Maintenance of magnetic pump

Precautions before starting and operation of magnetic pump:
A remove the dirt around the machine and equipment that endangers the safety of the machine and equipment and the actual operating staff.
B before driving, fill the pump with the liquid to be transported (if the pump is sucking), open the inlet valve, close the outlet stop valve, and connect the power supply.
C. connect the power supply and check whether the rotation direction of the pump is appropriate.
D. the generator set shall be put into trial operation for 3-6 minutes. If there is no abnormal condition, funds can be put into operation.
F when starting up for the first time after long-term shutdown or pump maintenance, remove the cooling fan cover of the motor and manually switch it off, check whether the magnetic pump rotates flexibly, and install the cooling fan cover after confirming that there is no problem.
2. Normal shutdown of magnetic pump
First turn off the stop valve at the outlet, and then turn off the power supply.
3. Emergency braking
Stop the motor immediately, and then close the outlet valve and inlet valve.
4. Overhaul and maintenance of magnetic pump
Regularly maintain the pump and motor, and replace vulnerable parts.
When it is unnecessary to shut down for a long time, clean the flow passage in the pump with high pressure and disconnect the power supply.
No idling.
5. Common problems in the operation of magnetic pump
A pay attention to the pressure difference between the front, back, left and right of the suction end filter device. When the pressure difference rises, it means that the filter device is blocked by dirt, and the pump operation should be stopped to facilitate the cleaning of the coarse filter.
B. whether the discharge volume and working pressure meet the standard value; C. whether there is abnormal sound and vibration. If there is abnormal sound or vibration, it generally indicates cavitation or excessive bearing damage.
E. whether the pump produces cavitation: open the outlet gate valve of the pump. When the total flow reaches a certain amount, suddenly there is sound and vibration. At this time, amplify the gate valve again. If the total flow still does not increase, it indicates cavitation. In case of cavitation, the actual operation of exhaust pipe shall be carried out. Note: the magnetic pump must not run under cavitation conditions. If it runs again under such conditions, it will cause initial damage to the bearing.
F whether the current of the motor exceeds the rated voltage.
G. whether the temperature at each position of the pump is abnormally overheated.
H the working pressure of nitrogen pressure stabilization system shall be maintained within the required range.

Common pneumatic ball valve failures

Function of centrifugal pump press out chamber

37. What is the function of centrifugal pump? How many forms of DP?
Answer: the function of screw pump press out chamber is to correctly guide the liquid with minimum loss
The next stage impeller may be led to the outlet pipe, and part of the kinetic energy is converted into pressure energy at the same time.
There are three common types of diaphragm pump press out chamber:
(1) Spiral volute is used to collect liquid gear pump. Kinetic energy becomes pressure energy
It is carried out in the diffuser.
(2) Radial guide vane, which is fixed outside the impeller outlet
The role of.
(3) Ring type press out chamber, used on segmented multi-stage pump*
38. What is the texture color given by centrifugal spring leaves 7
Answer: the impeller of centrifugal pump is generally made of metal, which enters according to the liquid flow
It can be divided into single suction PR force and double suction impeller, which are mainly composed of blade and wheel
The two-part 6-wheel is used to fix the blade and fix the calling wheel on the pump shaft-l.
39. What is the function of centrifugal spring coupling 7
Answer: the function of centrifugal pump coupling is to connect the pump shaft with the prime mover shaft
Play a role in transmitting the energy of the prime mover, buffering axial and radial vibrations, and
Automatically adjust the operation of the prime mover and the slave machine.
40. How many LP couplers are used?
Answer: there are three commonly used couplings:
(1) Rigid coupling, suitable for small, low-speed words with little vibration
On each;
(2) Elastic coupling is suitable for high-speed equipment with variable load,
(3) Gear couplings are mostly used on low-speed heavy equipment.

electric high vacuum butterfly valve of three factors should be considered in the selection

Daily maintenance of high temperature heat transfer oil pump

1. Shutdown: cut off the power supply. Empty the liquid in the heat transfer oil pump, clean it, and rotate the impeller 180 degrees regularly to prevent shaft deformation until the oil pump cools down.
2. The heat transfer oil pump uses fuel with appropriate grade. Generally, No.0 diesel oil is used in summer and No.10 light diesel oil is used in winter.
3. The fuel used by the heat transfer oil pump shall be clean and free of any impurities and moisture. 4. It is normal to have a small amount of leakage at the beginning of the operation of the heat transfer oil pump. After time, the leakage will be reduced or stopped after the sealing surface runs in. Because the heat transfer oil pump shaft is equipped with a stuffing box at the front end, the sealing performance is relatively good, and at the same time, a mechanical sealing device is set in the bearing seat, so a large amount of leakage is impossible to occur, and a small amount of leakage can be discharged and received through the leakage pipe orifice.
5. The heat transferred from the transmission medium to the pump cover and bearing of the heat transfer oil pump is dissipated by the surface of the pump cover and bearing seat, so that the temperature of the bearing seat can adapt to the temperature of the shaft sealing performance. Therefore, when selecting the installation position of the heat transfer oil pump, the heat of the pump cover and bearing seat should be easy to diffuse without any heat storage.
6. Two ball bearings are set in the bearing seat. A ball bearing on the pump impeller side of the heat transfer oil pump is lubricated with the transmitted heat transfer oil, and a ball bearing on the coupling side is lubricated with high-temperature grease: after 3000 hours of operation, each ball bearing is removed and cleaned with diesel oil, and the contact surface is checked for damage. If it is damaged, replace it with a new bearing. When installing the ball bearing near the impeller side, the side with dust cover should be installed towards the impeller, and heat transfer oil should be injected for lubrication before startup. The ball bearing near the coupling side is lubricated with compound calcium base high temperature grease. When the bearing is reinstalled, the side with dust cover should also be installed towards the impeller side, and the grease should be filled during installation. After the bearing runs for 48 hours, use a grease gun to inject supplementary grease into the pressure injection cup on the bearing cover.

vacuum pump manufacturers to repair cracks by measures taken

Chemical pump maintenance can be divided into several categories!

