How to isolate vibration for self priming pumps?

The installation of self priming pumps, especially newly installed pumps, must take vibration isolation measures and avoid laziness, otherwise significant vibration and noise may occur during use. When running a self priming pump, the noise is loud, which can damage the equipment and also cause noise pollution. Therefore, it is necessary to do a good job of vibration isolation. How can self priming pumps achieve effective vibration isolation?
1、 The vibration isolation components should be symmetrically arranged along the central axis of the self priming pump unit. The plane layout of rubber vibration isolation pads can be arranged in a clockwise or counterclockwise direction.
2、 When the vibration isolation components of the unit adopt six support points, four of them should be arranged at the four corners of the inert block or steel frame, and the other two should be set on the long side line and adjusted in position to ensure that the compression deformation of the vibration isolation components is as consistent as possible.
3、 When installing rubber isolation pads or damping spring isolators for vibration isolation of self priming pump units, generally, there is no need to bond or fix the rubber isolation pads and damping spring isolators to the ground, as well as to the inert block or steel frame.
4、 When rubber isolators are used for vibration isolation installation of unsealed self priming pump units, a steel frame should be installed under the base of the water pump unit and anchored installation should be adopted; The steel frame and rubber isolator should be fixed with bolts. Install anchor bolts in the ground or floor, and the rubber vibration isolator is fixed to the ground or floor through the anchor bolts.
5、 The edge line of the rubber isolation pad shall not exceed the edge line of the inert block; The supporting area of the steel frame should not be less than the supporting area of the top of the vibration isolation element.
6、 The rubber isolation pad is arranged in a single layer, and when the frequency ratio cannot meet the requirements, it can be arranged in multiple layers in series, but the number of isolation pad layers should not exceed five.
7、 When the rubber vibration isolation pad is set in multiple layers in series, each layer of vibration isolation pad is separated by a galvanized steel plate with a thickness of not less than 4mm. The steel plate should be flat, and the vibration isolation pad and steel plate should be bonded with adhesive. The flat size of the galvanized steel plate should be 10mm larger than each end of the rubber vibration isolation pad. The rubber vibration isolation pads bonded to the upper and lower layers of galvanized steel plates should be staggered.
8、 Before installing the ZXP stainless steel self priming pump during construction, it should be checked in a timely manner. During installation, the static compression deformation of the isolation element should not exceed the allowable value. Moreover, the vibration isolation components of the unit should avoid contact with substances such as acids, alkalis, and organic solvents.
Attention should be paid to these aspects in the design, manufacturing, and maintenance of self priming pumps. Only by following the requirements can vibration and noise be reduced, and equipment damage be reduced. If it cannot be resolved, you can consult us.

Why vacuum coating should be coated under vacuum conditions?

How can a self priming pump meet the standards?

Standard self priming pumps are being used in an increasing number of operating conditions, and only those that meet the following conditions are truly self priming pumps:
1. The self priming pump is a vertical self priming pump, with the motor and self priming pump coaxial.
2. All motors must have dedicated motors, and the entire rotor of the self priming pump should be supported by the bearings of the motor.
3. The original model of the automatic control self priming pump was WFB, but later on, other WFZB, WZB, and YWB were all modified based on the model of the old automatic control self priming pump.
4. The flow rate and head of the self priming pump should be within a range value. When the flow rate is high, the head of the self priming pump is small. When the head is high, the flow rate of the self priming pump is small.
5. The performance of the self priming pump can be adjusted using a valve, and the flow and head of the self priming pump can be controlled by the switch size of the valve.
6. When used at temperatures below 40 degrees Celsius, it does not affect the performance of the self priming pump.
7. The self-control self priming pump should have reliable rust prevention measures, the surface should be polished smooth, the welding should have no cracks, and collision should not scratch.
8. It is necessary to have an electromagnetic control valve, and no self priming pump is said to have no air control valve.

The Effect of Target Materials on Vacuum Coating

Prospects and directions for improvement of chemical pumps

 

The characteristics of chemical pumps should be: high quality, high reliability, and high environmental performance; While completing the task of transporting chemical media, it is also beneficial for the physical health of workers; Low expected service life cost; It can be organically integrated with the entire set of chemical equipment into a whole. However, in the chemical production process, various specific usage conditions and purposes have put forward various requirements for the manufacturing of chemical pumps.
The prominent feature of mechanical products used in the chemical industry is that the performance and requirements of mechanical products vary with the type and nature of the chemical medium being transported. Although the medium mentioned here sometimes also refers to water, oil, or other non hazardous substances; However, in most cases, chemical media refer to some very "terrifying" chemical raw materials; For example, some media with serious hazards (toxic, corrosive, and flammable media); Especially for media that are prone to chemical reactions, corrosive, and erosive, or solid or gaseous media containing the aforementioned components.
Changes in chemical composition and chemical element ratios in diverse chemical media can lead to changes in the properties of the chemical media; Causing an increase in the concentration of chemical media or having special flow properties (such as diffusive media, polymer solutions, etc.). Therefore, particularly strict quality requirements are often put forward for the purity of chemical media (GMP, polymers, electrolytes, etc.), which can be easily achieved through suitable chemical pumps. The diversity of chemical media has derived the diversity of requirements for chemical pumps. This makes it difficult for the chemical pump standard system to become a simple standard system. Compared to other fields, such as home appliances, home heating, water supply, drainage, etc., as well as chemical refining or automotive manufacturing, standardization has reached a considerable level not only in product production but also in product use. In chemical production enterprises, the standardization of chemical pumps has encountered obstacles in terms of technology and economy.
Let's talk about the direction of optimizing and improving chemical pumps below:
Firstly, standardization is very helpful and meaningful for the production and use of chemical pumps. But from the perspective of life cycle costs, what should economic standardization look like? Is it a detailed standardized long-term optimization calculation based on various specific usage situations? Or is it a rough standardized calculation? When will the hindrance of standardized investments that can only be recovered over a long period of time due to the adoption of new technologies and the development of new products end? How can we achieve a unified understanding of the standards for chemical pumps on both sides without harming the interests of either the chemical pump manufacturer or the chemical pump user? These questions can only be answered by strengthening dialogue between chemical pump users, industry associations, and chemical pump manufacturers. Possible solutions are: from the perspective of users, such as establishing long-term strategic partnerships with suppliers; Establish different levels of standardization within clearly defined levels (such as structural types, suppliers, series, materials, configuration methods, etc.) and integrated modular structures for chemical pumps. But what is important is still the issue of "service life cost".

