Common faults and treatment of mixed flow pump

 

In practice, troubleshooting should be based on specific problems and actual analysis. The principle of "outside first, then inside" should be followed, and blind operation is not allowed.
First of all, it is necessary to inspect the power supply: whether the connectors are firmly connected; Whether the switch contact is meticulous; Whether the fuse is blown; Whether the three-phase power supply lacks equality. If there is an open circuit, poor contact, blown fuse, or lack of phase, the cause should be identified and repaired in a timely manner. Secondly, check whether it is a mechanical fault of the water pump itself.
Symptom 1: The water pump cannot be started
Common causes: packing is too tight or the impeller and pump body are blocked by debris accumulation; The pump shaft, bearing, and leakage reduction ring are rusted; The pump shaft is severely bent, etc.
Troubleshooting: Loosen the filler and dredge the water diversion channel; Disassemble the pump body to remove debris and rust; Remove the pump shaft for correction or replace with a new pump shaft.

Vacuum Pump: Difference Between Oil Type And Oil Free Type 

Analysis of low efficiency of multistage centrifugal pumps

The pump shaft of a multistage centrifugal pump is equipped with more than two impellers in series, which can achieve a higher lift compared to ordinary single stage centrifugal pumps; Compared to reciprocating pumps such as piston pumps and diaphragm pumps, it can pump a larger flow rate. Multistage centrifugal pumps have high efficiency and can meet the needs of high lift and high flow conditions. They are widely used in petrochemical, chemical, electric power, construction, fire protection, and other industries.
Due to the adoption of an energy-saving hydraulic model, multi-stage centrifugal pumps have the advantages of high efficiency and wide performance range, better meeting the user's operational requirements. In addition, this type of pump adopts a vertical and segmented structure, and features safe, stable operation, long service life, small floor space, and convenient safety and maintenance.
Reasons for low efficiency of multistage centrifugal pumps:
① During installation, the pump, torque and speed sensor, and drive motor are not concentric.
② There is a deviation in the zero adjustment of the dynamometer, or the steering direction is inconsistent.
③ There is a fault with the torque speed sensor or torque display.
④ The packing is too tight or the preload of the mechanical seal is too large.
⑤ The balancing mechanism does not function, increasing the axial force.
⑥ The multi-stage pump bearing is damaged.
⑦ Poor design and manufacturing quality of impellers and other flow passage components.

ProPak China & FoodPack China 2023

Why do some screws on centrifugal pumps and chemical pumps use hexagon socket screws

 

As we all know, screws are indispensable fasteners for chemical equipment, and fasteners such as chemical pumps and centrifugal pumps are fixed with screws. There are many ways to fix screws, such as outer hexagon and inner hexagon. Today, we will talk about why hexagon socket screws are used on pumps.
The outer edge of the screw head of the hexagon socket screw is circular, and the center is a recessed hexagon. In fact, the advantages of such a structure are obvious.
1. Easy installation. Compared to the outer hexagon screw, the inner hexagon is suitable for more assembly occasions, especially narrow occasions. Therefore, it is very convenient for assembly and maintenance, as well as for debugging.
2. Can be buried in the head. That is, the entire nut is sunk into the interior of the workpiece, which can maintain the flatness and aesthetics of the workpiece surface.
3. More load bearing. It has six force bearing surfaces, making it more capable of being tightened than flat head screws and cross head screws with only two surfaces.
4. Not easy to disassemble. "Our commonly used tools include adjustable end wrenches, screwdrivers, and solid wrenches. However, special wrenches must be used to disassemble hexagon socket bolts. Therefore, it is not easy for ordinary people to disassemble, which is also a benefit.".
Note: The materials of hexagon socket bolts are generally made of stainless steel, carbon steel, and alloy steel, and there is basically no difference between the materials of other types of screws. The higher the performance level, the greater the strength. When selecting screws, it is necessary to strictly follow the use requirements to select the appropriate performance level of screws, with different grades and prices
The outer hexagon screws are exposed to the outside, and the wrench requires a certain amount of space to tighten them, requiring a large or protruding counterbore. "The inner hexagon requires very small counterbores, and when space is not considered, the inner hexagon is basically a chicken rib.". Therefore, the application of screws depends on the application situation.