In the chemical industry, petrochemical industry, and many other industries, chemical pumps, centrifugal pumps, magnetic pumps and other equipment are repaired in order to restore their functions after deterioration or failure, including all kinds of planned maintenance and unscheduled fault maintenance and other maintenance. The basic contents of pump equipment maintenance include: equipment maintenance, equipment inspection, equipment repair and replacement.
Pump maintenance type
Post accident maintenance
In the maintenance strategy after the equipment works to the occurrence of obvious faults, the measures taken are to dismantle the damaged equipment or components for repair or renewal.
characteristic:
① The cost of maintenance is high and a waste of time, delaying normal production.
② Reserve various spare parts for replacement; Allocate more maintenance workers to deal with maintenance.
Regular preventive maintenance
Go to the site for maintenance according to the predetermined time interval, and repair or replace the equipment before major faults occur.
characteristic:
① The maintenance cost is less than that after the accident.
② Improper maintenance interval will cause unnecessary excessive maintenance.
Condition monitoring and maintenance
Based on the actual working condition of the equipment, it is implemented through the monitoring results of the equipment.
Whether to repair depends on abnormal phenomena such as mechanical vibration, bearing temperature and running noise.
If a selected parameter reaches the predetermined critical value, the equipment will be shut down for maintenance, so as to avoid more serious accidents.
characteristic:
① The maintenance goal is clear and the production efficiency is high.
② It is necessary to purchase corresponding testing equipment and train personnel.
Standard preventive maintenance procedures
Daily inspection work content
① Check whether the discharge pressure of the pump is normal.
② Check the sound, vibration and bearing temperature when the pump is running.
③ Check the pump body and auxiliary pipelines for leakage.
④ Check whether the coupling guard is loose.
⑤ Check the amount of lubricating oil and sealing cooling water.
⑥ Keep the equipment clean.
⑦ If any abnormality is found, report to the dispatcher.

2BE1-355 pump for bearing and mechanical seal of disassembling process

What is a shaft seal free centrifugal pump?

1、 Overview of shaft seal free centrifugal pump
Shaft seal free centrifugal pump is also known as packing free centrifugal pump. It is usually a vertical canned motor or a horizontal canned motor, which is driven by a wet winding motor without a shielding pad.
In this case, the pump and motor share a pressure pump housing, and there is a heat shield between the pump parts and the motor parts. The heat shield can be active or passive. The allowable medium temperature is as high as 420 ℃
2、 Characteristics of shaft seal free centrifugal pump
The bearing is lubricated by discharging medium. In practice, there is no limit to the system pressure, because the total leakage rate is slightly higher than the mark, so it can be used for dangerous media or valuable media.
3、 Special form of shaft seal free centrifugal pump
The special form of shaft seal free centrifugal pump is designed according to the application purpose.
·Special impellers for liquid and gas mixtures or suspended solids
·Sealing system specially used for nuclear reactor technology or sealing system with protective gas gasket
·Heating device specially used for quick condensing fluid, such as hot water circulating pump
·Protective cover with abrasion protection

vacuum unit of cooling cycle process

Large flow portable submersible pump

Maintenance method of large flow portable flood control and rescue submersible pump
Maintenance methods of portable submersible pumps, flood control submersible pumps, and large flow portable submersible pumps
Due to the high purchase cost of the large flow portable submersible pump, it is necessary to carry out regular maintenance before the damage of the large flow portable submersible pump is found in the process of use. Here are the maintenance methods of the large flow portable submersible pump for your reference:
Easily damaged parts: mechanical seal
Portable submersible pump oil chamber
The way to check in advance is to loosen the screw and check whether the oil level inside is full. If there is no oil inside, it is likely that an oil seal at the bottom is broken. If the oil seal is broken, it is recommended to return to the factory for maintenance and replacement. If there is still oil inside, please turn the pump upside down to let the oil inside out into a container and observe whether the oil contains water, If there is water in the oil, it means that the waterproof mechanical seal needs to be replaced.
The method to replace the waterproof mechanical seal is as follows: first remove the fixing screws at the water outlet of the submersible pump and remove the water outlet, then remove the impeller screws, find a rectangular wood, put one end on the bottom of the impeller, and use a hammer to knock down the upper end of the square wood with a hammer to lift the impeller down, and then remove the three bolts of the oil chamber cover plate and remove the cover plate to see the relevant parts of the mechanical seal, Before removing the mechanical seal, remember the installation sequence of the mechanical seal. It is recommended to take photos and archive them. After removing the old mechanical seal, install the new mechanical seal in the correct sequence, and then install the cover plate of the oil chamber according to the removal sequence, fill the oil chamber with transformer oil, and then install the impeller and water outlet.
Large flow portable submersible pump
To learn more about large flow portable submersible pump, recommended reading: Portable submersible pump
If you want to choose a self-priming pump and configure it on the power pump truck, it is recommended to read: large flow self-priming pump
If the delivered liquid contains a lot of impurities, it is recommended to choose stainless steel submersible pump for sewage

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Does the self-priming pump need to install a bottom valve?