How To Choose The Sealing Ring For Vacuum Pumps? What Materials Are Commonly Use

Daily maintenance of stainless steel multistage centrifugal pump

 

Stainless steel multi-stage centrifugal pump can be used for conveying different media, especially corrosive media. However, after long-term use, the centrifugal pump will inevitably have some failures. Therefore, it is necessary to carry out necessary maintenance during the use of the centrifugal pump. Now let's follow Zoomlion pump to understand the daily maintenance of stainless steel multi-stage centrifugal pump.
The daily maintenance of stainless steel multistage centrifugal pump is to check whether the running sound of the centrifugal pump is normal, whether there is vibration and leakage every day. If there is a problem with the centrifugal pump, it should be handled in time. In daily use, it is also necessary to keep the stainless steel multistage centrifugal pump clean, dry, free of oil and leakage.
For the daily maintenance of stainless steel multistage centrifugal pump, it is also necessary to check whether the coupling protection cover, foundation and other screws are fastened and loose. And whether the voltage of the centrifugal pump is within the specified range, whether the appearance motor wiring and grounding are normal, etc. if the wiring of the centrifugal pump is found to be faulty, it is necessary to immediately stop using and repair the centrifugal pump.
Maintain the stainless steel multistage centrifugal pump, and check whether the motor steering is correct. When the centrifugal pump operates normally, open the outlet pressure gauge and the inlet vacuum pump to gradually open the gate valve and check the motor load at the same time.
The above is the daily maintenance method of stainless steel multi-stage centrifugal pump summarized by Xiaobian for you. I believe you will have a certain understanding of the maintenance of stainless steel multi-stage centrifugal pump after reading it.

vacuum pump in tobacco industry of application

Common troubleshooting of laboratory centrifugal pumps

What faults can centrifugal pumps encounter in the laboratory, and how can these conditions be eliminated? Let's take a look. Diaphragm pumps
1. During use, the motor often fails to start, such as when the main power indicator light is on. At this time, the degree of carbon brush wear should be checked. If the carbon brush wear exceeds one-third of the total amount, it should be replaced with a new one in a timely manner. When the main power indicator light is not on, check if the indicator light fuse and indoor distribution board fuse are blown, and also check if the power cord is in good contact. If the fuse is broken, replace the fuse and keep the circuit smooth. The screw pump should also check the vacuum pump gauge and oil pressure indicator values. If the oil pressure is too high and the main engine cannot be started, it is necessary to check whether each oil circuit is blocked, especially whether the throttle hole is smooth. If it is not smooth, it should be cleaned to make it smooth.
2. If the bearing is damaged or its rotation is hindered, there is a lack of oil in the bearing or there is a lot of dirt in the bearing, which causes an increase in friction resistance. If the motor cannot reach the rated speed, the bearing should be cleaned or replaced in a timely manner. There is a layer of oxide on the surface of the commutator, even if it is burnt into unevenness or the brush does not match the outer edge of the commutator, which can cause a decrease in speed. The commutator and brush should be cleaned to ensure good contact. If there is a short circuit or open circuit in the rotor coil of a centrifugal pump, a multimeter can be used to check and rewind the coil. The rotor can cause rupture of the centrifuge tube, sample leakage, and rotor damage during use due to metal fatigue, overspeed, overstress, chemical corrosion, improper selection, imbalance of the rotating head during use, and temperature runaway. For the above situations, it is mainly required for the operator to master the operating procedures proficiently, select appropriate centrifugal pipes and rotors correctly, pay attention to strictly controlling each step of operation sequence, minimize unnecessary human damage, and use the rotor within the safety factor and warranty period. Magnetic pump
3. One of the reasons for the poor starting and cooling performance of the refrigerator is that the power supply is not available, and the power supply and fuse should be checked separately. If the voltage is too low and the safety device malfunctions, it can also prevent the refrigerator from starting. If the voltage is too low, it may be due to the low voltage of the power grid; Excessive wiring on the distribution board; The power cord is too long (ideal length is 3 meters), etc. Insufficient power cord capacity not only reduces voltage, but also causes accidents. Sewage pump
4. When the power supply voltage drops to 180-190VJ, the refrigerator cannot start, affecting the cooling effect. Poor ventilation performance, such as when the instrument is installed in direct sunlight or poorly ventilated areas, poor radiator effect, or the radiator cover is covered with dust, can also affect the cooling effect. The weight of the centrifuge tube is unbalanced and placed asymmetrically; There are foreign objects in the rotor hole, causing imbalanced load; Loose fixing nut at the upper end of the shaft, friction or bending of the shaft; The motor rotor will generate noise if it is not in the center of the magnetic field; Damage to the rotor itself can cause severe vibration and abnormal noise in the body. Self priming pump
Many times, it is caused by incorrect operation. After identifying the cause, correct operation can eliminate the abnormal phenomenon. During the work process, if any abnormal phenomena occur, the machine should be immediately shut down and forced operation is not allowed to avoid unnecessary losses or accidents. Chemical pumps.

