What are the maintenance instructions for the magnetic pump?

Magnetic pump is a new product newly developed by Jiangda Pump Industry, which overcomes some shortcomings of gear oil pump,

1. Broken shaft

The magnetic pump shaft is made of 99% aluminum oxide porcelain. The main reason for the fracture of the pump shaft is that the pump runs empty,

2. The lift is insufficient.

The reasons for this failure are: there is air in the conveying medium, the impeller is damaged, the rotating speed is insufficient, the proportion of the conveying liquid is too large, and the flow is too large.

3. The bearing is damaged.

The magnetic pump bearing is made of high-density carbon. If the water supply of the pump is cut off or there are impurities in the pump, the service life of the bearing will be directly affected.

4. Insufficient flow.

The main causes of insufficient flow are: impeller damage, insufficient speed, high lift, blockage of debris in the pipe, etc.

5. The magnetic pump cannot output liquid.

The magnetic pump can not output liquid, which is a common fault of the pump. Check whether the air in the suction pipe is discharged, whether the liquid injected into the magnetic pump is sufficient, whether the suction pipe is blocked by sundries, whether the pump reverses (especially after replacing the motor or repairing the power supply circuit), remove the pump to check whether the pump shaft is broken, and check the moving ring of the pump. Check whether the stationary ring is intact and whether the carbon bearing is closely connected with the pump shaft.
prevent of water ring vacuum pump explosion to methods

1、 Maintenance method of packing seal

1. Clean the stuffing box of the sewage pump and check the shaft surface for scratches, burrs, etc. The stuffing box shall be cleaned and the shaft surface shall be smooth.

2. Check the shaft runout. The unbalance of the rotor runout should be within the allowable range to avoid excessive vibration, which is harmful to the packing.

3. Apply sealant or lubricant suitable for the medium to the stuffing box and shaft surface.

4. For the packing packed in rolls, first take a wooden stick with the same size as the journal, wind the packing on it, and then cut it with a knife. The knife edge is 45 ° inclined.

5. Fillers shall be filled one by one, not several at a time. The method is to take a piece of packing, apply lubricant, hold one end of the packing interface with both hands, pull it away along the axial direction to make it spiral, and then put it into the journal from the incision casing. It shall not be pulled apart along the radial direction to avoid uneven interfaces.

6. Take a metal shaft sleeve with the same size and material as the packing box or with lower hardness than the shaft, push the packing into the deep part of the box, and apply a certain pressure on the shaft sleeve with the gland to make the packing precompressed. The pre compression shrinkage is 5%~10%, up to 20%. Rotate the shaft for another circle and take out the shaft sleeve.

7. Fill the second and third root in the same way. Note that when the number of fillers is 4-8, the interfaces shall be staggered by 90 °; Two fillers are staggered 180 °; 3~6 pieces shall be staggered by 120 ° to prevent leakage through the interface.

8. After the packing is completed, the gland shall be used for compaction, but the compaction force shall not be too large. At the same time, rotate the shaft by hand to make the assembly pressing force tend to parabola distribution. Then loosen the gland slightly.

9. Carry out operation test. If it cannot be sealed, compress some packing; If the heat is too high, relax it. In this way, it can only be put into use when the leakage is in the form of drops and the heat is not too high (the temperature of the packing part can only be 30~40 ℃ higher than the ambient temperature).

Technical requirements for packing seal assembly of centrifugal pump. The installation of packing seals shall comply with the provisions of the technical documents. If not specified, the following requirements shall be met:

1. Check the radial runout of the shaft at the sealing parts, and the allowable radial runout of the shaft is within 0.03~0.08mm;

2. The diameter clearance between the liquid seal ring and the shaft sleeve is generally 1.00~1.50mm, and the diameter clearance between the liquid seal ring and the stuffing box is generally 0.15~0.20mm;

3. The diameter clearance between the packing gland and the shaft sleeve is generally 0.75~1.00mm, and the clearance around shall be uniform;

4. The diameter clearance between the packing gland and the stuffing box is generally 0.10~0.30mm;

5. When there is a packing bottom ring, the diameter clearance between the bottom ring and the shaft sleeve is generally 0.70~1.00mm;

6. After the packing is compressed, the liquid inlet hole of the liquid seal ring shall be aligned with the liquid seal pipe, or the liquid seal ring is slightly inclined to the outside;

7. For the packing in rolls, first take a wooden stick with the same size as the shaft, wind the packing on it, and then cut it with a knife. The cut is 45 ° inclined.
Why the vacuum unit leaks water

The corrosion resistant self-priming pump body is superior to the all plastic self-priming pump in thermal deformation resistance, stress damage resistance caused by thermal expansion and contraction of pipelines, installation reliability and vibration resistance. In the field of self-priming pumps, the sales volume of corrosion resistant self-priming pumps has always been high. So where does this equipment stand on its own? If you want to know this problem, let's first understand its characteristics.

What are the characteristics of corrosion resistant self-priming pump

1. Corrosion resistant self-priming pump is a centrifugal pump with high efficiency and corrosion resistance. With its compact structure, convenient operation, stable operation, convenient maintenance, long service life and other characteristics, it has always been the leader in similar products.

2. It is not only applicable to a wide range of fields, but also affordable and acceptable to many enterprises.

3. The corrosion resistant self-priming pump also has a very strong sewage discharge capacity. With the special internal structure design, the water-saving function is also reflected to the extreme. The self-priming height of this self-priming pump can reach 1 meter, and the self-priming time is also very short.

Corrosion resistant self-priming pumps are found in these places

The most common areas are tea gardens, nursery gardens, large orchards, farms, etc. These places cover a large area, and his help is needed for irrigation, fertilization, pesticide farming and other work. In addition to effectively improving work efficiency, it can also effectively save the cost of raw materials. On the basis of rain and dew, it greatly saves the cost of labor. No wonder there are corrosion resistant self-priming pumps in these places. Of course, in order to achieve such efficiency, the assistance of a rocker nozzle is also needed, so that small raindrops or spray like liquid can appear.
Molecular Pump Operation for Influence of Magnetic Field Environment

Fluoroplastic self-priming pump

Fluoroplastic self-priming pump adopts metal shell lined with fluoroplastics, all flow passage parts are made of fluoroplastics alloy, pump cover, impeller, etc. are made of metal inserts wrapped with fluoroplastics by overall sintering and pressing, shaft seal adopts external advanced corrugated pipe mechanical seal, static ring adopts 99.9% aluminum oxide ceramic (or silicon nitride), and dynamic ring adopts tetrafluoroplastics filling material, with excellent corrosion resistance, wear resistance and sealing performance. The inlet and outlet of the pump are reinforced with cast steel body to enhance the pressure resistance of the pump. The actual use shows that the pump has the advantages of corrosion resistance, wear resistance, high temperature resistance, non aging, high mechanical strength, stable operation, advanced and reasonable structure, strict and reliable sealing performance, convenient disassembly and maintenance, and long service life.

The outstanding feature of FZB self-priming pump is its self-priming function. It can pump the liquid below the installation position of the pump, with stable performance and simple operation. You only need to fill the liquid before the first use of the pump, and do not need to fill the liquid after the second and subsequent use. You can start the pump directly. The self-priming height can be determined within 2 to 4 meters according to the density of the medium. It is the choice to replace the bulky submerged pump.

2、 Main purpose:

The flow passage components of FZB fluoroplastic self-priming pump are all made of fluoroplastic and have self-priming function. Therefore, FZB self-priming pump has a wide range of applications, such as pumping corrosive liquid in the underground tank to the target location, pumping the acid and alkali in the acid and alkali tank with no outlet at the bottom to the target location, or for circulation between multiple acid tanks, or for acid unloading, etc.
why sk vacuum pump can inject oil of detailed explanation

1. Since the cooling and lubrication of the magnetic pump bearing depend on the conveyed medium, it is prohibited to run without load, and avoid the time and space load running caused by restart after power failure during work.

2. If the conveyed medium contains solid particles, a filter screen shall be added at the pump inlet; if it contains ferromagnetic particles, a magnetic filter shall be added.