The common self-priming pump refers to the external mixing suction and filtration self-priming pump. According to the rotation of the centrifugal impeller, the liquid flows into the volute, and then the pump shell generates a vacuum pump. In that way, the product of the self-priming pump will start, suck the liquid in from the inlet, and transport the liquid out according to the path of the impeller. It is the principle of the self-priming pump.
An obvious feature of self-priming pump different from centrifugal pump is that it does not need to inject water in the case of application. However, in the case of a single application, you must remember to inject water into the pump cavity. Because the pump shell itself does not store liquid, if you do not inject water in the case of a single application, the pump will rotate at a high speed, which will not only prevent the liquid from being sucked up, but also continue to burn the mechanical seal and other parts of the pump shell due to the high rotation speed. Therefore, you must pay attention to this.
So should the self-priming pump be installed with a bottom valve
01
If the bottom valve is not installed
What is the situation?
Generally speaking, there is no need to install the bottom valve. Generally, the inlet of the self-priming pump is equipped with a check valve, which is often referred to as this product, so after the pump is terminated, the liquid in the pump body cannot flow back to the original pool and be stored in the pump body, so there is no need to add liquid in the case of the second application,
02
If the bottom valve is installed
What about the situation?
If the bottom valve is refitted, the actual effect will be better, because sometimes if this product is destroyed, there is also a bottom valve as a guarantee, which is not easy to appear high speed, and after refitting the bottom valve, it will also reasonably ensure the reasonable suction lift of the pump!
Another special case, but if there is too much difference in the suction height width ratio, or the suction pipe is large, and the volume exceeds the liquid storage in the self-priming pump cavity, everything cannot work normally. At this time, it is necessary to refit the bottom valve to ensure the rapid safety of natural suction.

What is the liquid viscosity of acid resistant vacuum pump?

What are the common problems of diaphragm pump?

In essence, pneumatic diaphragm pump belongs to embolic pump, also known as control pump. There are four main combinations of it, which you can choose according to your personal needs.
Low flow
When you are faced with the problem of small flow of QBY pneumatic diaphragm pump, it is suggested that you consider these factors. First, check whether the inlet and outlet check valves of the diaphragm pump have been slightly worn. If the wear is serious, you must replace it in time. Otherwise, it will affect the normal operation of the diaphragm pump. Moreover, we need to check whether the inlet and outlet check valves are stuck by large particles. If it is stuck by large particles, the diaphragm pump will encounter certain difficulties in the process of suction, and discharge will also be abnormal to a certain extent. After finding the cause, we must solve it immediately to prevent affecting the work process and causing damage to interests.
There is no pressure at the outlet
Why is there no pressure at the outlet of the diaphragm pump? First, check whether the silencer of the diaphragm pump is blocked. If there is blockage, there is no way to discharge a large amount of gas in the diaphragm pump in a short time. In this way, the pumping speed is seriously affected, the speed is greatly slowed down, and there will be no pressure at the inlet and outlet. Second, it is recommended to check the upper and lower covers of the valve to determine whether the valve cover has air leakage or damage due to the impact of the valve core. Third, I hope you can pay attention to the inside of the pump. There is a central shaft inside the pump, and the central shaft has four sealing rings. If these four sealing rings are damaged, there will also be no pressure at the outlet of the diaphragm pump.
To sum up, this is the analysis of common problems of stainless steel diaphragm pump that Xiaobian will introduce to you today. In fact, to be honest, in addition to the above two problems, the diaphragm pump may sometimes not work.

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Why does the self-priming pump stop and then start without water?

Some users reported that in the process of using the self-priming pump, the water can be sucked up after the first filling, but the water can't be sucked up after the pump is stopped and then started. I don't know what the reason is. Let's analyze it below:
There are many kinds of self-priming pumps. The commonly used Self-priming pumps are ZX self-priming pump and ZW Self-priming sewage pump. There is a check valve disc at the inlet and the pump body is large, so this phenomenon is relatively rare. Some self-priming pump products, such as small stainless steel self-priming pump, have no check valve disc at the inlet, and the pump body is small. Some customers do not install the bottom valve at the bottom of the suction pool during the installation process. After stopping the pump, it is easy to backflow the water in the pump body back to the pool, so there is no water in the pump body when starting next time, Therefore, there is a phenomenon that water cannot be sucked after the pump is stopped. In this case, the problem can be solved by installing a bottom valve at the bottom of the water pipe, or installing a check valve at the inlet of the self-priming pump to prevent the water in the pump from flowing back.
Some users do not install a check valve in the vertical upward direction of the outlet pipe. After stopping the pump, the water in the outlet pipe will return to the pump body. If ZX and ZW Self-priming pumps are used, the water will also slowly return to the pool because the check valve disc at the inlet of the self-priming pump is not completely sealed. After stopping the pump for a long time, only part of the water in the pump body is left, and the water can be sucked up only when the pump is restarted.
Some of the outlet pipelines are very short. As a self-priming pump for temporary drainage, almost no valve is installed at the outlet. After the pump is stopped, because the water level in the pool is lower than that of the pump, the bottom valve is usually not installed in the installation of the self-priming pump, and no valve is installed at the outlet, so the air will be sucked into the pump body, and the water will flow back. If a valve is installed at the outlet, close the valve before stopping the pump, and the atmosphere cannot enter the pump body. The negative pressure formed before the self-priming pump will not be damaged, and it will be difficult for the water to flow back, and there will be no failure to suck water after stopping the pump.