Liquid Ring Compressor In Flash Steam Recovery On Offshore Platforms 

Which media needs to be transported with fluorine lined pumps

Fluorine lined pump is a special type of pump, its main function is to transport some special media. These media usually have certain corrosive or high-temperature and high-pressure characteristics, so it is necessary to use fluorine lined pumps for transportation. Fluorine lined pumps have been widely used in industries such as chemical, pharmaceutical, and electric power. Let's take a look at which media need to be transported with fluorine lined pumps.
Which media needs to be transported with fluorine lined pumps
Firstly, fluorine lined pumps are suitable for transporting corrosive media. In the chemical industry, many chemicals have certain corrosiveness, such as acids, alkalis, salts, etc. If these chemicals are transported using ordinary pumps, they can easily cause corrosion and damage to the pumps, and even cause serious damage to production equipment.
The fluorine lined pump has good corrosion resistance, which can effectively avoid the occurrence of these problems and ensure the safety and stability of production. Secondly, fluorine lined pumps are suitable for conveying high-temperature media. In some high-temperature production environments, ordinary pumps are difficult to withstand the impact of high temperatures, and are prone to problems such as pump body deformation and seal failure. The fluorine lined pump is made of special materials, which can withstand the influence of high temperature and ensure the stability and safety of the conveying medium. In addition, fluorine lined pumps are also suitable for conveying high viscosity media.
In some pharmaceutical, food and other industries, some media have high viscosity and it is difficult to transport them out using ordinary pumps. The fluorine lined pump adopts a special design and structure, which can effectively solve this problem and ensure smooth and stable transportation.
In short, fluorine lined pumps are a special type of pump suitable for conveying some special media. It has good corrosion resistance, high temperature resistance, and adaptability to high viscosity media, which can ensure the safety and stability of production. In industries such as chemical, pharmaceutical, and power, fluorine lined pumps have been widely used and have become indispensable and important equipment in the production process.

low-temperature environments in using vacuum pumps for precautions

Precautions for centrifugal pump testing

After the installation of various centrifugal pump products newly purchased and installed, it is necessary to conduct centrifugal pump testing work in advance. When conducting centrifugal pump testing work, the following methods and precautions for centrifugal pump testing should be followed
1. Before starting the centrifugal pump, it is prohibited to conduct idle and no-load testing. Liquid testing should be carried out according to the operating procedures specified in the centrifugal pump operating instructions. For the forced lubrication system, the temperature rise of the centrifugal pump bearing oil should not exceed 28 degrees, and the temperature of the bearing metal should be less than 93 ℃.
2. For centrifugal pumps with oil ring lubrication or splash lubrication systems, the temperature of the lubricating oil should not exceed 39 degrees, and the temperature of the bearing components should be less than 82 degrees.
3. When testing the centrifugal pump, the vibration value of the centrifugal pump bearing should also be checked. The vibration standard of the centrifugal pump bearing can refer to the relevant vibration standards of petrochemical rotating machinery.
4. During the testing process of the centrifugal pump, the operation of the centrifugal pump should be very balanced and noise free. The coolant and lubricating oil system should be normal, and there should be no leakage in the centrifugal pump and its auxiliary pipelines.
5. During the process of testing the centrifugal pump, attention should be paid to whether the current of the centrifugal pump motor is operating within the specified range. If the current exceeds the specified range, it indicates that the actual operating head is lower than the pump head. In this case, it is recommended to turn down the outlet valve to control the flow of the centrifugal pump and use it within the rated current range.
6. The leakage of various seals and media in centrifugal pumps shall not exceed the following standard requirements:
(1) Clean water centrifugal pump with mechanical seal: 10 drops/min for light oil and 5 drops/min for heavy oil
(2) Multi stage centrifugal pump products sealed with packing: 20 drops/min for light oil and 10 drops/min for heavy oil
(3) For magnetic drive pumps conveying toxic, harmful, flammable, and explosive media, no obvious visible leakage is allowed.

Liquid Ring Vacuum Pump in Chemical Production of Application

The generation of cavitation and impeller cutting in centrifugal pumps

 