3. The ambient temperature of the pump in use shall be less than 40 ℃, and the temperature rise of the motor shall not exceed 75 ℃.

4. The conveyed medium and its temperature shall be within the allowable range of pump materials. The service temperature of engineering plastic pump is less than 60 ℃, and that of metal pump is less than 100 ℃.

Convey liquid without hard particles and fibers with suction pressure no more than 0.2MPa, large working pressure 1.6MPa, density no more than 1600Kg ／ m3 and viscosity no more than 30X10-6m2 ／ S.

5. If the delivery liquid is a medium easy to precipitate and crystallize, it should be cleaned in time after use and the accumulated liquid in the pump should be drained.

6. After the magnetic pump operates normally for 1000 hours, the bearing and end face moving ring shall be disassembled and inspected for wear, and the wearing parts that are not suitable for reuse shall be replaced.
What about vacuum pump oil emulsification?

The pipeline centrifugal pump is used to transport clean water and other liquids with physical and chemical properties similar to clean water. It is suitable for industrial and urban water supply and drainage, pressurized water supply for high-rise buildings, garden sprinkler irrigation, fire pressurization, long-distance transmission, HVAC refrigeration cycle, bathroom and other cold and warm water cycle pressurization, and the inlet and outlet of the equipment supporting pipeline pump are the same size and the center is the same height from the ground, Many people may mistakenly think that the installation of the pipeline pump does not need to determine the direction, which is wrong. If the direction is wrong, the pressure will not go up or the water pressure will not be enough. Here is how to identify the direction of the inlet and outlet of the pipeline pump:

1、 Generally, pipeline pumps are marked. The arrow on the pump body or base points to the outlet of the pipeline pump, and the rest is the water inlet.

2、 Observe the structure, the closer to the base is the water inlet, as shown in the figure below, the closer to the base is the right direction, which is the water inlet. The water enters the water inlet, is sucked in by the impeller (2 points), and then is thrown out to the water outlet to enter the pipeline.

3、 Generally, the outlet of the pipe pump has a copper exhaust valve, which is used to exhaust or install other sensors. The one with this component is the outlet. If you still can't tell, please contact us for technical support.
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Treatment of eccentric reducer at inlet of corrosion resistant centrifugal pump

With regard to the installation of eccentric reducer on the inlet pipe of the end suction centrifugal pump (i.e. the pump inlet is a horizontal inlet), in the textbooks related to the pump piping standards, it is stipulated that the diameter orientation of the eccentric reducer on the horizontal pipe (the horizontal part is upward or downward) is determined according to the absence of a liquid bag or air bag (in two cases):

1. When the medium is fed into the pump from the top to the bottom, the bottom flat eccentric reducer is used for installation, and there is no liquid bag;

2. When the medium is fed into the pump from bottom to top, the top flat eccentric reducer is used for installation, without air bag;

Generally speaking, it is "flat at the top and flat at the bottom" To find out the reason, first understand one knowledge point: cavitation phenomenon. Of course, if you only do industrial installation, you don't need to know so much, because there are complete and correct installation methods in the instructions of each pump manufacturer, just follow the drawings

1、 Cavitation phenomenon

Working principle of centrifugal pump: the driver drives the impeller to rotate through the pump shaft to generate centrifugal force. Under the effect of centrifugal force, the liquid is thrown to the impeller outlet along the blade flow path, and the liquid is collected by the volute and sent to the discharge pipe. The liquid gets energy from the impeller to increase both the pressure energy and the velocity energy, and the liquid is transported to the work site by this energy. When the liquid is thrown to the impeller outlet, a low pressure is formed at the center of the impeller inlet, which creates a pressure difference between the liquid in the suction tank and the impeller center. Under the effect of this pressure difference, the liquid in the suction tank continuously enters the impeller through the suction pipeline and the suction chamber of the pump.

According to the working principle of the centrifugal pump, the liquid flows into the impeller under the pressure difference (Pa Pk) formed between the suction tank pressure Pa and the low pressure Pk at the impeller inlet. The lower the pressure Pk at the impeller inlet, the greater the suction capacity. However, if Pk decreases to a certain limit value (at present, the saturated steam pressure Pt of liquid at the transportation temperature is the critical value of liquid vaporization pressure), cavitation will occur.

2、 The methods to improve the cavitation resistance of centrifugal pump are:

A. Improve pump structure and reduce Δ Hr, belongs to the pump design problem.

B. To improve the effective NPSH in the device: the main common method is to use the injection head suction device.

In addition, the resistance loss of suction pipeline shall be reduced as much as possible, and the saturated vapor pressure of liquid shall be reduced, that is, the suction pipeline shall be designed with larger pipe diameter, shorter length, fewer elbows and valves, and lower temperature of liquid delivery, which can improve the effective cavitation allowance of the device.

Well, after understanding the above knowledge, let's have a look. What is the role of the reducer? It is used to change the size of pipe diameter. So what's the use of changing the pipe diameter at the pump inlet and outlet? It is mainly used to reduce the flow velocity of the medium in the pipeline, so as to reduce the friction force when the medium flows in the pipeline.

3、 Serious consequences caused by cavitation:

(1) Generates vibration and noise.

(2) The working performance of the pump is affected: when the cavitation develops to a certain extent, a large number of bubbles will be generated, which will block the flow passage, making the flow, head, efficiency, etc. of the pump drop significantly.

(3) The material of the runner will be damaged, mainly due to the fatigue erosion of the metal near the blade inlet.

The horizontal eccentric reducer at the inlet of the centrifugal pump generally adopts the top flat layout, but when the reducer is directly connected with the upward curved elbow, the bottom flat layout can be adopted. The reducer shall be close to the pump inlet. The reason for flat top installation is to prevent gas from accumulating in the eccentric reducer and entering the centrifugal pump to cause cavitation damage to the pump. When the inlet diameter of the horizontal suction centrifugal pump is changed, the top flat installation is adopted for the pipeline to enter the pump from bottom to top, and the bottom flat installation is adopted for the pipeline to enter the pump from top to bottom (the top flat installation is also adopted to prevent the gas from accumulating at the pump inlet). The bottom flat installation is adopted for the medium with impurities and the suction speed is lower than the impurity settlement speed. The principle is not to form air bags.
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Treatment Measures and Effects of Stainless Steel Magnetic Pump

1) Select appropriate bearing materials. All friction pairs at the bearing are made of high-quality silicon carbide. High quality silicon carbide has high purity,

Silicon carbide content is more than 99%, resistant to ammonia corrosion, with high strength, elasticity, toughness and wear resistance, which greatly improves the anti extrusion and impact capacity of the bearing, and its service life is more than 10 times that of other sliding bearings (such as graphite).

2) Select proper thrust bearing clearance when installing the rotor. By trial installing the rotor on the bearing body and pushing the rotor to one side, the maximum clearance between the industrial bearing toilet parts of the magnetic pump can be measured (when the bearing is normal, the maximum axial displacement j generated by the rotor is between 0.13-0.15, which is adjusted to 0.3-0.5 mm. This clearance range is conducive to the formation of the liquid film between the gaps, reducing the friction between the two friction pairs of the thrust bearing, and reducing the impact force when being impacted

3) Optimize operation in process to minimize or avoid large fluctuation of working conditions; The pump reversing period shall be extended to 2 months to minimize the adverse effects of frequent pump reversing on the magnetic pump.

4) The improved magnetic pump pays attention to the process operation during operation, showing the inherent characteristics of the magnetic pump. At the same time, it has good operation performance, free of maintenance for a long time, reliable operation, and a maintenance cycle of about one year, which ensures the long-term operation of the equipment.
water ring vacuum pump of phenomenon to be avoided in maintenance

simple machine. During maintenance, we should pay attention to the use within the rated range, and we should not operate with no load. We should pay attention to avoid cavitation and steam binding. We should strengthen inspection and replace the worn sealing parts in time.