How to judge the pumping condition and exhaust condition of vacuum pump?

How to deal with the failure of mortar pump?

Mortar pump is a kind of pump that can adapt to various working conditions, such as conveying acidic and alkaline clear liquid or pulp
Various corrosive pulp in smelting industry; Various dilute acids in sulfuric acid industry; All kinds of sewage produced by environmental protection industry. The pump is corrosion-resistant, wear-resistant and widely used. However, we must also understand the common faults of mortar pump in various applications, and the common faults and solutions of mortar pump
1) : reasons for rapid wear and tear of the pump: poor construction conditions (large particles), long escort interval, long water inlet pipe. Treatment methods: change the battlefield, increase the pressurization device, shorten the length of the water inlet pipe, and reduce cavitation.
2) : reasons for rapid wear of impeller Journal: low head of high-pressure pump, wrong packing position, divergence between pump shaft and rear cover. Treatment method: replace the high-pressure pump higher than the head of mud pump, replace the packing and adjust the degree of alignment.
3) : cause of pump vibration: the pump shaft and diesel engine (or motor) are in different centers, the impeller is unbalanced, and the bearing is damaged. Treatment method: adjust the concentricity, conduct balance test on the impeller, and replace the bearing.
4) : reasons for low outlet pressure and flow: there is air in the pump, the gap between the impeller and the front cylinder liner is large, the separator is closed loose, and the impeller or cylinder liner is worn. Treatment: discharge the gas in the pump, adjust the clearance, adjust the clearance of the separator friction plate, and replace the impeller or lining plate.
5) : the reason for the slow water filling of the pump: the gap between the front lining plate and the impeller is large, the outlet pipe cannot seal the air, and the air is completely emptied. Treatment method: adjust the gap, adjust the outlet pipe and vacuum device.
6) : the reason why the pump does not absorb water: the water is insufficient, the air in the pump cannot be discharged, the suction pipe leaks, and the gap between the front lining plate and the impeller is too large. Treatment method: water continuously, check whether the pipeline leaks, and adjust the gap between the impeller and the front lining plate.

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Maintenance method of pipeline centrifugal pump

ISG single-stage single suction pipeline centrifugal pump adopts the performance parameters of is centrifugal pump, which is cleverly combined and designed on the basis of general vertical pumps. At the same time, according to the needs of users, it can be made into a high-temperature pump, which is suitable for conveying hot water, high-temperature corrosive chemical pumps and oil pumps.
Measures to be maintained during the use of the pump:
1. The pipeline is full of liquid, and it is forbidden to pump for a long time under cavitation condition;
2. Regularly check the current value of the motor, which shall not exceed the rated current of the motor;
3. After long-term operation of the pump, when the noise and vibration of the unit increase due to mechanical wear, the pump should be stopped for inspection, and the vulnerable parts and bearings can be replaced when necessary. The overhaul period of the unit is generally one year.
4. Mechanical seal lubrication should be clean and free of solid particles;
5. It is strictly forbidden to work the mechanical seal under the condition of dry grinding.
6. Before starting, the pump should be turned for several rounds to prevent the graphite ring from being broken and damaged due to sudden starting;
7. The allowable difference of seal leakage is 3 drops / minute. Otherwise, it should be checked.

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Why can't the pipeline pump fill water?

There are many pump products, even if it is the same pump, the model will be different. Different kinds of pumps have different effects, so there are pumps in many fields. Of course, we also know that the pump with the best quality will encounter some thorny problems. For example, in the process of using the pipeline pump, some friends will find that it suddenly can't fill water. Why? Let's analyze it today.
There is air in the water inlet pipe and pump body
When encountering the problem that the pipeline pump can't supply water, don't panic first. We should recall whether we poured enough water into the pipeline pump before starting it? Some pumps do not need to be filled with water before starting, while some pumps must be filled with water before starting. Pipeline pumps belong to the latter category. If there is insufficient water in the pipeline pump, a small amount of air will remain at the inlet pipe. In this way, the pipeline pump will not be able to pump water. Even if you are filled with water sometimes, the water may overflow from the vent hole. I hope you can pay more attention.
Packing wear
You can check your stainless steel pipe pump to see if there is a problem of packing wear. The packing of some pipeline pumps is seriously worn due to long-term use. If the packing is worn to a large extent, it will affect the normal operation of the pipeline pump, which will not only make the pipeline pump unable to fill water, but also cause other problems. At this time, it is recommended to replace the packing. In addition, if the packing is not worn, you should check whether the packing is too loose. Too loose packing will also cause the pipeline pump to fail to fill with water.
The installation screw cap is not tight
Are the mounting screws of your pipeline pump tightened? If it is not tightened, then hurry to solve it. If the installation screw cap is not tightened, it will cause water leakage or electric leakage of the pipeline pump. At the same time, the pipeline pump may not be able to pump water.
Although the pipeline pump is only one kind of pump, it involves a wide range of fields. What I'm going to introduce here today is only one aspect of the pipeline pump.