Centrifugal pumps are prone to cavitation, which is related to many factors. What is the purpose of cutting the pump impeller and what role does it play?
1、 Cutting of Centrifugal Pump Impeller
1. Purpose of cutting:
A centrifugal pump has only one performance curve at a certain speed. To expand the working range of the pump, the method of cutting the outer diameter of the impeller is often used to change its working range from a line to a surface. When the cutting amount is small, it can be considered that the outlet angle and flow area of the blades before and after cutting remain basically unchanged, and the pump efficiency is approximately equal.
2. The expression for the cutting law:
Q '/Q=D2'/D2
H '/H=(D2'/D2) 2
N '/N=(D2'/D2) 3
In the formula, Q, H, N represent the rated flow rate, head, and shaft power of the pump
Corner marks' represent the corresponding parameters of the impeller after cutting
D2 represents the outer diameter of the impeller
2、 Cavitation and suction characteristics of centrifugal pumps
1. Cavitation phenomenon
According to the working principle of a centrifugal pump, the liquid flow enters 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. But if Pk decreases to a certain limit value (currently, the saturation steam pressure Pt of the liquid at the conveying temperature is often used as the critical value for liquid vaporization pressure), cavitation phenomenon will occur.
2. Serious consequences caused by cavitation:
(1) Generate vibration and noise.
(2) It has an impact on the working performance of the pump: when cavitation develops to a certain extent, a large number of bubbles are generated, which will block the flow channel, causing a significant decrease in the pump's flow rate, head, efficiency, etc.
(3) The material of the flow channel will be damaged, mainly due to fatigue erosion of the metal near the blade inlet.
3. Suction characteristics of centrifugal pumps:
1) The basic condition for pump cavitation is that the low liquid flow pressure Pk at the blade inlet is ≤ the saturated vapor pressure Pt of the liquid at that temperature.
2) Effective cavitation margin: The excess energy head that is higher than the vaporization pressure after the liquid flows from the suction tank and reaches the pump suction port through the suction pipeline. use Δ Ha represents.
3) The necessary cavitation margin of the pump: the total energy loss of the liquid flow from the pump inlet to the low pressure point K in the impeller, calculated using Δ Hr represents.
4)· Δ HR and Δ Differences and connections between ha:
Δ Ha> Δ No cavitation of the hr pump
Δ Ha= Δ Hr pump begins to cavitate
Δ Ha< Δ Severe cavitation of the hr pump
5. For a pump, in order to ensure its safe operation without cavitation, a safety margin should be added to the necessary cavitation margin of the pump, usually 0.5 meters of liquid column. Therefore, the allowable NPSH of the pump is:[ Δ Hr]= Δ Hr+0.5.
The expression for the allowable geometric installation height of the pump is: [Hg1]=(Pa Pt)/r-hA-S-[ Δ Hr].
Pa - suction tank pressure
Pt - Saturated vapor pressure of liquid at delivery temperature
R - Liquid gravity
HA-S - Flow loss in the suction pipe
[ Δ Hr] - allowable cavitation margin
7. The methods to improve the anti cavitation performance of centrifugal pumps include:
A. Improve the pump structure and reduce Δ HR is a design issue with the pump.
B. The main commonly used method to increase the effective NPSH inside the device is to use a filling head suction device
In addition, efforts should be made to minimize the resistance loss of the suction pipeline and reduce the saturated vapor pressure of the liquid. When designing the suction pipeline, measures such as selecting larger pipe diameters, shorter lengths, fewer elbows and valves, and minimizing the temperature of the liquid being transported can all improve the effective cavitation margin of the device.
8. Balance device for axial force
① Causes of axial force generation
a. The axial force A1 caused by the different distribution of fluid pressure on the front and rear sides of the impeller (low pressure on the wheel cover side and high pressure on the wheel disc) is directed from the back side of the impeller towards the inlet of the impeller.
b. The dynamic reaction force A2 generated by the different directions and velocities of fluid entering and exiting the impeller is opposite to A1, so the total axial force A=A1-A2, and the direction is generally the same as A1 (generally A2 is smaller).
② Balance of axial force
a. Adopting a double suction impeller: the impeller is symmetrical on both sides, and the fluid is sucked in from both ends. The axial force is automatically counteracted to achieve balance.
b. Opening balance holes or installing balance pipes: A: Open several balance holes on the impeller disc relative to the suction port. B: To avoid increasing hydraulic loss due to disturbance of the main flow after opening the balance hole, a balance pipe can be installed instead of the balance hole, which uses a small pipe to introduce pressure to the back side of the wheel disc.
c: Using balanced blades: Several radial ribs are cast on the back of the impeller disc, which drive the fluid in the clearance on the back of the impeller to accelerate rotation, increase centrifugal force, and significantly reduce the pressure on the back of the impeller.
d: Use thrust bearings to withstand axial force. Generally, small single suction pumps can withstand all axial force and prevent pump shaft movement by stopping the thrust bearing.
③ Balance of axial force in multi-stage centrifugal pumps:
a. Same method as single stage centrifugal pump
b. Symmetrically arranged impeller
c. Using a balance drum to partially balance axial force
d. Adopting an automatic balancing disc, all axial forces are automatically balanced.

Three Methods Of Vacuum Leak Detection

Precautions for inspection after assembly of fluorine lined centrifugal pump

When conducting maintenance and testing on fluorine lined centrifugal pumps after assembly, in addition to following normal maintenance procedures and standards, the following points should also be noted:
1. The concentricity of the pump rotor and volute. The degree of concentricity between the pump rotor and the volute is completely determined by the machining accuracy of the parts. It is required that the fluorine lined centrifugal pump rotor and the volute be concentric, in order to avoid friction between the dynamic and static components during operation;
2. Deviation between the centerline of the pump impeller flow passage and the centerline of the volute flow passage. The lower the deviation between the centerline of the impeller flow passage and the centerline of the pump casing flow passage, the higher the efficiency of the pump. The alignment deviation between the two flow channels should generally not exceed 0.5mm.
3. Is the tightening force of each bolt appropriate.
Fluorine lined centrifugal pump
4. Whether the internal clearances of the pump exceed the standard, and the data requirements of various pumps.
5. Whether the compression amount of the mechanical seal meets the requirements.
6. If necessary, conduct a hydraulic test on the casing of the high-pressure pump.

Bearing Damage Issues Of Analysis 

Can pipeline centrifugal pumps transport high-temperature hot water above 80 ℃?

 

Pipeline centrifugal pump is a type of centrifugal water pump suitable for industrial and urban water supply and drainage, pressurized water supply in high-rise buildings, garden sprinkler irrigation, fire pressurization, long-distance transportation, HVAC refrigeration circulation, bathroom and other cold and warm water circulation pressurization and equipment matching. The liquid that can be transported is also water below 80 ℃ or other liquids with physical and chemical properties similar to water.
Is it possible that pipeline centrifugal pumps cannot transport high-temperature liquids above 80 ℃?
No. Conventional pipeline centrifugal pumps cannot transport high-temperature liquids above 80 ℃. The improved IRG vertical hot water pipeline centrifugal pump and high-temperature pipeline centrifugal pump from Pump Manufacturing Co., Ltd. can achieve the transportation of high-temperature liquids. The IRG type hot water pipeline centrifugal pump produced by Pump Manufacturing Co., Ltd. can transport liquids with a temperature range of less than 120 degrees Celsius, while the high-temperature pipeline centrifugal pump can be used with a temperature range of less than 240 degrees Celsius.
If you are the procurement manager of an enterprise or public institution and want to purchase water pumps that deliver high-temperature hot water, you can contact our online customer service on the official website of Pump Manufacturing Co., Ltd. They will provide you with accurate pump selection and quotation services!

vacuum freeze drying

What are the working characteristics of a horizontal chemical pump for concentrated sulfuric acid?