The following are the maintenance steps summarized by the water pump plant based on years of experience:

1. Check whether the pipes and joints of the clean water centrifugal pump are loose. Rotate the clean water centrifugal pump by hand to see whether the pump is flexible;

2. Add bearing lubricating oil into the bearing body, observe that the oil level should be at the center line of the oil pointer, and the lubricating oil should be replaced or replenished in time;

3. Unscrew the water diversion screw plug of the pump body of the clean water centrifugal pump and inject water;

4. Close the gate valve and outlet pressure gauge of the outlet pipe;

5. Inch the motor and Wuxi welded pipe to see if the rotation direction of the motor is correct;

6. Start the motor. When the clean water centrifugal pump is in normal operation, open the outlet pressure gauge and gradually open the gate valve, and check the motor load;

7. Try to control the flow and lift of the clean water centrifugal pump within the range indicated on the label. Xinxiang Pump Plant can obtain very good energy saving effect by ensuring that the centrifugal pump operates at a higher efficiency point;

8. During the operation of the clean water centrifugal pump in Xinxiang Pump Plant, the bearing temperature shall not exceed the ambient temperature by 35 ℃, and the higher temperature shall not exceed 80 ℃;

9. If any abnormal sound is found in the clean water centrifugal pump, stop the pump immediately to check the cause;

10. When the clean water centrifugal pump is to be stopped, first close the gate valve and pressure gauge, and then stop the motor;

11. The lubricating oil of the clean water centrifugal pump shall be changed every 500 hours after 100 hours within one month of operation;

12. Regularly adjust the packing gland to ensure that the leakage in the packing chamber is normal;

13. Regularly check the wear condition of the shaft sleeve, and timely replace it if it is worn seriously;

14. When the clean water centrifugal pump is used in cold winter, the drain plug at the lower part of the pump body shall be unscrewed after shutdown to drain the medium to prevent frost cracking;

15. If the clean water centrifugal pump has been out of service for a long time, it is necessary to disassemble all the pumps, wipe off the water, coat the rotating parts and joints with grease, and store them properly.
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Need to know for selection of vertical centrifugal pump

As we all know, the vertical centrifugal pump is used to transport clean water and other basic liquids with physical and chemical properties similar to clean water. It is suitable for industrial and urban water supply and drainage, pressurized water supply for high-rise buildings, garden sprinkler irrigation, fire pressurization, long-distance transmission, and HVAC refrigeration cycle. So the use of different industries is not completely the same, so we can not choose the same product when we choose vertical centrifugal pump, so how do we choose vertical centrifugal pump reasonably?

Reasonable pump selection requires comprehensive consideration of comprehensive technical and economic indicators such as pump unit, pump station investment and operation cost, so as to conform to the principles of economy, safety and applicability. It includes the following aspects:

1) Water pumps with high efficiency, low noise and energy conservation shall be selected, and obsolete products are strictly prohibited.

2) . The pump shall be selected according to the design flow and the required lift, and considering that the pump output decreases due to wear and other reasons, the pump can be selected by multiplying the calculated lift H by a coefficient of 1.05~1.10; The pump with the characteristic curve of gradually decreasing head as the flow increases shall be selected, so that the pump can work stably and reliably in parallel; And the operating point of the water pump should be kept in the high efficiency range, which is not only energy-saving but also not easy to damage the parts.

3) When there is no regulating facility in the water supply network, it is better to use the speed regulating pump set or the rated speed pump set for marshalling operation of water supply. The maximum water output of the pump unit shall not be less than the design water supply flow of the community, and shall be checked according to the fire fighting conditions.

4) . The number of lifting pumps for water tank and water tower shall be reduced as far as possible, and one for use and one for standby; When a single pump can meet the requirements, it is not suitable to use multiple parallel pumps; If multiple pumps must be operated in parallel or matched with large and small pumps, their models and numbers should not be too many. Generally, they should not exceed two types, and the lift range of pumps should be similar; When running in parallel, each pump should still operate within the high efficiency zone.

5) The design water supply flow of the variable frequency speed regulating pump (group) shall meet the requirements of the maximum design flow per second in the domestic water supply system. The power supply must be reliable (dual power supply or dual circuit power supply); The working point of the pump shall be selected in the efficient working area of the pump characteristic curve (Q-H curve), and not in the extension line of the Q-H curve. The most unfavorable working point shall be designed at the right end of the efficient section of the pump characteristic curve, that is, the point where the pump has the largest water output, but the head is low but can meet the requirements, that is, the intersection point between the low point of the efficient section of the pump characteristic curve and the pipe characteristic curve. The working range of water pump speed regulation shall be within the high efficiency range of water pump as far as possible; The speed regulation range should be set between 25% and 100% of the water supply of the pump; The equipment shall have automatic water level control function.

6) The water pump unit of the domestic pressurized water supply system shall be equipped with a standby pump. The water supply capacity of the standby pump shall be greater than the water supply capacity of the largest operating pump. The pump shall be automatically switched and operated alternately.

7) The voltage of the motor equipped with the water pump shall be the same, and the power supply system shall be the same as that of the national grid.
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Disassembly and assembly steps of horizontal clean water centrifugal pump

The centrifugal pump needs to pay attention to maintenance, which requires the operator to be very familiar with the water centrifugal pump, not only to have rich maintenance experience, but also to understand the working principle, disassembly, maintenance, installation, etc. of the centrifugal pump. The following is the removal and installation procedure of horizontal water centrifugal pump.

Disassembly and assembly steps of horizontal clean water centrifugal pump:

Before the installation of horizontal centrifugal pump, first check whether the parts are bumped and worn, clean them, and then assemble them.

(1) First, tighten the connecting bolts and plugs on the corresponding parts.

(2) Place the O-ring, paper pad, felt, etc. on the corresponding parts.

(3) First, install the seal ring, packing ring, packing ring, packing gland, etc. into the pump cover in turn.

(4) Install the rolling bearing on the shaft and then on the suspension, close the gland, press down the rolling bearing, and sleeve the connecting bolt on the shaft.

(5) Install the shaft sleeve on the shaft, and then install the pump cover on the suspension. Install and tighten the impeller, stop washer, impeller nut, etc. Then assemble the above accessories into the pump, and tighten the connecting bolts on the pump body and pump cover.

In the above installation process, the components that are easy to be ignored, such as O-ring, flat key and water retaining ring, can be put into the sealing bag.

From step (5) to step (1), the disassembly sequence of the horizontal clean water centrifugal pump can be reversed.
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Centrifugal pumps are commonly used in the chemical industry. Fluoroplastics centrifugal pump seals include mechanical seals and double end water circulation seals. Self flushing uses the medium conveyed by the pump itself to enter the seal chamber through the small hole on the end face seal gland. Mixing with the medium in the pump is called self flushing. Self flushing pump can be used. The medium delivered is generally low temperature (<100 ℃) and clean, usually light oil or water. A common explanation is that the pump self flushing cannot be used for the liquid with high temperature and viscosity, because such liquid will damage the pump when entering the pump, and the viscosity will make it difficult for the liquid to enter the pump.

Self flushing means that a thin pipeline is led from the pump outlet to the pump chamber after passing through the sealing surface or to the inlet through piping, or a pumping ring (such as a small impeller) is set in the sealing chamber to circulate the sealing liquid, which is used to warm the clean liquid that is below 80 ℃ and does not contain particles; For the flushing liquid with high temperature, it can be added to the cooler and enter the sealing surface after cooling. For the liquid containing particles, it can be added to the filter to remove the particles and then enter the sealing surface.

There are generally four self flushing functions:

1、 Flushing function, flushing impurities between the friction between the moving ring and the stationary ring;

2、 For lubrication, a layer of liquid film is kept between the sealing faces for lubrication;

3、 Cooling effect: take away the heat generated by friction between moving ring and stationary ring during working time, reduce the temperature of sealing elements, and extend the service life of seals;

4、 Sealing function: prevent the air outside the pump from leaking into the pump to play a sealing role.
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What are the working principles of gear pump

Gear pump is one of the most widely used rotor pumps in the coating industry. According to different gear meshing modes, gear pumps can be divided into external gear pumps and internal gear pumps. External gear pumps are widely used, and generally referred to as gear pumps.