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Treatment of eccentric reducer at the inlet of corrosion-resistant centrifugal pump

As for the installation of the eccentric reducer on the inlet pipe of the end suction centrifugal pump (i.e. the pump inlet is a horizontal inlet), in the teaching materials related to the pump piping standards, it is stipulated that the eccentric reducing pipe diameter orientation on the horizontal pipe (whether the horizontal part is upward or downward) is determined by the absence of liquid bags or air bags (in two cases):
1. When the medium enters the pump from top to bottom, the bottom flat eccentric reducer is used for installation, and there is no liquid bag;
2. When the medium enters the pump from bottom to top, the top flat eccentric reducer is used for installation, and there is no air bag;
Generally speaking, it is "from top to bottom, from bottom to top" To understand this reason, first understand a 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, and you only need to construct according to the drawings
1、 Cavitation phenomenon
Working principle of centrifugal pump: the driving machine drives the impeller to rotate through the pump shaft to generate centrifugal force. Under the action of centrifugal force, the liquid is thrown to the impeller outlet along the blade channel, and the liquid is collected through the volute and sent to the discharge pipe. The liquid gets energy from the impeller, which increases the pressure energy and speed energy, and relies on this energy to transport the liquid to the working place. When the liquid is thrown to the impeller outlet, a low pressure is formed at the center of the impeller inlet, and a pressure difference is generated between the liquid in the suction tank and the liquid in the impeller center. Under the action 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 flow flows into the impeller under the action of 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 vapor pressure pt of the liquid at the transmission temperature is mostly taken as the critical value of the liquid vaporization pressure), cavitation will occur.
2、 Methods to improve the cavitation resistance of centrifugal pumps include:
A. Improve the pump structure and reduce Δ HR, it is a pump design problem.
B. Improve the effective NPSH in the device: the main common method is to use the filling head suction device.
In addition, try to reduce the resistance loss of the suction pipeline and reduce the saturated vapor pressure of the liquid, that is, when designing the suction pipeline, try to choose measures such as larger pipe diameter, shorter length, fewer elbows and valves, and lower temperature of the transmitted liquid, which can improve the effective cavitation allowance of the device.
Well, after understanding the above knowledge points, let's take a look. What is the role of big and small heads? It is used to change the size of pipe diameter. So what is the use of changing the size of the pipe diameter at the inlet and outlet of the pump? It is mainly to reduce the flow velocity of the medium in the pipe, so as to reduce the friction when the medium flows in the pipe.

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How to use fluorine lined centrifugal pump correctly

 

After purchasing the fluorine lined centrifugal pump, the knowledge about how to use the centrifugal pump is relatively lacking, and it is easy to damage the centrifugal pump. So it is necessary to know and master the knowledge about how to use centrifugal pump correctly. When using a centrifugal pump, after the power is connected, carefully observe the operation of the centrifugal pump. The water outlet should be continuous and uniform, and the centrifugal pump can be used only when there is no vibration and noise. In case of sudden shutdown during operation, immediately disconnect the power supply and check the cause. The interval between two starts of a centrifugal pump shall be limited to the return of all the water in the pump. If it is started too early, the motor will be burned due to excessive resistance and water hammer in the water pipe. In addition, if the centrifugal pump is installed in the well, it should be noted that the flow of the centrifugal pump should meet the normal water output of the well, otherwise it will cause the empty machine to run and burn the motor.
Precautions for installation and use of fluorine lined centrifugal pump
1. Before the operation of the centrifugal pump, use a megger to check the insulation resistance of the motor stator winding to the ground, which shall not be less than 50 megohms at least;
2. When the voltage of the water pump exceeds ± 10% of the rated voltage, the water pump shall not be started.
3. To ensure the safety of use, the grounding wire in the four core cable must be reliably grounded to prevent electric shock accidents.
4. When the centrifugal pump is used, it should be lifted vertically, and it is not allowed to stand on the ground vertically, let alone fall into the sludge. When the pump is out of use, it should be cleaned and placed in a dry place, and pay attention to antifreeze;
5. Check the running direction of the rotor. It should rotate clockwise from top to bottom;
6. Outdoor switches or terminals shall be provided with rain proof and moisture-proof measures. It is forbidden to touch the switch when wet hands or bare feet to prevent electric shock;
7. When moving the centrifugal pump, the power supply must be cut off, and people are not allowed to contact the water source when the electric pump is running, so as to prevent personal accidents caused by electric leakage;
8. It is strictly forbidden to operate the motor in phase failure. If the fuse is found to be blown, it should be checked before continuing to use. It is not allowed to thicken the fuse arbitrarily;
9. When the centrifugal pump is running, it should be managed by a specially assigned person. If abnormal phenomena are found, it should be stopped immediately for inspection and troubleshooting;
10. After the centrifugal pump operates normally for half a year under the specified working medium conditions, the sealing condition of the oil chamber should be checked. If the oil in the oil chamber is milky or there is water precipitation, the mechanical oil and mechanical seal should be replaced in time. The water pump used under bad working conditions should be overhauled frequently;
11. The user should choose the appropriate flow head according to the actual working conditions to achieve the use effect. It is forbidden to use over flow, otherwise the motor will be overloaded if the flow is too large and the head is too low.