 

At present, many enterprises have started to use concentrated sulfuric acid horizontal chemical pumps for the transportation of various materials. In actual use, this high-quality product has won high praise from many enterprise users. However, although many users often use this product, they still have no knowledge of its features. So let's take a look at the main working characteristics of an excellent concentrated sulfuric acid horizontal chemical pump?
1. Characteristics of good passability
The easy-to-use concentrated sulfuric acid horizontal chemical pump is very quiet during operation, and unlike other water pump products, it cannot achieve transmission through internal rotating components. Therefore, this product has good passability when conveying materials, and it can reach nearly one centimeter in diameter through the material. At the same time, it has minimal wear and tear during operation, and will not cause damage to the conveyed materials. It is particularly suitable for conveying viscous sludge and has a short service life.
2. Strong self absorption
Due to the strong suction force required by many users when using concentrated sulfuric acid horizontal chemical pumps, manufacturers have particularly strengthened the product's self suction ability when producing this product. This product has strong self priming ability, and even long-term dry suction will not damage the pump body. Once the pump body exceeds the load, it automatically stops working and has good self-protection function.
3. High security features
In recent years, the high-quality concentrated sulfuric acid horizontal chemical pump has been sincerely welcomed by many users because its pipeline is very spacious and suitable for conveying high viscosity products containing particulate matter. At the same time, the concentrated sulfuric acid horizontal chemical pump has high sealing performance, and will not pollute the environment when transporting volatile and Corrosive substance, and has high safety.
The advantages of this product can be seen from the working characteristics of the concentrated sulfuric acid horizontal chemical pump, which is also an important reason why many customers are willing to choose this product. The concentrated sulfuric acid horizontal chemical pump not only has good passability, but also improves the self suction ability of the product to meet customer needs. In addition, this product also has an important working feature, Shanghai Hongdong Pump Industry claims that it will not cause pollution and has high safety.

How To Solve The Problem Of Stopping The Roots Pump When Adding Lubricating Oil?

What factors can cause a decrease in the head of the sewage pump

(1) Motor reversal
Due to wiring reasons, the direction of rotation of the motor may be opposite to the actual requirement of the sewage pump. Therefore, when starting, it is generally necessary to observe the direction of rotation of the sewage pump. If the direction of rotation is reversed, any two wires on the motor terminal should be exchanged.
(2) Impeller channel blockage
If the flow channel of the impeller is partially blocked, it will affect the work of the impeller and cause a decrease in outlet pressure. Therefore, it is necessary to disassemble the pump for inspection and removal of foreign objects. To prevent the problem from recurring, a filtering device can be installed before the inlet of the sewage pump if necessary.
(3) Internal leakage occurs
When the gap between the rotating and stationary parts of the sewage pump exceeds the design range, it will cause internal leakage, which is reflected in a decrease in the discharge pressure of the pump, such as the clearance between the impeller mouth ring and the interstage gap of the multi-stage pump. At this point, corresponding disassembly and inspection should be carried out to repair or replace the components that cause excessive clearance.
(4) Cavitation occurs at the inlet
If the suction pressure of the sewage pump is too low, lower than the saturated vapor pressure of the pumped medium, cavitation will form. At this time, check whether the inlet Plumbing is blocked or whether the opening of the inlet valve is too small, or increase the liquid level of the suction pool.
(5) Speed decrease
The important factors affecting the head of sewage pump are the outer diameter of the impeller and the speed of the pump. When Ceteris paribus, the head of the pump is in direct proportion to the second power of the speed. It can be seen that the speed has a great impact on the head. Sometimes the speed of the pump decreases for some external reason, which will reduce the head of the pump accordingly. At this point, the pump speed should be checked. If the speed is indeed insufficient, the cause should be checked and a reasonable solution should be found.
(6) The operating point shifts towards high flow and low head
In general, centrifugal pumps have a continuous downward performance curve, and the flow rate gradually increases with the decrease of head. During the operation process, due to some reason, the back pressure of the pump decreases, and the working point of the pump passively shifts towards the low head and high flow point with the device curve, which will cause the head to decrease. In fact, this is caused by external factors such as changes in the device, and has no special relationship with the pump itself. At this point, simply increasing the pump back pressure, such as closing the outlet valve a little, can solve the problem.

FJ-300 Molecular Pump Unit

What precautions should be taken when using a self priming magnetic pump

What situations should everyone pay attention to when using self priming magnetic pumps in order to better use them? Many people are curious about this issue. Today, centrifugal pump manufacturers have brought some precautions for the correct use of magnetic pumps. Friends who are not familiar with it should come and take a look.
1. When using, everyone must pay attention that the outlet pipeline of the pump cannot use a check valve. If a check valve must be used, a vent hole should be set at the lower end of the valve.
2. When using a self priming magnetic pump for conveying, the flow rate, head, and self priming height must be within the specified range. If there is a significant difference from the regulations, it is likely to cause the pump to operate improperly due to suction.
3. It is strictly prohibited to transport solid particles or crystalline media.
4. When restarting after a prolonged shutdown, it is necessary to check whether the liquid in the pump body is sufficient before self priming.
5. After the self priming magnetic pump is installed according to the requirements, the power can be switched on, and inching mode is used to check whether the pump rotates normally and flexibly.
6. Self priming magnetic pumps are strictly prohibited from experiencing vacuum suction, so it is necessary to have someone specially monitor the liquid when it is about to be delivered to prevent it from being sucked out.
Did you have some gains after listening to the editor's introduction? If you haven't noticed these issues in your daily life, quickly correct them now, so that you can better use the magnetic pump product and avoid unnecessary malfunctions.