The working principle of the gear pump: 1. The gear pump delivers liquid by relying on the volume change of the working space caused by the meshing process of the gears.

Working principle II of gear pump: the working space is composed of the pump body, pump cover and the grooves between the teeth of the gear, and the meshing gear teeth divide this space into the suction chamber and the discharge chamber. When a pair of gears rotate, the gear teeth located in the suction chamber gradually withdraw from engagement, so that the volume of the suction chamber gradually increases and the pressure decreases. The liquid enters the suction chamber along the suction pipe until it fills the entire tooth space.

Working principle of gear pump 3. With the rotation of the gear, the liquid entering the teeth is brought to the discharge chamber. At this time, the gear teeth enter the mesh, occupying the volume between the teeth, so that the volume of the discharge chamber becomes smaller, and the liquid is forcibly discharged. When the gear pump is running, the liquid sucked in is full of the slots.

Working principle of gear pump 4. As the gear rotates, the liquid is transported to the high-pressure area along the shell wall. Because the two gears mesh with each other, the liquid in the gear slot at the meshing point is squeezed out and discharged into the outlet pipeline. At this time, a negative pressure area is formed in the enclosed space, and the liquid at the pump inlet is pressed to the pump suction under the action of atmospheric pressure.

Working principle of gear pump V. The discharge pressure of gear pump is high, the volume is small, and the flow is not large. In paint production, it is generally used to transport solvent, oil, paint and paint slurry.
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Technical innovation of motor-driven fire pump

Motor driven fire pump is a kind of fire pump which is directly connected with light engine and water pump and can be moved or fixed by manpower to put out general material fire and small oil fire. Due to the advantages of portability, flexibility and freedom from traffic, power and regional barriers, the motor driven pump has been widely used to put out the initial fire in places with poor road access conditions, such as industrial and mining enterprises, warehouses, ports, docks and rural areas, where it is difficult for fire engines to pass or reach in time.

Motor driven fire pump is mainly composed of engine, water supply system and fixed support. At present, the water inlet of the fire pump used at home and abroad is hard tubular (determined by the operating principle of the equipment), and the screw thread rotary sleeve method is generally used between the water inlet of the pump body and the water intake pipe. The main problems of this method are as follows: the user must insert the threaded joint of the water intake pipe into the threaded pipe orifice at the other end of the water pump inlet in a parallel rotation way, which is hard and time-consuming; In addition, when the water inlet pipe is aging and hard, especially in winter, it is difficult to quickly install the water inlet pipe. In case of fire, it will bring great trouble to users. In case of fire alarm, fire fighting is against time, so the application of this technology greatly reduces the difficulty of operation and improves the actual application performance of the product.

Zhejiang Yu'an improved the original product. After the improvement, the products were compared. The specific parameters (of the same group of operators) are as follows: the water filling time of the fire pump before the improvement is 110 seconds; The water filling time of the improved fire pump is 40 seconds.

So where is 70 seconds saved? 1. When the motor-driven fire pump is under vacuum, Yu'an adopts the one-way valve technology, which eliminates the need to manually close the connection switch for 6 seconds; 2. After Yu'an improved the connection between the water inlet and the water diversion pipe of the fire pump, the time required for the quick coupling connection method is 1 second; It took 65-95 seconds for the original thread mode; How long does it take for a fire to burn violently from the initial stage? Class A fire generally lasts about 5 minutes; Class BC fire generally lasts about 2 minutes; It can be seen that the application of this technology will greatly improve the fire extinguishing efficiency, effectively control the further upgrading of fire, and greatly improve the excellent performance of this product.
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Sewage lift pump has some characteristics

As a kind of water body that will inevitably be discharged in our life, sewage treatment is also essential. In the process of treatment, a kind of pump body needs to be used. This kind of pump body is sewage lift pump. This kind of pump mainly focuses on four parts. Some of them are pumps, some are motors, and some are topics and control systems. In terms of application, it is also very extensive. It is mainly used in families, Besu and some small and medium-sized business places. Whether on the ground or under the liquid, such pumps can work accordingly.

The main function of sewage lift pump is to discharge sewage. Therefore, it depends on the performance of such products, mainly on your pollution discharge capacity. It adopts single or double impeller structure, which can greatly improve the entire sewage discharge capacity. The whole pump body is compact in structure and very small in volume. This feature can ensure that the pump body has a very good carrying capacity. Not only that, but also the noise it produces is very small. In the process of work, it has a high power saving function. In any case, it is quite convenient to check. As long as it is in the water environment, it can work. In this way, a lot of project cost can be saved in the process of construction.

The sewage lift pump is also equipped with a float switch, which can change according to the change of liquid. Automatically control the start or stop of the pump body. For this type of pump, it does not require special personnel to take care of it, and it is quite convenient in the process of use. It is very convenient not only in the process of use, but also in the process of installation and maintenance. This is also the reason why such pumps are widely used.

Sewage lift pump is very popular in our life. If you want to buy this kind of pump, but don't know how to choose it, you might as well choose Chongqing Zhongbai Pump Industry Co., Ltd. This company has many years of technology in the production and manufacturing of pump bodies. The produced pump body is not only of good quality, but also of high cost performance. It will provide you with pumps of different models, varieties and prices. No matter what kind of pump you want. They can be provided to you.
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How to avoid reverse flow of wear-resistant centrifugal pump?

In fact, the operation process of wear-resistant centrifugal pump is not very complicated, but it only needs to be used correctly. Even with the help of instructions or professionals, there will always be some problems that they cannot help. This requires us to constantly understand new content and solve new problems in the process of use, so as to better use the equipment.

The centrifugal pump can only discharge water when it is above 30-35Hz, because the higher head of the pump's performance curve must be greater than the net head of the pump, or the working head of the wear-resistant centrifugal pump running in parallel, and this frequency corresponds to the lower frequency of the variable frequency operation of the pump.

When the frequency is below very low frequency, the wear-resistant centrifugal pump does not produce water and has no effective power output. Its loss is only the no-load loss of the pump. Therefore, the current and power of the motor are very small. At this time, the efficiency of the pump drops to a lower value.

Once the operating frequency is higher than the lower frequency, the flow of the wear-resistant centrifugal pump after water discharge must overcome the resistance of the pipe network on the one hand and the net head on the other. Therefore, the pump power and motor current increase significantly, with a sudden jump, and then continue to increase with the increase of frequency.

Since the variable frequency pump always has a flow, there is no phenomenon that the flow of the power frequency pump flows back to the variable frequency pump. In the actual project, the pipeline is also equipped with a check valve. If the frequency of the frequency converter is lower than a lower frequency, the variable frequency pump does not discharge water, and the check valve automatically closes to prevent water from flowing back.
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Flow regulation method of non clogging pulp pump

In practical work, in order to achieve ideal working efficiency, it is necessary to control and adjust the flow of the non clogging pulp pump. In order to achieve this goal, we must first understand the factors that affect the flow of the non clogging pulp pump.

Internal causes affecting the flow of non clogging pulp pump:

The outlet pipe is not unblocked or the impeller is blocked, the impeller falls off or is damaged, the bottom of the pump is severely worn or blocked by debris, the pipe impeller is blocked, the seal ring is damaged, the pressure is insufficient, or the rotation speed of the non blocked pulp pump is too slow.

External factors affecting the flow of non clogging pulp pump:

The installation height of the non clogging pulp pump is too high (the impeller is too close to the horizontal plane), the density or viscosity of the liquid medium conveyed by the non clogging pulp pump is too high, and the working head of the non clogging pulp pump is too high.

Flow regulation method of non clogging pulp pump:

1. Throttle regulation. For the pump unit with gate valve installed in the outlet pipeline, if the gate valve is closed for a short time, the local resistance in the pipeline will increase, the pipeline characteristic curve will become steeper, and its working point will move to the top and move to the left along the QH curve of the pump. The smaller the gate valve is closed, the greater the resistance and the smaller the flow rate.