Piston vacuum pump refueling for instructions

How to deal with the blockage of sewage pump

How to deal with the blockage of sewage pump? Cold water should be used to cooperate with solvent for cleaning. If the blockage is relatively serious, the human resources will be connected after the pump body is disassembled and disassembled. Frequent disassembly of the pump will accelerate the damage of relevant components of the pump mouth ring. Therefore, it is necessary to avoid blockage as much as possible. In the process of operation, the following common problems can be used to reduce the blockage of the sewage pump.
After knowing how to deal with the blockage of the sewage pump, it is very necessary for the operators of machinery and equipment to apply appropriate maintenance methods to reduce the probability of blockage of machinery and equipment. As long as it is a sewage pump with qualified quality, there is very little blockage when solving the wastewater matching the specifications. The blockage is usually caused by the untimely daily maintenance. For example, if the pump is not cleaned immediately after the wastewater with high liposuction viscosity, the material will inevitably solidify over time, causing the centrifugal impeller of the pump to be stuck and blocked.
In order to better reduce this situation, customers must formulate timely maintenance and repair plans according to the application of sewage pumps and well-known brands, so as to lubricate the grease on time and ensure the actual effect of the lubrication of machinery and equipment. At the same time, the internal parts such as gear rack, centrifugal impeller, rolling bearing, piston rod, etc. should be inspected, the brittle or seriously damaged parts should be replaced immediately, and the hydraulic machine should be cleaned. In addition, before using the sewage pump and placing it for a long time, it must be operated in the sewage well for several minutes to achieve the actual effect of high-pressure cleaning of the pump chamber.
On the whole, the operators should be more concerned about how to deal with the problem of sewage pump blockage. It is generally proposed to assign full-time personnel to supervise and manage the sewage pump in the whole process, and regularly maintain the winding resistance of the submersible pump and the grounding resistance in the middle of the shell. Every 400 hours, the automobile oil in the grooves is removed and replaced up and down, especially the value traceability of the sealing ring between the centrifugal impeller and the pump housing. If it is a deep submersible sewage pump, it must be removed from the water in the future when it is not easy to reuse, so as to reduce the opportunity of motor rotor winding resistance and moisture return.
After the detailed introduction of the above content, I firmly believe that you also have a detailed understanding of how to deal with the blockage of the sewage pump. You only need to select the sewage pump with matching characteristics according to the specific working conditions and transported substances, and the blockage condition is very rare

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Why are sewage pumps more susceptible to corrosion?

Nowadays, the reason why the water pump is corroded is still an extremely serious problem faced by our country and even the world, involving all departments of the national economy, we must strengthen efforts to study and solve this problem.
At present, most sewage pump products are made of metal materials. The mechanism of metal corrosion is an electrochemical phenomenon. Experimental research shows that the corrosion of metals in sand water slurry is much more serious than that in clean water. The internal corrosion of the sewage pump is caused by the slurry. The solid particles in the slurry will accelerate the corrosion rate of the flow passage parts of the pump, and also aggravate the wear.
In clean water, iron oxidizes, releasing electrons and forming anodes
Fe= Fe2+ +2e ¯
At the same time, oxygen in clean water produces oxidation-reduction reaction and forms cathode
Oz +4e- +2H2o =40H¯
If the water contains hydrogen ions, which is an acidic solution, it will produce the reduction reaction of oxygen and form a cathode
2H+ +2e¯=H
The interaction between the products of anode and cathode produces corrosion products, which are iron hydroxide, ferric oxide or ferric oxide. In clean water, the products of the reaction form a protective layer that prevents the diffusion of oxygen to the cathode, thereby reducing the corrosion rate. However, in the solid water mixture, this protective layer will be damaged by the solid particles in the water, as well as the oxide and sulfide particles in the water, which is the main reason why the corrosion of sewage pump is more serious than that of centrifugal pump.

What effect does the blockage of the cooler of the vacuum unit have on the turbine?

Function of balance pipe of multistage centrifugal pump

The equalizing pipe of multi-stage centrifugal pump is a balancing method, not an equalizing structure. Whether it is an equalizing disc or an equalizing drum (or the combination of the two) is based on these methods to equalize the thrust. So what is the function of the equalizing pipe of multi-stage centrifugal pump?
From the outlet sealing ring of the multi-stage centrifugal pump, an external pipe is led to the inlet end of the multi-stage centrifugal pump, which is called the equalizing pipe. Its key function is to balance the axial thrust of the centrifugal water pump, reduce the axial shaking of the motor rotor, and prevent the friction between the impeller and the casing.
When the multi-stage centrifugal pump is running, high-pressure water is discharged from the impeller outlet, and one unit flows behind the impeller, so that the working pressure behind the impeller is basically the same as that at the outlet, while the outside of the coaxial cable of the blade is the suction end, and the working pressure is very low. In that way, there is a large pressure difference on both sides of the impeller, which will produce an axial thrust that is biased towards the pump inlet and parallel to the shaft, so that all motor rotors will press towards the suction side. In serious cases, it will cause friction or collision between the impeller and the pump body, endangering the safe operation of the pump, so it is necessary to balance it.
There are many methods to balance the axial thrust of multi-stage centrifugal pump, such as selecting double suction impeller or symmetrical sequencing impeller (multi-stage centrifugal pump), selecting equalizing hole, equalizing disc, equalizing drum, etc. The balance pipe is only a method to balance the axial thrust. It uses the balance pipe to lead the burden water behind the impeller to the inlet side, so that the working pressure on both sides of the impeller is in phase. This kind of method is simple in structure, but it cannot completely balance the axial thrust. The residual axial thrust must be borne by professionally installed thrust rolling bearings.

