Stainless steel multi-stage submersible pumps are mainly made of stainless steel wear-resistant materials. They are used to submerge into the water to extract groundwater that has reached the pumping medium. The materials are: 304 stainless steel submersible pumps, 316 stainless steel deep well submersible pumps, 316L stainless steel submersible pumps The main application and environment are relatively harsh, and the medium has certain corrosive conditions. In the working process of stainless steel multi-stage submersible pump, it is inevitable that some minor faults will affect the operation of the submersible pump and cause some minor problems. Different faults and maintenance methods are also different. This article mainly summarizes the phenomenon and maintenance of stainless steel multi-stage submersible pumps. Methods and general maintenance and use items.
1. Difficult to start or unable to start
If the switch is turned on, the fuse will be blown immediately or the motor will only buzz and not rotate or the rotation speed will not reach the rated speed. All belong to start-up failures. Generally there are electrical and mechanical reasons:
Electrical aspects: (1) The voltage is low and the motor starting torque is not enough. The main reason is that the voltage of the power supply system itself is low, the capacity of the transformer is not enough, or the water pump is too far away, or the cross section of the power supply wire is too small. (2) One-phase power supply is broken or one-phase fuse is blown, causing the motor to start in two phases. (3) The steering of the motor is wrong, and any two of the three live wires should be adjusted and connected.
Mechanical aspects: (1) If the pre-moisturizing water is not filled or the amount of pre-moisturizing water is insufficient before starting, it should be filled with pre-moisturizing water. (2) The drive shaft and the rubber bearing are not properly matched, and the clearance is too small. (3) The drive shaft is bent or the axial clearance of the impeller is not adjusted properly, causing friction or jamming, and it should be repaired or adjusted. (4) There are sundries in the pump that jam the impeller or there is sediment in the pump body and bearings, which should be removed in time.
2. There is no water or the flow is very small after starting
The pump rotates after starting, but there is no water or the flow is small. It should be shut down immediately for inspection. A longer time may burn the rubber bearings and cause the pump to vibrate. The main reasons are:
(1) The pump body is not submerged deep enough in the water or the water level in the well drops too much, and the water inlet is exposed to the water surface to suck in air.
(2) Mud, sand and debris in the water block the inlet pipe, impeller or the flow channel of the water guide shell. The debris in the pump or well must be removed before the pump is installed.
(3) The impeller is loose, the drive shaft or the pump shaft is broken, and the shaft impeller does not rotate. This type of failure is caused by improper assembly of the pump body or excessive adjustment of the axial clearance.
(4) The water outlet pipe is broken or tripped, resulting in a large amount of water leakage, resulting in reduced water output or no water.
3. Strong vibration occurs during deep well pump operation
(1) Vibration during start-up may be caused by not adding pre-lubricated water or insufficient water added. Stop the machine and add pre-lubricated water immediately to avoid dry friction and cause the rubber bearing to hold the shaft after high temperature.
(2) The axial clearance of the drive shaft is too small, causing mechanical friction and collision between the impeller and the water guide shell, causing vibration, and it should be shut down immediately for inspection.
(3) The transmission shaft is bent or the rubber bearing is excessively worn, and the supporting function is lost, causing the transmission shaft to swing. The transmission shaft should be checked and straightened.
(4) The well pipe is not vertical, and the drive shaft and the water pipe are squeezed to cause vibration. The deep well pump should be removed to straighten the well pipe.
4. The power of the deep well pump increases during operation
If the reading of the ammeter or power meter on the switchboard increases suddenly, it means that the shaft power of the deep well pump is increasing and the motor is overloaded. The cause should be found out immediately and dealt with, and the motor overload time should be shortened as much as possible to avoid burning the motor. Reasons for increased shaft power of water pump:
(1) The axial clearance of the impeller is too small, causing mechanical friction between the impeller and the water guide shell, and the clearance should be adjusted by stopping the machine.
(2) The packing is too tight, so the gland nut should be loosened appropriately.