Typical Applications Of Vacuum Technology

Characteristics and classification of clean water pumps

 

Clear water pump is used for conveying 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 in high-rise buildings, garden sprinkler irrigation, fire pressurization, long-distance transportation, HVAC refrigeration cycle, farmland irrigation, bathroom and other cold and warm water circulation pressurization and equipment matching.
Characteristics of clean water pump:
Relatively good performance, with powerful motor device and reasonable body design, high efficiency and low noise. The location of the waterway is treated uniquely, which not only prevents corrosion and rust, but also has good wear resistance.
It has economic, practical, energy-saving design, and reasonable price.
Easy to set up and install, easy to use, with the use of new process design, promoting simple installation and convenient maintenance. It has a self priming function.
Common types of clean water pumps:
Self priming clean water pump: With good water resource quality and relatively fixed operating position, the suction head is within 3.5 meters, and the pipeline is stable. When used for daily water supply in wells and irrigation in plantations, it can reduce the inconvenience of water injection during pumping. The actual pump head is within 22 meters, and the working efficiency of chemical pumps is slightly weaker. When putting into operation for the first time, it is necessary to first inject circulating and emptying water before the water pump can start self priming.
Water injection type clean water pump: Water resources and water bodies have good mobility, and the pipeline is relatively not fixed. The actual pump lift within 2.5 meters is within 32 meters, and the pump flow can be adjusted according to demand. It is suitable for fruit planting professionals to spray pesticides and water supply, with high work efficiency. The suction pipe should ensure good sealing.
Submersible clean water pump: With abundant water resources, the pump has a low head and valves are more suitable for irrigation in fields and plantations that require a large amount of water. Due to the fact that the entire equipment of the submersible pump is placed in the water inlet and the axial water pushing increases, reducing the water flow rate will increase the pump load. Therefore, it is not necessary to install a valve in the drainage pipe of the submersible pump to avoid burning the motor due to excessive resistance when starting the pump due to valve shutdown.

Perflurane FFKM Rubber Seals

Can a deep analysis of the magnetic pump idle or not?

 

With the increasing environmental protection situation, more and more chemical enterprises are required to use magnetic pumps to transport various corrosive materials. As is well known, magnetic pumps cannot idle. As long as they idle for a few minutes, the friction between the shaft and the sleeve inside them will generate extremely high temperatures, quickly wear out graphite bearings and shafts, and even burn out the inner rotor.
In recent years, domestic magnetic pump manufacturers have claimed to be able to produce magnetic pumps that are resistant to idling. Is this true? Is the idle magnetic pump really useful? Can it really idle for a long time?
Today, I will introduce several details to you, hoping to be helpful to users.
At present, there are two main types of idle magnetic pumps produced by some domestic manufacturers. One is to use ceramic rolling bearings to replace the original sliding bearings. When there is a lack of liquid inside the magnetic pump, the friction coefficient of the rolling bearings is lower, and the heat generated is relatively less. Therefore, it can idle without burning the bearings and rotors. The disadvantages of this structure are that it cannot bear high torque, materials with slightly higher density cannot be transported normally, and ceramic bearing balls are fragile.
Another type is the LHC idling fluorine lined magnetic pump developed by Green Ring. This type of magnetic pump is a complete upgrade of the main shaft and shaft sleeve on the basis of the original tradition, and is filled with nano carbon powder technology to achieve the function of idling self lubrication. Relatively speaking, the latter is more technically and theoretically in line with the requirements of idling.

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The role of underwater pumps in low level transportation

 

When a centrifugal water pump is blocked by waste, it is necessary to pull the pump up in order to sort it, which is very inconvenient and therefore rarely used in practical activities. Therefore, using a submerged pump to carry out low-level transportation solves the problem of low-level transportation.
However, due to the use of a short shaft and the uneven axial force of the centrifugal impeller, all shafts are of a suspended wall structure, resulting in significant stiffness at the end of the centrifugal impeller during flipping. The longer the axis, the greater the stiffness. In order to solve this problem, the equipment on the shaft has bearings. However, because the whole shaft is a Flexible shaft, the bearing continues to suffer from unilateral damage, with a high wear rate, strong bearing shaking, and accelerated damage rate. Therefore, the underwater pump has a high frequency of damage. And the shaft is not suitable for making too long, usually within 2 meters. The bearings of the submerged pump are cooled and polished by water using the medium transported by the pump. If the medium of underwater concrete does not freeze and clean the bearings (such incidents can occur when the pump is empty and the inlet is blocked by dirt), it will cause burning of the tiles or even the motor.
The repair equipment of the submerged pump is very laborious. When transporting corrosive media, it is impossible to complete without lifting items. When a centrifugal water pump is transporting liquid, when the liquid level gauge is less than, it is required to fill the pump in order to produce water. Therefore, it is necessary to install a water pump bottom valve at the pump inlet. Over time, if the bottom valve of the water pump is corroded or stuck, exchange or repair is required, making the application inconvenient. Submersible pumps are generally used to transport cold water and rivers, but when used to transport corrosive liquids such as strong acids and alkalis, they are prone to motor erosion and power loss, making them very unsafe. After all, the submerged pump solves the problem of low level transportation, but it also incurs many difficulties in applications. The column type self priming pump is designed specifically for the transportation of low level liquids due to the aforementioned defects of the submerged pump. It can replace a long axis underwater pump on the road, with a naturally aspirated aspect ratio of up to 8 meters. It can be used as a bottom pump and a cabin cleaning pump in ships.