vacuum unit of vacuum pressure impregnation equipment of start and stop sequence

The application of fluoroplastic magnetic pump has great benefits

Fluoroplastic magnetic pump is different from self-priming or stainless steel magnetic pump. It is composed of pump, magnetic driver and motor. The magnetic drive of the key components is composed of an outer magnetic rotor, an inner magnetic rotor and a partition without magnetic permeability. Its application can well solve the problems of "running, emitting, dripping, leaking" and eliminate many potential safety hazards of seal leakage. Its flow passage parts are made of fluoroplastics and high-purity industrial ceramics, which have excellent corrosion resistance and sealing performance.
Advantages of using fluoroplastic magnetic pump:
1. No leakage: unlike the traditional centrifugal pump, the shaft seal structure is separated by a back cover with strong corrosion resistance between the driving magnet and the passive magnet, which can avoid leakage, pollution, corrosion and other problems.
2. Corrosion resistance: the pump head is made of European raw materials, which has strong corrosion resistance. Two pump body materials, cfrpp and PVDF, can be selected according to the delivered liquid. The material of pump shaft includes ceramics and SiC, among which ceramics can be used for general low corrosive liquids, and SiC can withstand high corrosive liquids.
3. Strong durability: use pump flow design software to calculate the optimal channel geometry, minimize fluid loss and improve the efficiency of blade exchange force.
4. Easy assembly: the internal parts of the pump are standardized, the assembly is simple, and the disassembly, inspection and maintenance are very simple, which is convenient and time-saving.
Precautions for use:
1. Prevent particle intrusion
(1) Do not design the magnetic moment smaller.
(2) It shall operate at the specified temperature. The medium temperature is strictly prohibited to be too high. Platinum resistance temperature sensor can be set on the outer surface of the magnetic pump diaphragm to detect the temperature rise in the annulus area, and alarm or stop when the temperature exceeds.
2. It cannot be used in systems with pressure
(1) Ferromagnetic impurities and particles shall not enter the magnetic drive and bearing friction pair.
(2) After transporting the medium that is easy to crystallize or precipitate, clean it in time (after stopping the pump, inject clean water into the pump room and drain it after running for 1min), so as to ensure the service life of the sliding bearing.
(3) When transporting the medium containing solid particles, it should be filtered at the inlet of the pump flow pipe.
3. Prevent dry friction
(1) Idling is strictly prohibited.
(2) Do not exhaust the medium.
(3) When the outlet valve is closed, the continuous operation time of the pump shall not exceed 2min to avoid overheating failure of the magnetic actuator.

How to reduce the oil return rate of vacuum unit?

Which pumps can resist sediment abrasion?

Cavitation erosion, sediment wear and their combined action are the important reasons for the damage of all kinds of pumps at present. Through experimental and numerical simulation research, it is found that the mechanism of cavitation erosion, wear and their combined action is the basis for developing the optimal design method of fluid machinery and improving the ability of fluid machinery to resist cavitation erosion, sediment wear and damage. Since the factors that affect cavitation erosion, sediment wear and their combined action behavior include not only flow field parameters such as velocity and pressure, but also sand particle and material properties, since the 1970s, the research in this field has been carried out and made progress in the aspects of cavitation erosion, wear and combined action mechanism, the interaction between various factors, as well as the anti-wear materials of pumps to improve wear resistance.
The protection of sediment abrasion of wear-resistant pumps is also based on the successful countermeasures selected after studying the causes. In turn, it provides theoretical support for the study of the mechanism of the rapid destruction of the flow surface of hydraulic machinery.
In terms of the classification of wear, the commonly used classification is adhesive wear, abrasive wear (abrasive wear), friction oxidation and fatigue wear. Wear resistant water pumps and turbines should be subject to abrasive wear if they work in sandy rivers. According to Lorentz's opinion, abrasive wear can be divided into three categories: consolidated abrasive, semi consolidated abrasive and free abrasive. Consolidated abrasive particles such as sandpaper, grinding wheel, file, etc. The abrasive particles are fixed on the surface of a material and cannot be moved. The result of wear is that the abrasive particles are ground, fallen off and damaged. Semi consolidated abrasive particles are not fixed, so the abrasive particles can slide and roll, but the degree of freedom is still small. For example, the bulldozer's shoveling and ploughing in piles of sediment belong to this kind of wear. Free abrasive particles, such as air flow or water flow, carry out contact or relative movement on the ground object, and furrows appear on the ground object. When the abrasive particles are fine, they can also grind the ground object smooth. At this time, the movement of abrasive particles has greater freedom. It can roll, slide, jump, etc. freely. The results of long-time wear are wavy and grooved. The sediment wear of wear-resistant pumps and turbines and the wear of wind and sand on fan blades during wind power generation belong to a type of free abrasive wear.
The surface damage of flow passage components seen by pumps and turbines working in clear water medium is called cavitation erosion. When bubbles in water burst in the high-pressure area, thousands of atmospheric pressures can be generated. When bubbles burst on the metal surface, they will have an impact on the metal, which is the basic consensus on cavitation erosion at present. In addition to cavitation erosion, there is also sediment abrasion on the surface of water pump and turbine flow passage parts working in sediment laden water flow. This kind of cavitation erosion and abrasion that exist at the same time is called sediment abrasion (combined action of abrasion and cavitation erosion). Wear and cavitation are caused by two distinct mechanisms, which are on the material surface of flow passage parts; There are also obvious differences in the characteristics of damage. In the test of muddy water tunnel, the submicroscopic observation of various parts of the specimen around the fluid can clearly show the differences between them and the changes of interaction and alternation.