2. Speed change adjustment. By changing the speed of the motor of the non clogging pulp pump, the performance of the pump and the operating point of the pump are changed, so as to achieve the purpose of regulating the flow of the non clogging pulp pump.

3. Reducing adjustment. After the impeller is turned, the performance of the water pump will change according to certain rules, thus changing the working point of the water pump.

4. Variable angle adjustment. By changing the installation angle of the blade, the performance of the pump and the working point of the non clogging pulp pump can be changed, so as to adjust the flow of the pump.
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Impeller Anti blocking Design of Self priming Sewage Pump

The anti blocking design of the impeller of the self-priming sewage pump ensures high efficiency and no blocking. Excellent hydraulic model is adopted, and the efficiency is 3~5% higher than that of general self-priming sewage pump. The self-priming height is 1m higher than the general self-priming sewage pump, and the self-priming time is shorter.

The self-priming sewage pump adopts the pump body structure of axial liquid return. The self-priming sewage pump body is composed of a suction chamber, a liquid storage chamber, a scroll chamber, a liquid return hole, a gas-liquid separation chamber, etc. after the self-priming sewage pump is normally started, the impeller sucks in the liquid stored in the suction chamber and the air in the suction pipe together, and is fully mixed in the impeller. Under the action of centrifugal force, the liquid entrains the gas to flow to the outer edge of the scroll chamber, forming a white foam belt with a certain thickness and a high-speed rotating liquid ring on the outer edge of the impeller. The gas-liquid mixture enters the gas separation chamber through the diffusion tube. At this time, due to the sudden decrease of the flow rate, the lighter gas is separated from the mixed liquid, and the gas continues to rise and discharge through the pump body outlet. The degassed liquid returns to the liquid storage chamber, enters the impeller again through the return hole, mixes with the gas inhaled from the suction pipe inside the impeller, and flows to the outer edge of the impeller under the action of the high-speed rotating impeller. As this process goes on repeatedly, the air in the suction pipe decreases continuously until the air is exhausted, and the self-priming sewage pump completes the self-priming process, and the self-priming sewage pump is put into normal operation.

The self-priming sewage pump is a sewage pump with a certain self-priming capacity, and its self-priming height is also limited. How to improve its self-priming height in product technology and how to improve its self-priming capacity during installation and use are the focus of our research and analysis.

The self-priming sewage pump is known as a vacuum pump product that can pump water. It combines the structural characteristics of the water ring vacuum pump and the self-priming sewage pump, which can quickly generate high negative pressure and transport high proportion of chemical media. It uses the impeller, pump body and cover plate to form a multi-channel sealing chamber for rapid exhaust. It takes only 2 seconds to fill water at a height of 3 meters, and 8 seconds to fill water at a height of 5 meters. Compared with ordinary self-priming sewage pumps, it greatly improves the efficiency and replaces traditional self-priming sewage pumps in many fields. The self-priming sewage pump produced by our company has a high suction lift, which is also known as the high suction lift self-priming sewage pump. The pump shaft and motor shaft are integrated, and have better stability. It is easier to use than the oil barrel pump in barrel loading and transportation. It can not only completely transport the media at the bottom of the barrel, but also directly switch between two barrels in one second. It can work continuously by making a multi way connector at the import. The actual use cost is lower than that of the oil barrel pump. Multiphase mixed conveying technology is a practical product in the field of conveying chemical media with high viscosity and high proportion, as well as in the food and beverage industry.

The general self-priming sewage pump does not need to install the bottom valve when the suction head is about 5 meters. If it is more than 5m, the suction head can be improved by adding a bottom valve at the end of the inlet, generally about 1m. The horizontal distance at the entrance and the number of elbows, especially the 90 degree angle and continuous turns, shall be minimized. Like centrifugation, irrigation and diversion can effectively shorten the self-priming time. Now the large flow self-priming sewage pump is equipped with a vacuum auxiliary device. Instead of irrigation and diversion, start the vacuum pump to exhaust, and the suction head is increased to more than 8 meters. The large-scale self-priming sewage pump produced by our company uses the latest semi open impeller and spiral impeller, which have good anti blocking ability and strong cutting function. The precision CNC machining technology allows the clearance between the impeller and the inner wall of the pump body to be as small as possible (the impeller of the cutting self-priming sewage pump is embedded in the mouth ring). The self-priming sewage pump with proper suction head can not only save cost but also meet the actual demand.
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The manufacturer tells you what the centrifugal pump pressure gauge has

Pressure is not a benchmark, but a derived force and area. Pressure gauge, also known as pressure gauge, is an industrial automatic instrument used to measure the pressure of gas or liquid. The pressure gauge of centrifugal pump can display and record the pressure value, and can also be attached with a control device. The pressure measured by the instrument includes: pressure, atmospheric pressure, positive pressure, negative pressure and differential pressure. Most engineering measurements are pressure gauges. The unit of pressure is Pa, and other units are: engineering air pressure, millimeter water column, etc.

The main principle of centrifugal pump pressure gauge measurement is as follows: use gravity and pressure balance, such as liquid column pressure gauge, piston pressure gauge measurement; The elastic pressure balance measurement method such as mechanical pressure gauge is adopted; Use pressure related pressure gauges to measure the pressure of other physical properties of substances, such as electronic pressure gauges.

Common liquid column pressure gauges include U-tube pressure gauge, single tube pressure gauge, inclined tube pressure gauge, etc. In practical application, there are many factors that will affect its accuracy, and some specific problems can be ignored - the main factors are environmental temperature change, gravity acceleration, capillarity, etc., which need to be corrected. In addition, it also affects the scale, reading and installation. Its advantages are convenient, simple, real and cheap. Commonly used in laboratories.

At present, commonly used mechanical pressure gauges include spring tube pressure gauge, diaphragm pressure gauge, bellows pressure gauge, etc. The elastic elements are spring tubes, diaphragms and bellows. Because the displacement caused by the deformation of the elastic element is very small, it is usually used as the angular displacement or electrical and pneumatic signals of the indicator for the convenience of display. It is simple, cheap and easy to use, and is widely used in industrial fields.

Installation and technical requirements for mechanical seal of centrifugal pump: technical requirements for machine, pump and mechanical seal accessories: the bending of shaft shall not exceed 0.05mm; All parts in the assembly meet the drawing requirements. When tightening the gland, after the coupling is aligned, tighten the compression screw to prevent the deflection of the flange face; The shaft vibration during mechanical seal installation shall not be greater than 0.1mm. The axial displacement of axis C shall not be greater than 0.5mm; The manufacturing tolerance of the shaft of the mechanical seal part is h8, and the finish is 1.6; The shaft end where the dynamic ring seal is installed and the gland end where the static ring seal is installed shall be chamfered; The installation of pump mechanical seal requires that the movable ring must be able to move flexibly on the shaft after installation.

The above is what the small editor of the centrifugal pump manufacturer told us about the centrifugal pump pressure gauge. I hope it can help you.
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Instructions for Use of Sealless Control Self priming Pump

New users will need to know some instructions when purchasing the unsealed automatic self-priming pump.

1. After the installation of the self-priming pump is completed, the discharged medium can be filled from the inlet as the initial drainage, and then no further drainage is required.

2. Please tighten the cap of the drain port, and the cap leaks, affecting the self suction effect.

3. The filter screen with buffer plate structure at the bottom of the liquid suction port can be installed to avoid damaging the self-priming pump due to excessive particle suction and affecting the self-priming function of the unsealed self-priming pump.

4. When pumping concentrated sulfuric acid, it is forbidden to use water as drainage to avoid personal and equipment failures.

5. Before starting, check whether the main shaft of the self-priming pump is flexible, which can be checked by inching, and the running direction should be consistent with the mark.

6. The weight of the suction and discharge pipes shall not be supported on the outlet flange of the self-priming pump, but shall be fixed on the support frame. The support frame shall be purchased by the user. All parts of the pipe connection shall be tight and air tight, otherwise the self-priming performance and flow head will be affected.

7. When pumping the liquid with crystals or sediments, if the pump is not used for a long time, the accumulated liquid in the pump should be drained to avoid crystals or sediments left in the pump, which may cause damage when the pump is started again.

