LG type multi-stage feed pump for high-rise buildings is a vertical single-suction multi-stage segmented centrifugal pump, which is used to transport room temperature water and liquids with physical and chemical properties similar to water.
LG series pumps are installed vertically. The motor shaft and the pump shaft are connected by a claw coupling, which has the advantages of compact structure, low noise, small footprint, etc.
Scope of application:
It is mainly used for water supply of high-rise buildings, and can also be used for water supply and drainage of factories and mines, and circulating water for low-pressure boilers.
1. Hydraulic model: reasonable design and wide range of performance.
2. Fewer operating and maintenance costs: mechanical seals are used, which are resistant to wear and tear, not easy to leak, have a long service life, low failure rates, and lower operating and maintenance costs.
3. Vertical structure, small footprint.
Flow: 3.0 -50m3 / h;
Head: 20 -150m ;
Speed: 2900r / min;
Temperature range: 0- + 80 ℃ ;
Working pressure: ≤1.2Mpa.
Fives, Model meaning:
Assembly and disassembly of the pump
Assembly of parts
1. Install the seal ring and bearing bush on the pump base. Fix them with set screws respectively.
2. Install the mouth ring on the middle section and fix it with set screws.
3. Set the guide vane on the guide vane. Fix the rear guide vane on the rear section with screws.
4. Press the balance drum sleeve into the rear section, and fix the rear guide vane on the rear section with screws. .
5. Install the packing in the stuffing room. Fix the stuffing gland on the stuffing body with stud bolts (25LG \ 32LG and 40LG pumps also need to install a water seal ring at the bottom of the stuffing room).
6. Install the bearing on the shaft. Secure it with a round nut and a backing pad 圏. Then install the bearing box with felt 圏 on the bearing, pay attention to inject the appropriate amount of calcium-based butter in the bearing box and the bearing. Then place the water-resistant 圏 paper pad and the sleeve C on the shaft. Insert the balance drum on the shaft With the key.
1. Pass the shaft through the packing chamber. Make the bearing box rest on the end face of the matching hole. Then install a bearing gland with a felt figure. Fix the bearing box and bearing gland on the support with a bolt.
2. Install the motor base on the support and fix it with bolts.
3. Turn the assembled parts of the shaft, support and motor base upside down, so that the motor base is at the bottom. The lower end of the shaft is facing up.
4. Install the 0-shaped seal on the support, and install the balance drum on the shaft (25LG \ 32LG and 40LG do not install O-rings and balance drums). Then install the rear section.
5. Embed the final stage impeller on the shaft, and install a final stage impeller and shaft sleeve B in turn.
6. Insert the middle section of the O-shaped seal into the pump shaft and install it on the rear section, and then install the guide vanes. 7. Repeat steps 5 and 6. Always install the first stage middle section and the first stage guide vanes.
8. Embed the first-stage impeller with 镩 on the shaft. Then place the first-stage impeller and the first-stage shaft sleeve B on the shaft in sequence.
9. Insert the shaft sleeve armor into the shaft with the key. Install the shaft sleeve armor. Then use two round nuts to fix it tightly.
10. Insert the sealing ring into the pump seat. Install the four tension bolts. Then install the pump seat on the middle section of the first stage. Note that the four tension bolts must pass through the four holes on the support.
11. Tighten the four tension bolts with nuts.
12. Turn the pump upside down. Fix the pump coupling with the key on the shaft, and then fix the motor equipped with the motor coupling on the motor base.
13. Install the return water pipe. The various parts, as well as the square plugs and oil cups of various parts. The pump is disassembled in the reverse steps described above.
Seven, pump start, run, stop and maintenance
1. Remove the surrounding area of the pump.
2. Fill an appropriate amount of calcium-based butter into the bearing box with an oil cup.
3. Adjust the tightness of the packing gland.
4.Check whether the rotation of the motor is consistent with that specified by the pump.
5. Open the bleed plug at the outlet flange and open the stop valve of the return line. Fill the pump with water through the funnel (no need to add water when pouring back).
6. Close the gate valve of the water outlet pipe and screw on the air vent screw plug.
7. The above work is completed. Start the motor.
8. After the pump is running at normal speed, gradually open the outlet gate valve until the required flow position and head are reached. When the pump is running for a long time, it should try to work within the specified flow position and head range. The pump is in operation. Should not Run beyond the high flow point in the performance table.
9. During operation, the temperature of the bearing must not exceed the external temperature, and the temperature should not exceed 75 ¡ã C.
10.It is advisable that the water leakage in the packing chamber is not linear, so as to maintain normal lubrication and cooling of the shaft and the packing.
11. When the pump shaft seal is a mechanical seal, it must be filled with water before starting to prevent the mechanical seal from running dry.
12. When the pump stops, close the gate valve on the outlet pipe first, and then stop the motor.
13. When abnormal noise is found during the operation of the pump, it should be stopped immediately to check its cause.
14. If the water pump is temporarily stopped during the winter freezing season, the drain plug on the tee at the lower end of the flush pipe must be unscrewed or 180 ¡ã away from the flange. Orient the drain plug on the pump base to drain the water stored in the pump to prevent the water from cracking.
15. After long-term use of the pump. When the flow and pressure drop significantly, the water pump should be disassembled for inspection, and its worn parts should be replaced.
16. When you stop using the water pump for a long time, the water pump should be disassembled. Dry the water on the pump parts. Remove the rust. And apply anti-rust grease, and then store it properly. During the period of inactivity, the pump must be stopped every Start to run once a month or so. The time should be no less than 5 minutes to ensure the reliable operation of the pump.
Eight, faults and troubleshooting
1.The pump does not absorb water. The pressure gauge pointer swings violently.
Insufficient water for priming and air leakage at the joint between the pipeline and the instrument.
Check the bottom valve for leaks. Then fill the drain valve, tighten or repair the leak.
2. The pump does not absorb water. The vacuum gauge indicates high vacuum.
The foot valve is not open or blocked. The suction pipe resistance is too high. The suction height is too high.
Overhaul the bottom valve. Replace the water pipe. Reduce the suction height.
3. The pressure gauge is under pressure, but still does not produce water.
The resistance of the outlet pipe is too large. The rotation direction is not correct, the impeller is blocked. The pump speed is insufficient.
Check or shorten the water pipe. Check the motor. Remove dirt from the impeller. Increase the pump speed.
4. The flow is lower than the design requirements.
Water pump is blocked, seal ring is worn too much. Insufficient speed.
Clean the water pump and pipeline. Replace the broken seal. Increase the pump speed.
5. The pump consumes too much power.
The packing pressure is too tight. It generates heat. The impeller is worn. The pump flow increases.
Adjust the tightness of the packing gland and check whether the pump shaft is distorted. Replace the impeller. Increase the water resistance. Reduce the flow.
6.Mechanical seal leakage
The friction pair is severely worn or the sealing surface is scratched.
Replace with new mechanical seal. Reground seal surface.
7.The sound in the pump is abnormal.
The resistance of the suction pipe is too large. The suction pipe leaks air. The temperature of the delivered liquid is too high.
Check the suction pipe and foot valve. Block the air leak, reduce the height of water absorption, and lower the water temperature.
8, pump vibration. Bearing overheating.
The motor is not concentric with the pump. The bearing is out of oil or worn.
Adjust the coaxiality of the motor shaft and the pump shaft. Refuel or replace the bearing.