prevent water ring vacuum pump unit from being corroded to methods

How to operate the canned motor pump correctly

Only when the shield pump is operated correctly and reasonably can the service life of the shield pump be prolonged! In the process of use, the use of pipeline shielded pump is particularly important!
First, exhaust (before and after separating the pump)
Before starting the pump: open the inlet valve (record the reading of the outlet pressure gauge) - open the outlet valve - open the reverse circulation pipeline valve (R type) - connect the cooling water (if any)
After starting the pump: open the inlet valve - start the pump - open the outlet valve - open the reverse circulation pipeline valve (R type)
Then, operate continuously and normally: after the air is discharged and the pressure gauge is stable, adjust the outlet valve until the pressure gauge indicates the allowable pressure range of the pump, and the operating current is normal (it should be about 80% of the rated current), and then operate continuously.
[the reading of the pump outlet pressure gauge = the pump inlet pressure + the pressure that the pump can increase
Then, stop the pump: close the outlet valve first, and then turn off the power.
Finally, the judgment of positive and negative pump:
Pump forward rotation:
Jog the power supply, and the pointer of TRG meter will return to zero after slightly swinging in the green area;
The outlet pressure gauge can reach the normal pressure;
The pump has no vibration and noise;
The running current of the pump is normal.
Pump reverse:
Jog the power supply, and the pointer of TRG meter swings to the red zone;
The outlet pressure gauge can not reach the normal pressure;
The pump has abnormal vibration and high noise;
The running current of the pump is lower than the normal value.

What are the advantages of dental vacuum unit?

Composition and working principle of magnetic pump

Magnetic pump is composed of pump, magnetic driver and motor. The key components of magnetic actuator are composed of external magnetic rotor, internal magnetic rotor and non-magnetic isolation sleeve. When the motor drives the outer magnetic rotor to rotate, the magnetic field can penetrate the air gap and non-magnetic substances, drive the inner magnetic rotor connected with the impeller to rotate synchronously, realize the non-contact transmission of power, and convert the dynamic seal into static seal. As the pump shaft and inner magnetic rotor are completely sealed by the pump body and isolation sleeve, the problem of "running, emitting, dripping and leaking" is completely solved, and the potential safety hazards of flammable, explosive, toxic and harmful media leaking through the pump seal in the oil refining and chemical industry are eliminated, effectively ensuring the physical and mental health of employees and safe production.
1、 Working principle of magnetic pump
N pairs of magnets (n is an even number) are arranged and assembled on the inner and outer magnetic rotors of the magnetic driver according to the law, so that the magnet parts form a complete coupled magnetic system with each other. When the inner and outer magnetic poles are opposite, that is, the displacement angle between the two magnetic poles Φ= 0, at this time, the magnetic energy of the magnetic system is the lowest; When the magnetic poles rotate to opposite poles, that is, the displacement angle between the two magnetic poles Φ= 2 π /n, at this time, the magnetic energy of the magnetic system is the largest. After removing the external force, because the magnetic poles of the magnetic system repel each other, the magnetic force will restore the magnet to the state of minimum magnetic energy. Then the magnet moves and drives the magnetic rotor to rotate.
2、 Structural features
1. Permanent magnet
The permanent magnet made of rare earth permanent magnet materials has a wide working temperature range (-45-400 ℃), high coercivity, good anisotropy in the direction of the magnetic field, and will not demagnetize when it is close to the same pole. It is a good magnetic field source.
2. Isolation sleeve
When the metal isolation sleeve is used, the isolation sleeve is in a sinusoidal alternating magnetic field, which induces eddy current on the section perpendicular to the direction of the magnetic line of force and converts it into heat. The expression of eddy current is:. Where PE eddy current; K - constant; N - rated speed of pump; T-magnetic transmission torque; F-pressure in the spacer; D-inner diameter of spacer; I. resistivity of the material; -- Tensile strength of the material. When the pump is designed, N and T are given under working conditions. To reduce eddy current, we can only consider from the aspects of F, D, and. Selecting non-metallic materials with high resistivity and high strength to make isolation sleeves has a very obvious effect in reducing eddy current.
3. Control of cooling and lubricating fluid flow
When the pump is running, a small amount of liquid must be used to wash and cool the annulus area between the inner magnetic rotor and the isolation sleeve and the friction pair of the sliding bearing. The flow of coolant is usually 2%-3% of the design flow of the pump. The annulus area between the inner magnetic rotor and the isolation sleeve generates high heat due to eddy current. When the cooling and lubricating fluid is insufficient or the flushing hole is blocked, the medium temperature will be higher than the working temperature of the permanent magnet, causing the internal magnetic rotor to gradually lose magnetism and the magnetic driver to fail. When the medium is water or water-based liquid, the temperature rise in the annulus area can be maintained at 3-5 ℃; When the medium is hydrocarbon or oil, the temperature rise in the annulus area can be maintained at 5-8 ℃.

Vacuum pump system used in degradable resin PBAT industry