8. If there is no crystal or sediment in the pump suction, if it is stopped for a long time for secondary use, you can check whether the liquid is sufficient from the drainage port. If not, it can be insufficient before self suction.

9. When pumping liquid, the flow, lift and suction head shall be strictly controlled within the specified range of the selected model. Otherwise, it will cause motor overcurrent fluctuation and affect operation.

10. If used in containers below the ground.

11. If the self-priming pump is used in an environment below the liquid level.

12. If liquid is supplied to high level tank or water tower.

13. When the medium with bubbles, high lift, large specific gravity and excessive static pressure of the water column in the outlet pipeline system is discharged, the exhaust speed can be accelerated and the self-priming time can be shortened.

14. In case of fire fighting system of water pressure pool, the water outlet time shall be shortened to a greater extent.

15. It is used instead of pipeline pump and closed circulating system.

16. The drainage outlet, overflow outlet, vent, self-priming exhaust device and outdoor cover are all independent of the system connection.

17. If it is designed to be used in an environment where the liquid outlet speed is required, the diameter of the suction pipe of the self-priming pump cannot be expanded, otherwise the liquid suction speed will be affected.
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Six Reasons for Head Reduction of Pipeline Pump

During the operation of the pipeline, some factors may reduce the head. The following are the six reasons.

1. Impeller passage blocked

The blockage of impeller flow passage will affect the work done by the impeller, and the pressure at the outlet will drop. This problem can be prevented by removing the pump body, removing foreign matters, and installing a filter device at the pump inlet.

2. Internal leakage occurs

The clearance between the rotating part and the stationary part of the pump body is too large, which exceeds the design index, and internal leakage will occur. The phenomenon is that the discharge pressure of the pump decreases, such as the clearance between the impeller ring and the interstage clearance of multistage pump. At this time, the corresponding inspection and replacement of components should be carried out.

3. Cavitation at inlet

When the inlet pressure of the pump is too low, lower than the saturated vapor pressure of the pumping ring, cavitation will occur. The solution is to check whether the inlet pipeline system is blocked, whether the opening of the inlet valve is too small, or increase the liquid level of the suction pool.

4. Speed decrease

The important factors for head reduction are the outer diameter of the impeller and the speed of the pump. Under the same conditions, the head is in direct proportion to the quadratic power of the speed, so the speed has a great impact on the head. Some reasons reduce the speed of the pump, which will affect the head. At this time, check the speed of the pump. If the speed is not enough, find out the cause and eliminate it.

5. The operating point is shifted to large flow and low lift

In most cases, the interest energy has a continuous rural performance curve, and the flow increases as the head decreases. In use, if there is some factor that causes the back pressure of the pump to decrease, the working point of the pump will shift to the point with large head and flow along with the device curve, which will cause the head to decrease. This is mainly caused by the change of external factors, and has nothing to do with the pump itself. It can be solved by increasing the pump back pressure.

6. Motor reverse

Improper wiring results in the motor steering contrary to the actual requirements of the pump. Normally, observe the rotation direction of the pump when starting. If it reverses, exchange any two wires of the terminal on the motor.
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Exhaust and water filling method of centrifugal pump

When the centrifugal pump is started, it will carry out the actual operation of exhaust and water filling, which can make the machine run more effectively. So next, I'll explain the water filling and exhaust methods of this machine in detail. Let's take a look.

Since the centrifugal pump generates vacuum pump and water seepage after the pressure in the pump is discharged by the centrifugal impeller, in addition to the centrifugal pump and the self suction pump with the centrifugal impeller immersed in water, it is generally necessary to fill the pump with water before starting the pump every time, which is also known as adding a diversion channel. There are two ways to fill water: one is to fill the pump immediately (at this time, the air outlet should be opened to drain the gas in the pump); The second is to pump out the steam in the pump, create a certain vacuum value (at this time, close the stop valve at the outlet), and introduce water resources.

1. Install gate valves at the inlet and outlet to fill water. This type of method is to install a gate valve at the water inlet, and then fill the pump with water after connecting the tap water pipe.

2. Fill water with hand pump. Some pumps have built-in hand pressure pumps, and small and medium-sized hand pressure pumps can also be purchased or made by ourselves. Stop valves must be installed on the inlet pipes. After closing the gate valve tightly, fill the water pressure machine with a small amount of water to carry out the diversion channel. After manually pressing the water output of the pump, it indicates that the pump is filled with water and can be started.

3. Exhaust and fill water with vacuum technology. The self exhaust of centrifugal pump is the same as the negative pressure exhaust of mechanical pump, so the water ring mechanical pump exhaust can fill the water channel.

Therefore, when the centrifugal pump cannot perform the actual operation of exhaust and water filling normally, it must be repaired immediately to prevent endangering all normal applications of machinery and equipment, or it will continue to cause damage to machinery and equipment at a certain level.
Calibration method of Vacuum Leak

Features of sealless self-priming pump

We usually have WFB type and other types of sealless Self-priming pumps. This sealless self-priming pump is a very popular type of pump and valve products today, because it has very unique advantages. The following are the main characteristics:

1. The sealless self-priming pump produced by our company adopts the "ring-shaped multi-sided centrifugal sealing device for pump", which eliminates the packing seal, packing seal and mechanical seal of the traditional water pump, and completely overcomes the "running, emitting, dripping and leaking". It is the most ideal equipment to replace various long shaft underwater pumps and submersible pumps.

2. It has superior automatic control function and can be used in combination with high-tech fields and highly automated systems.

3. During operation, the sealing device is free of friction and damage, and its service life is more than 10 times longer than that of similar products.

4. Small vibration, low noise, flexible movement, easy disassembly, easy installation, no need for anchor fixation.

5. Transplanting the principle of vacuum pump, the self-priming performance is stable and reliable. In particular, the "electric air control valve" truly realizes "one drainage, life-long self-priming".
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Usage and advantages of sewage pump in the project

The submersible sewage pump is a kind of pump product which is connected with the motor and works underwater at the same time. Compared with the general horizontal pump or vertical sewage pump, the submersible sewage pump has the following advantages:

1. Compact structure and small floor area. Since the submersible sewage pump works underwater, it can be directly installed in the sewage tank without building a special pump house to install pumps and machines, which can save a lot of land and infrastructure costs.

2. Easy installation and maintenance. Small submersible sewage pumps can be installed freely, and large submersible sewage pumps are generally equipped with automatic coupling devices for automatic installation, which is quite convenient for installation and maintenance.

3. Long continuous operation time. Because the pump and motor are coaxial, the shaft is short, and the rotating parts are light, the load (radial) borne by the bearing is relatively small, and the service life of the submersible sewage pump is much longer than that of the general pump.

4. There is no cavitation damage, irrigation and water diversion. In particular, the latter point brings great convenience to operators.

5. Low vibration and noise, low motor temperature rise, no pollution to the environment.

It is precisely because of the above advantages that submersible sewage pumps have been paid more and more attention by people, and the scope of use has become wider and wider. From the original simple use of conveying clean water to the present, they can convey all kinds of domestic sewage, industrial wastewater, construction site drainage, liquid feed and so on.

It plays a very important role in municipal engineering, industry, hospital, construction, hotel, water conservancy construction and other industries.

However, everything is divided into two, and the most critical issue for the submersible sewage pump is the availability, because the submersible sewage pump is used underwater; The medium to be conveyed is some mixed liquids containing solid materials; The pump is close to the motor; The pump is arranged vertically, and the weight of rotating parts and the water pressure borne by the impeller are in the same direction. These problems make the requirements of submersible sewage pump in sealing, motor bearing capacity, bearing arrangement and selection higher than those of ordinary sewage pumps.

In order to improve the service life of the submersible sewage pump, most manufacturers at home and abroad are now trying to find ways to protect the pump, that is, when the pump has leakage, overload, overtemperature and other faults, it can automatically alarm and automatically stop for repair. However, we believe that it is necessary to set up a protection system in the submersible sewage pump, which can effectively protect the safe operation of the electric pump.

