) Close the inlet and outlet valves and drain the water from the pump body
3) Wait for the pump body to completely cool down
Steps for replacing mechanical seals
Step 1: Remove the coupling protective cover
Loosen the fixing screws of the protective cover, carefully remove them, and expose the coupling between the motor and the pump.
Step 2: Release the coupling
According to the type of coupling (elastic coupling, plum blossom coupling, etc.), loosen the connecting bolts to separate the motor and pump.
Step 3: Disassemble the rear cover or bearing seat of the pump body
After removing the fixing bolts, gently tap the end cover to detach it from the pump body.
Step 4: Extract the pump shaft assembly
According to the structure of the pump, disassemble the impeller, shaft sleeve and other components in sequence to avoid using brute force.
Step 5: Remove the old mechanical seal
Usually divided into two parts:
1) Static ring (installed on the end cover of the pump body)
2) Dynamic ring (installed on the shaft sleeve or shaft)
Carefully remove with a screwdriver or pry bar to avoid scratching the sealing chamber or shaft.
Install a new mechanical seal
Step 6: Clean the sealing installation surface
1) Clean the sealed chamber
2) Check for wear on the shaft or sleeve
3) Ensure that the sealing surface is smooth and free of foreign objects
Step 7: Install the static ring
1) Lightly lubricate the outer ring of the stationary ring
2) Apply average force to press into the sealed chamber
3) Ensure that the end face of the static ring is flat and not tilted
Step 8: Install the dynamic ring component
1) Install the moving ring, spring, and spring seat in sequence
2) The lip surface of the moving ring must be clean, and it is forbidden to touch the end surface before installation
3) Push the moving ring smoothly into the designated position on the shaft
Step 9: Restore the pump shaft assembly
1) Reinstall the impeller, shaft sleeve, end cover, etc. in the reverse order of disassembly
2) All bolts should be tightened evenly diagonally
Step 10: Calibrate the coupling
1) The concentricity between the motor and the water pump must be good
2) Axial/radial deviation generally needs to be controlled at around 0.1mm (according to the manufacturer's requirements)
Step 11: Trial operation check
1) Open the inlet valve and fill the pump body with water
2) Slightly open the outlet valve
3) Power on and test run to check for leaks or abnormal sounds
4) Adjust the operating traffic
Precautions
1) The mechanical sealing surface should not be directly touched by hand to prevent oil stains from affecting the sealing effect.
2) At the initial stage of shaft seal leakage, the cooling water quality, water pump vibration, and bearing wear should be checked.
3) When installing the dynamic and static rings, the end face must be kept clean and flat.
4) If severe wear is found on the pump shaft, the shaft or sleeve should be replaced, otherwise it will cause the new seal to fail quickly.
5) The first start-up after replacement should be carried out under normal inlet pressure and with the pump body filled with water to avoid dry grinding.