Ceramic Factory for Special Vacuum System Scheme

Common problems of vertical submerged sewage pump

Common fault I. Bearing heating
1. Too much grease, poor grease;
2. If the bearing is defective, replace the lubricating grease every 4 months. The amount of lubricating grease is 1/2 of the large bearing capacity. Replace the bearing when the high bearing temperature is less than 70 ℃.
Common fault 2: the outlet pressure drops and the flow is insufficient
1. Low speed of impeller and runner;
2. The pump body mouth ring is worn;
3. The suction inlet is blocked, replace or repair the impeller, replace the sealing ring and remove the blockage;
4. The liquid viscosity changes because the lift and flow rate decrease with the increase of liquid viscosity, so the specified viscosity must be maintained;
Common fault 3: severe vibration
1. The verticality after installation is out of tolerance
2. Shaft sleeve wear
3. Shaft bending
4. Impeller blocked or jammed by sundries
5. If the bearing is defective, adjust it to obtain enough verticality. Replace or adjust the bushing. Replace the shaft. Remove the sundries. Replace the bearing
Common fault 4: motor overload
1. The delivery flow exceeds the specified value
2. The reduction of output flow due to the friction between the impeller and the pump body seal ring may be due to the bending of the shaft, the serious friction of the rolling bearing and the improper adjustment of the clearance between the bearings, which must be eliminated.

The Principle, classification and scope of application of vacuum gauges

What is the working principle and model meaning of pipeline pump?

Pipeline pump has become one of the commonly used booster pumps in industrial applications. Pipeline pump is mainly used in HVAC cold and hot water circulation, industrial urban water supply and booster water supply for high-rise buildings. For its working principle and key points of use, Longyang Pump Valve will take you to introduce the working principle of pipeline pump, the meaning of pipeline pump model and the key points of use, so that you can clearly understand the pipeline pump and how to use it.
Working principle of pipeline pump
The pipeline pump can send water out because of the centrifugal force. Before the pump works, the pump body and the inlet pipe must be filled with water to form a vacuum state. When the impeller rotates rapidly, the blade drives the water to rotate quickly. The rotating water flies away from the impeller under the action of centrifugal force. After the water in the pump is thrown out, the central part of the impeller forms a vacuum region. Under the action of atmospheric pressure (or water pressure), the water from the water source is pressed into the inlet pipe through the pipe network. In this way, continuous pumping can be realized.
It is worth mentioning that the pipeline pump must be filled with water in the pump casing before starting, otherwise the pump body will be heated, vibrated, the water output will be reduced, and the pump will be damaged (referred to as "cavitation"), resulting in equipment accidents! There are many types of pipeline pumps, and the common classification methods are as follows: 1. According to the impeller suction method, it is divided into vertical pipeline pump, horizontal pipeline pump, multistage pipeline pump and hot water pipeline pump. According to impeller structure: open impeller centrifugal pump semi-open impeller centrifugal pump closed impeller centrifugal pump. According to working pressure: low-pressure centrifugal pump, medium-pressure centrifugal pump, high-pressure centrifugal pump, vertical centrifugal pump.

DLV Liquid Ring Vacuum Pump Seal

Five advantages of pipeline pump

 

Pipeline centrifugal pump is a new pump developed for pipeline pressurization and transportation to solve the problem of low pipeline pressure, which has great advantages over the current application of horizontal centrifugal pump. The advantages of pipeline pump are mainly reflected in the following points:
1. Pipeline pump is applicable to pressurization water supply of high-rise buildings, garden sprinkler irrigation, cooling tower water supply, long-distance water supply, air conditioning, refrigeration washing, bathroom and other cooling; Warm water circulation pressurization, operating temperature below 80 ℃.
2. It is applicable to high-temperature hot water pressurization cycle in heating, boiler and other industries. The operating temperature is below 150 ℃.
3. It is applicable to transport corrosive media in the process of food, pharmaceutical, wine making, chemical and other industries, with the service temperature below 80 ℃.
4. It is suitable for transporting non-corrosive liquids, and other industrial sites with methane or underground fixed equipment of Class I and factory Class IIA and IIB, and explosive mixture in temperature groups T1, T2, T3 and T4. The operating temperature is below 80 ℃.
5. Pipeline pump is suitable for conveying corrosive liquids in chemical, pharmaceutical, petroleum, food, national defense and other industries, including methane or other industrial sites with Class I underground fixed equipment in coal mines and Class IIA and IIB in factories, and explosive mixtures in temperature groups T1, T2, T3 and T4. The operating temperature is below 150 ℃.

Sugar factory compressor