However, this is not the key to the problem. The protection system is only a remedy after the pump fails, which is a more passive method. The key to the problem should be to start from the root and completely solve the problems of sealing and overload of the pump, which is a more active way. Therefore, we apply the hydrodynamic sealing technology of the auxiliary impeller and the non overload design technology of the pump to the submersible sewage pump, which greatly improves the sealing reliability and bearing capacity of the pump and extends the service life of the pump.
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Self priming sewage pump with strong sewage discharge capacity

The self-priming sewage pump integrates self-priming and non clogging sewage discharge. It adopts the axial reflux external mixing type. Through the unique design of the pump body and impeller flow passage, it can not only suck and discharge the liquid containing large particle solids and long fiber impurities without installing the bottom valve and filling water as the general self-priming clean water pump, but also can be widely used in municipal sewage projects, river pond aquaculture, light industry, paper making, textile, food, chemical industry, electricity, fiber The most ideal impurity pump for chemical media such as slurry and mixed suspension.

Advantages of self-priming sewage pump:

1. Strong sewage discharge capacity: the special impeller anti blocking design ensures that the pump is efficient and free of blockage.

2. High efficiency and energy saving: excellent hydraulic model is adopted, and the efficiency is 3-5% higher than that of general self-priming pump.

3. Good self-priming performance: the self-priming height is 1m higher than the general self-priming pump, and the self-priming time is shorter.

Application scope of self-priming pump:

1. Used for handling non flammable and explosive liquids;

2. Rainwater and general sewage;

3. Municipal sewage project, construction site, civil air defense system drainage station;

4. Industrial wastewater from light industry, paper making, textile, food, chemical industry, power industry, mining and other industries;

5. Sewage discharge in residential area;

6. Sewage and sediment of water purification system;

7. Leather industry, slaughterhouse sewage and pond aquaculture; Wine making and sugar industry;

8. Discharge sewage that is not highly corrosive but has been seriously polluted.

The self-priming sewage pump is suitable for conveying industrial water and urban domestic sewage. Its greatest advantage is that it can convey sewage containing solid particles and fiber materials. It integrates self-priming and non clogging sewage discharge. It not only does not need to install bottom valves and lead water like the general clean water self-priming pump, but also can pump the dirt, sediment, waste ore impurities, feces treatment and all engineering sewage containing large particle solid blocks and long fibers. It completely reduces the labor intensity of workers, and is easy to move and use, install, with little maintenance and stable performance.
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Introduction to adverse effects of idling of magnetic pump

The damage to the air and the cost of the magnetic pump will be great. The idling of the magnetic pump causes damage to many components, one pump body, inner magnetic steel, outer magnetic steel, stationary ring, impeller, isolation sleeve, pump shaft, thrust ring, seal ring, etc. In the process of using the magnetic pump, idling is the cause of many failures, so users must understand that the magnetic pump is not idle. Next, Xiaobian briefly explains why the magnetic pump is not allowed to idle. The main reasons are as follows:

1. The magnetic pump cannot idle, because the magnetic pump of the magnetic cylinder is composed of cooling medium, and air will cause the magnetic cylinder to lock.

2. Most of the bearings of the rotor of the magnetic pump are made of cemented carbide and lubricated by the medium. The pump cannot be lubricated.

3. After the pump is empty, there is no material to cool the pump, so it is possible to directly burn the diaphragm.

4. The core components of the magnetic pump are the outer magnetic component and the inner magnetic component. If it idles, the core components will be demagnetized at high temperatures and the performance of the magnetic pump will be greatly reduced after demagnetization.

Magnetic pump

In addition, in order to ensure the stability of the magnetic pump, regular maintenance of the equipment is also a way to reduce the failure rate of the equipment, including:

1. The front end of the magnetic pump shaft is equipped with a stuffing box with reliable sealing function. At the same time, a mechanical seal device is installed on the bearing seat, so that a large amount of leakage will not occur and a small amount of leakage will be discharged through the leakage port. It is normal to have a small amount of leakage at the beginning of the start-up operation. After the sealing surface is operated for a certain period of time, the leakage will be reduced or stopped.

2. There are two ball bearing pedestals, which lubricate one ball bearing on the pump impeller side of the magnetic pump with the transmitted heat-transfer oil, and one ball bearing on the coupling side is lubricated with high-temperature grease: each ball bearing must be disassembled after 3000 hours of operation to clean the diesel engine for inspection. If the contact surface is damaged, it must be replaced with a new one. When the ball bearing is installed on the impeller side, the side of the dust cover should be installed on the impeller and opened before the machine is filled with heat transfer oil.

3. The magnetic pump shall not be less than 30% of the continuous operation under the design flow. If it is necessary to operate under this premise, the bypass pipe should be installed at the outlet, and the flow will reach the minimum.

4. Check the looseness of the anchor bolts, whether the temperature of the stainless steel magnetic pump casing is consistent with the inlet temperature, the fluctuation of the outlet pressure gauge and the vibration of the pump.

5. Pay attention to no noise during the operation of the magnetic pump, and deal with it in time if it is found to be in normal condition.
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In the last issue, we talked about several reasons for the low efficiency of the mortar pump. Today, we will teach you how to carry out the daily maintenance of the mortar pump, so as to improve the operating efficiency ratio of the mortar pump:

1 strictly follow the operation procedures and requirements of each model of mortar pump.

2 whenever the operator changes shifts, he should check the lubrication of each component.

3. After the mortar pump is replaced with a new bearing, it should be cleaned and replaced with a new oil after 100 hours of operation. In the future, the oil should be changed every 1000-1500 hours of operation, and the grease should be changed every 2000-2400 hours of operation.

4 always check whether the operating temperature of all bearings is within the normal range. The temperature of the bearing shall not be higher than the ambient temperature by 35 ℃; The maximum temperature that the bearing can bear: the maximum temperature of rolling bearing shall not exceed 75 ℃, and the maximum temperature of sliding bearing shall not exceed 65 ℃.

5 always pay attention to the operation of the equipment. Once it is found that the mortar pump emits abnormal sound or vibration during operation, stop the machine in time and find out the cause and solve it.

6 always keep the pump and surrounding environment clean and tidy, and eliminate running, emitting, dripping and leakage in time. The sealing meets the requirements.

7 remind the maintenance personnel to take up their posts regularly, check the equipment and deal with the problems found in time.

8 if the ambient temperature of the mortar pump is low, when the pump is stopped, all waste liquid in the pump body should be drained in time to prevent the cracking of the casing and parts.
vacuum unit of pre pumping

What should be paid attention to when repairing multistage centrifugal pump

For the maintenance of multistage pump, if conditions permit, it is better to read the maintenance manual and general assembly drawing of the manufacturer first to see what special points need attention.

1、 During disassembly:

1. Before removing the thrust bearing, use a dial gauge to measure the clearance of the balance plate and make records;

2. When the multistage pump is disassembled, all parts must be marked according to the original assembly order to avoid confusion and wrong assembly during reassembly;

3. Small parts (such as keys) that are not convenient for marking can be placed together with the impeller or guide vane (middle section) of the same level.

4. During disassembly, you can intuitively feel whether there are abnormal parts, such as loose fitting.

2、 Parts maintenance:

1. Visually check whether the surface of each part is normal, and all mating surfaces must be free of collision, scratch, corrosion, etc;

2. Check whether the tolerance of key fitting parts is qualified by measuring tools;

3. Measure whether the clearance of impeller seal ring, shell seal ring, guide vane seal ring, interstage shaft sleeve, etc. is within the allowable range, and replace it if it is excessively worn;

4. Check whether the bearing is in good condition;

5. All sealing rings and gaskets shall be replaced with new ones;

3、 Reassembly:

1. Install the rotor and conduct dynamic balance test again;

2. Reassemble all parts in the reverse order of pump disassembly. During reassembly, pay attention to measuring the clearance value of each sealing ring again to ensure there is no error;

3. Before installing the balance disk, the total rotor runout shall be measured;

4. After installing the balance plate, measure the half string quantity of the rotor.

5. Compared with the total string quantity and half string quantity required on the general assembly drawing of the manufacturer, it shall basically meet the drawing requirements. Generally, the half string amount is about half of the total string amount.