(3) If the motor bearing is damaged, the bearing should be replaced.
(4) The water contains a large amount of mud and sand, and the moving parts are blocked by the mud and sand, so the pump should be removed to clean the well.
Stainless steel multi-stage submersible pump maintenance process:
1. Minor repair of stainless steel multi-stage submersible pump
1) Mechanical seal: replacement and cleaning
2) Check the bearing and oil chamber, change the transformer oil
3) Eliminate defects and leaks found during operation, check and tighten all bolts.
4) Clean and repair the valve
2. Intermediate repair of stainless steel multi-stage submersible pump:
1) Including minor repairs.
2) Overhaul the mechanical seal, repair and replace parts.
3) Disassemble, check the degree of wear, corrosion and erosion of each part, and repair or replace it.
4) Check the wear, corrosion and straightness of the shaft, repair or replace it.
5) Check the wear of the bearing, scrape the bearing bush, adjust the gap, and replace the bearing.
6) Check and adjust the gaps of the impeller seal ring, shaft sleeve, gland, shaft seal and other parts.
7) Check the static balance of the impeller and the dynamic balance of the rotor.
8) Check, clean and repair the motor.
3. Overhaul of stainless steel multi-stage submersible pump:
1) Including mid-term repair content
2) Better and better impeller
3) Replace the pump shaft
4) Thickness measurement and identification of the pump body, and necessary repairs
5) Measure and adjust the level of the pump body to remove rust and corrosion.
Correct use of stainless steel multi-stage submersible pump
1. Check before starting
1) Check whether the steering of the stainless steel multi-stage submersible pump is correct and whether the connecting screws of each part are tightened: whether the packing gland tightness is appropriate; whether the electrical wiring and belt drive meet the requirements; whether the chemical pump non-reverse device is safe and reliable; motor bearings, The lubrication of the transmission and the pump seat.
2) Check whether the axial clearance of the submersible pump is well adjusted. The axial clearance between the impeller and the blade shell must be adjusted before starting. The impeller can meet the performance requirements without friction with the blade shell during operation. The deep well pump adopts adjusting nut to adjust the axial clearance. It is necessary to check whether the positioning screw on the axial clearance adjustment nut is tightened. If it is loose, tighten it immediately.
3) Check the pre-lubrication of rubber bearings. Because the static water level in the well is relatively deep. Dry friction will occur between the drive shaft and the rubber bearing when starting, causing vibration and bearing burnout. Therefore, the rubber bearing of the drive shaft must be pre-lubricated with water before starting the deep well pump.
2. Startup, operation and shutdown of stainless steel multi-stage submersible pumps
1) Start. The valve can be opened when starting, the deep well pump generally adopts reduced pressure to start, press the "start" button, the motor will start at a lower voltage and lower voltage.
2) Run. After the submersible pump is started for a few seconds to tens of seconds, the pump speed is close to normal, you can press the "Run" button, the motor immediately enters the normal speed to run, and the multi-stage pump discharges water normally. Observe the instructions of the ammeter, voltmeter and related instruments during operation. Always pay attention to whether the pump is running stable, whether the water output is normal, pay attention to the changes in the water level in the well, and regularly measure the static and dynamic water levels. The water level in the well is too low, so that the leaf is not submerged in depth enough, sucking in air, destroying the normal operation of the water pump, and even unable to pump water and wearing rubber bearings. Pay attention to the amount of mud and sand in the effluent during operation. After a large amount of mud and sand is sucked by the pump, it will cause mechanical failure and overload the motor. The gate valve should be opened slowly, so as not to raise the water sharply. You should open the gate valve while paying attention to the amount of sand gushing out.
3) Shut down. Press the "stop" button to start the compensator to stop the stainless steel multi-stage submersible pump. Before stopping the machine, close the gate valve on the outlet pipe and then cut off the power supply. When all the water in the water pipe does not flow back to the well after the shutdown, the pump must not be restarted to avoid excessive starting power and malfunction. Generally, it should be restarted after 10-15 minutes.