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Requirements for arrangement of centrifugal submersible pumps!

 

Centrifugal submersible pump is a type of submersible pump. With the development of the water pump industry and continuous technological innovation, centrifugal pumps are favored by many customers due to their high efficiency and safety advantages. However, there are still many customers who are limited by their professional knowledge and do not have a good understanding of it, resulting in various problems during the operation and even layout of centrifugal pumps.
1. The pump group should be arranged neatly, and the editor suggests aligning it with the outlet centerline of the water pump.
2. The electrical and process disciplines should be coordinated in a timely manner. When possible, the motor part of the water pump should be as far away from the explosion-proof zone as possible to save investment.
3. The water pump should be as close as possible to the liquid supply equipment to prevent small NPSHa.
4. The power side and pump side of the steam reciprocating pump should have positions for extracting pistons and pull rods.
5. When a vertical pump is not located below the pipe gallery or frame, space should be left above it for installation and maintenance of the pump body.

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What should I do if the metering pump malfunctions while adding medication?

When adding chemicals, precision requirements are quite important, so dosing pumps often use metering pumps, which can accurately control the amount of chemicals added. So when using a metering pump, what aspects and details should be carefully checked to avoid malfunctions?
Since not all metering pumps are equipped with a discharge valve, it is necessary to first check whether it exists, and then require it to be opened during the metering pump suction phase. If it is found that there may be gas leakage at the suction end of the metering pump, it is likely that the hydraulic end suction side connection may lack an O-ring or the suction valve connection may be loose, so it is also important to check here.
During use, it is important to avoid cleaning the hydraulic end of the metering pump with chemicals to prevent the ball and seat of the one-way valve from working properly. If there is indeed a malfunction in the metering pump, it must be promptly identified and resolved as soon as possible.
The first thing to do is to unscrew the screw fixing the pump head of the metering pump, and adjust the stroke length to 0% after the pump head is loose and before removing the pump head; At the same time, ensure that the electromagnetic shaft of the metering pump has sufficient pressure to maintain a stable connection, so that the diaphragm can be unscrewed.
Once the diaphragm is removed, check the safety diaphragm of the metering pump to ensure that it is intact and undamaged.
If there is any damage, it needs to be removed and replaced with a new one. Rotate the back plate and diaphragm clockwise until they are tightly attached; At the same time, it is necessary to adjust the back plate so that the leakage discharge hole is located at the bottom of the pump.
After the diaphragm in the metering pump is installed and the backplate leakage discharge hole is placed in a vertical position, install the pump head, ensuring that the suction valve is aligned with the leakage discharge hole, and the screws on the hydraulic end are aligned with the corresponding four holes. Then rotate to the position of 100% stroke length; Adjust the hydraulic end and diaphragm to the proper position during the operation of metering pump.

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Installation methods and operating procedures for pneumatic diaphragm pumps

If the installation details of pneumatic diaphragm pumps are ignored, long-term careful planning, research, and selection may still lead to poor pumping performance and affect the pump's service life. Pneumatic diaphragm pumps are a new type of conveying machinery that uses compressed air as the power source. For various corrosive liquids, liquids with particles, high viscosity, volatile, flammable, and highly toxic liquids, they can be pumped and absorbed completely. The diameter of the suction pipe of the pneumatic diaphragm pump should not be smaller than the diameter of the pump inlet end. For example, when transporting high viscosity fluids, the diameter of the suction pipe should be greater than the diameter of the pump inlet. The suction piping at the inlet end must be durable and free from wrinkles in order to generate a high vacuum state. The diameter of the outlet piping should be at least equal to the outlet diameter, or slightly larger to reduce friction losses. All piping and joints must be sealed without leakage, otherwise it will reduce the self priming capacity of the pump. Pneumatic diaphragm pump is a commonly used machinery in the chemical industry. After purchasing this pump, if it is not installed by specialized technical personnel, it is likely to delay production. In the following article, I will briefly introduce the installation steps and operating procedures of pneumatic diaphragm pump.
Installation method of pneumatic diaphragm pump
1. Location: Noise, safety, and other logical factors usually have requirements for the location where the equipment should be installed. Parallel installation with conflicting requirements may cause blockage in the usage area and affect the installation of other pumps.
2. Usage: Firstly, the position of the pneumatic diaphragm pump must be easy to use, which will facilitate daily inspection and debugging by maintenance personnel.
3. Air supply: Each pneumatic diaphragm pump should have a ventilation pipe that can provide enough air to achieve the ideal pumping flow rate. The air pressure depends on different pumping needs, but should not exceed 7BAR.
4. Installation height: Please fully consider the self suction capacity of the pneumatic diaphragm pump to avoid the problem of reduced self suction.
5. Pipeline: The pump position can only be determined after considering each possible location where pipeline problems may occur.
The installation of pneumatic diaphragm pumps should be selected at the connection of a short and straight inlet and outlet pipeline, and additional bends and pipe fittings should be avoided as much as possible. The pump body should be able to independently support all pipelines. Moreover, the pipelines should be arranged in an orderly manner to avoid stress on the pump body pipeline device. Flexible hoses can be installed to eliminate the stress caused by the natural reciprocating movement of the pump. If the pump body is to be connected to a fixed base, placing a buffer pad between the pump body and the base will help reduce pump body vibration.