6. Tighten all main bolts evenly, paying attention to the diagonal;

7. Suck a dial indicator on the shaft, rotate the shaft to mark the balance plate, and the tolerance shall not exceed 0.06 as per the drawing requirements;

8. When installing the thrust bearing, attention shall be paid to adjusting the clearance of the balance disc. The adjustment ring in front of the bearing shall be used to adjust the clearance of the balance disc to the requirements of the drawing.
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Working principle of pipeline pump

Pipeline pump can send water out because of 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 blades promote 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 of Shuiyuan is pressed into the inlet pipe through the pipe network. In this way, continuous pumping can be realized. It is worth mentioning here that the centrifugal pump can be started only after the pump shell is filled with water before starting, otherwise, the pump body will be heated, vibrated, the water output will be reduced, the pump will be damaged (referred to as "cavitation&quot and the equipment accident will be caused!

There are many types of pipeline pumps. The common classification methods are as follows

According to the impeller suction mode, it is divided into single suction pipeline pump and double suction pipeline pump.

According to the number of impellers: single-stage pipeline pump and multi-stage centrifugal pump.

According to the impeller structure, it is divided into open impeller pipeline pump, semi open impeller pipeline pump and closed impeller pipeline pump.

According to the working pressure, it is divided into low-pressure pipeline pump, medium pressure pipeline pump, high-pressure pipeline pump and vertical pipeline pump.

Five key points for use of pipeline pump:

Test run: check whether the connecting parts are loose; Turn the coupling manually to rotate the rotor for several turns, and check whether the unit rotates flexibly, whether there is sound and uneven weight, so as to judge whether there is foreign matter in the pump or whether the shaft is bent, whether the seal is installed correctly, etc; Check whether the clean No. 20 lubricating oil in the sealing cavity is filled with 1 / 2 of the cavity space; Whether the surface of the pump unit is clean; Unit steering no-load test.

Manual start: fill the pump (for the first time), slightly open the outlet valve and start the motor. When the pressure rises and it is confirmed that the pump unit operates stably, gradually open the outlet valve to the working condition.

Operation inspection: when the pump operates normally at power frequency (frequency conversion), the readings of ammeter, voltmeter, inlet and outlet vacuum gauge, pressure gauge and flowmeter of the pump unit shall be regularly checked and recorded. Whether the vibration, noise and temperature rise of the unit are normal. There shall be no obvious aviation oil leakage at the shaft seal.

Normal shutdown: close the discharge valve to make the pump light load and stop the motor.

Emergency stop condition:

The indication of pump motor working ammeter is abnormal (too large or too few); The pump system makes abnormal noise.

The vacuum pressure gauge at the inlet and outlet of the pump indicate abnormally, the pump body vibrates greatly and makes abnormal noise, and the performance is seriously degraded.

The pump motor produces odor, aviation oil leaks from the shaft seal, and the bearing temperature exceeds 75 degrees.
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Causes of wear of self-priming pump shaft

There are many reasons for the wear of the self-priming pump shaft, but most of them are due to the normal wear of the self-priming pump shaft because it has been used for too long. There are other reasons, of course. For example, it is caused by eccentric wear of the self-priming pump shaft, shaft bending, assembly error, too large centering deviation of the pump rotor and the motor rotor, etc.

Photo of self-priming pump shaft wear causes of self-priming pump bearing wear most of the eccentric wear of self-priming pump shaft is caused by shaft bending, and the wear caused by too loose bearing inner ring or bearing damage at the bearing journal also often occurs. Treatment methods: Hot calibration, cold calibration, mixed calibration, etc.

Most of the shaft bending occurs on multistage centrifugal pumps and submersible pumps because the shafts of these pumps are relatively long. The rotor dynamic imbalance is too large, the rotor vibrates, and the foundation level of the self-priming centrifugal pump is too poor. Another reason is the sagging caused by untimely turning, the temperature difference between the upper and lower parts of the rotor will cause deformation, and the vibration caused by centering deviation when the dynamic imbalance of the rotor is too large.

Self priming centrifugal pump is one of the machines that pump or pressurize liquid. The self-priming pump transfers the mechanical energy or other external energy of the prime mover to the liquid to ensure that the energy of the liquid will increase. It can be mainly used to pump the liquid, including oil, water, emulsion, acid-base liquid, suspended lotion, liquid metal, etc.

Shaft wear often occurs in the long-term operation of non sealed self-priming pump. After analysis, the wear of the self-priming pump shaft is caused by the following reasons.

(1) When assembling the bearing, it is caused by insufficient or no interference between the bearing inner ring and the main shaft.

(2) The alignment deviation between the pump rotor and the motor rotor is too large, and there will be too much vibration during the operation. If the bearing wear is serious, there will even be jamming, resulting in shaft wear.

(3) Compared with the mechanical seal, the traditional packing seal has poor wear resistance and short service life. If the water leakage of the shaft seal increases and the water blocking failure of the water retaining ring causes water inflow of the bearing chamber and bearing damage.

(4) High temperature sintering caused by rapid temperature rise will occur when the bearing is stuck due to lack of oil or oil seal failure suction and the impurities contained in the lubricating oil. When the self-priming pump shaft is worn, the traditional solution is repair welding or machining repair after brush plating. However, there are certain disadvantages in both. The stress generated by repair welding at high temperature cannot be completely eliminated, which is easy to cause material damage. Causing the component to bend or break.

Brush plating is limited by the thickness of the coating, and it is easy to peel off. Both methods need to use metal for repair, which will still cause re wear under the effect of various comprehensive properties. The wear of the self-priming pump shaft can be repaired by using special materials. High temperature will not be generated during repair, which can prevent the influence of repair welding thermal stress, and will not be limited by the unilateral wear of the shaft during repair. This special material can absorb the impact of external force and prevent the possibility of re abrasion.
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This situation is caused by various types of instability, such as the combined action of turbulence, backflow and vortex that may occur in the impeller when the pump operates under the condition of small flow. Sometimes referred to as "de flow" or "hydrodynamic" cavitation, these flow patterns will intensify at small flow rates. The flow rate at which this occurs will vary from impeller to impeller.

2. Outlet reflux

Outlet backflow is a similar situation, which may cause pitting damage at the blade tip and sometimes at the volute tongue of (volute pump). It may also be caused by the pump running at a small flow rate.

(3) entrained air

Entrained air contains a variety of situations in which vapor bubbles are already present in the liquid before reaching the pump. When they reach the impeller inlet, exactly the same thing happens, as if they were created at that point. In other words, after reaching the blade, the steam bubble begins to bear the increasing pressure and thus collapses, causing the same damage as cavitation at the same position.

Since the entrained air causes the same pitting damage to the impeller at the same position as the vaporization cavitation, it may cause confusion in fault diagnosis, especially in the same working condition, the two may occur at the same time. However, rapid comparison of npsha and NPSHr, combined with visual inspection of pipe characteristics, is often helpful to determine the root cause of so-called "cavitation" and solve the problem of entrained air.

4. Similarities and differences

Conventional vaporization cavitation, entrained air and reflux cavitation will all lead to pitting damage on the impeller, which is caused by the formation of bubbles and subsequent collapse. The difference between them lies in the method of forming bubbles and the location of the impeller damage caused thereby.

As the severity of all these conditions increases, so will noise, vibration, and impeller damage. Under severe conditions, pitting damage will spread to the entire impeller and may also extend to the pump housing.

Discrimination of cavitation

In general, the big problem is how to determine which of the above three hydraulic conditions is when encountering the common symptoms of noise and vibration.

The flow rate of the pump can be reduced by adjusting the opening of the outlet valve of the pump, and then it can be judged according to the effect of the flow rate change on the noise and vibration. Adjusting the outlet valve of the pump to reduce the flow through the pump will produce three possible situations:

1) The noise and vibration will be significantly reduced or even completely eliminated.

2) Noise and vibration may become more serious.

3) There is little or no change in noise and vibration.
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