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Disassembly of gear pump

The structure of a gear pump is simpler than that of a centrifugal pump, but the disassembly work is more laborious and mainly zero
The components are heavy and require high installation accuracy. They are also suspended on the beam and must be disassembled
Attention must be paid to safety. The disassembly of the components of the water pump can be divided into two parts, now using vertical axial flow
Take the pump as an example to illustrate its disassembly process
]Dismantling of the upper base
Firstly, remove the screws of the elastic coupling, loosen the screws connecting the motor to the base, and remove the motor. Support the rigid coupling of the pumping unit with wooden blocks to prevent the pump shaft from falling down, and then remove it
The connecting screws of the cap nut and bearing gland on the transmission uranium are used to seal the coupling and tighten the transmission
Lift the shaft up to a certain height, then remove the joint cap and thread of the rigid coupling, and remove the elastic
The coupling can be used to extract the transmission shaft from the upper base. Remove the elastic coupling again and roll it
Remove the bearing from the transmission shaft using a special tool. At this point, all the upper machine seats have been disassembled
2. Removal of the lower pump body
First remove the water inlet bell mouth, and then use a special tool to lift the impeller at the lower end of the pump
Open it to remove the entire impeller. For the water pump equipped with a movable blade field, remove the water inlet valve
After the bell mouth is opened, disassemble the rotating blade ring and then disassemble the impeller.

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Will stainless steel sewage pumps rust?

Customers usually believe that stainless steel centrifugal pumps will not rust, and rust is not a stainless steel pump. When brown rust spots (spots) appear on the surface of the stainless steel pump, the customer believes that there is a problem with the steel. In fact, this is a misconception about a lack of understanding of stainless steel. In some cases, stainless steel can also rust. There are many forms of damage to such surface facial mask. The following are common phenomena in daily life:
1. The surface of stainless steel contains dust or other metal particles attached to other metal elements. In humid air, the condensed water between the attached material and stainless steel connects the two to form a miniature battery, leading to a chemical reaction that generates electricity. The destruction of the protective film is called electrochemical corrosion.
As shown in Figure 2, in the presence of water and oxygen, the surface of stainless steel adheres to organic juices (such as melons, noodle soup, glutinous rice, etc.), forming organic acids that corrode the metal surface for a long time.
3. The surface of stainless steel adheres to acid, alkali, and salt substances (such as alkaline water and lime water splashed onto the wall), causing local corrosion.
4. In polluted air (such as atmospheres containing large amounts of sulfides, carbon oxides, and nitrogen oxides), liquid points of sulfuric acid, nitric acid, and acetic acid can form in the presence of condensed water, leading to chemical corrosion.
All of the above situations can cause corrosion and rusting of the protective film on the surface of stainless steel.
Therefore, to ensure that the metal surface is bright and does not rust, we recommend:
1. The surface of decorative stainless steel must be regularly cleaned and scrubbed to remove deposits and eliminate external factors that cause modification.
2. Coastal areas should use 316 stainless steel, which can resist seawater corrosion.
3. Some chemical components of stainless steel pipes on the market cannot meet the corresponding national standards and cannot meet the requirements of 304 materials. Therefore, it can also cause rusting, which requires users to carefully select products from reputable manufacturers.

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Differences in self priming centrifugal pumps

In order to better discharge the gas in the suction pipeline and generate a certain vacuum value during the operation of general centrifugal pumps, exhaust pipe measures must be adopted. For small pumps, the pump casing and water inlet must be filled with water before starting. In order to better avoid water jumping, a single side water pump bottom valve is installed at the bottom of the water inlet that opens when water flows up and closes when it flows down; Generally, centrifugal pumps with large water seepage specifications above 300mm are not equipped with bottom valves, but only use professional vacuum equipment to vacuum drinking water. There is no doubt that starting the water supply pump will cause inconvenience and lead to hasty consumption.
Principle: Centrifugal pumps operate by using the rotation of the impeller to generate centrifugal motion of water. Before starting the water pump, it is necessary to fill the pump casing and suction pipe with water. Then, start the electric motor to push the impeller and water to perform high-speed running fitness exercise. The water produces centrifugal motion and is thrown towards the edge of the impeller. It is then injected into the pressurized water pipeline of the water pump through the gate of the volute pump casing.
Structure: A centrifugal pump operates by using the rotation of the impeller to generate centrifugal motion of water. The main structure of a centrifugal pump is composed of six parts: impeller, pump casing, pump shaft, rolling bearing, sealing ring, and sleeve joint.
The structural type of self priming centrifugal pumps has been improved, overcoming the shortcomings of general pipeline centrifugal pumps. The advantage of a self priming centrifugal pump is that the pump casing is a double vortex shell structure. The detergent outlet is located on the edge of the water pump impeller, and there is a large capacity vapor liquid separation chamber above the outlet. Other structures are similar to single pole single suction centrifugal pumps, including sealing rings, machine seals, shafts, and rolling bearings. When starting the self priming pump for the first time during operation, it is necessary to introduce a diversion channel into the pump casing, and the amount of introduction should exceed the centerline of the pump within the pump casing. Afterwards, the fully automatic suction pipe can be started anytime and anywhere, without the need to introduce water into the diversion channel, making the application more convenient than pipeline centrifugal pumps.
Principle: The design principle of a self priming water pump is to fill the pump casing with water (or the pump casing itself has water) before starting the pump. After startup, the high-speed operation of the impeller causes the water in the impeller channel to flow towards the vortex shell. At this time, a vacuum pump is generated in the channel, causing the water seepage check valve to open. The gas in the suction pipe enters the pump and reaches the edge through the impeller channel.

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Can a self priming pump be used for low water levels

Self priming pump is a common type of water pump, whose main feature is that it can draw liquid on its own without the need for external water supply. Therefore, self priming pumps are widely used in many fields, such as industry, agriculture, construction, and so on. However, is a self priming pump suitable for use at low water levels?
This article will explore the working principle of self priming pumps, the definition of low water level, and the applicability of self priming pumps.
Firstly, we need to understand the working principle of self priming pumps. A self priming pump is a centrifugal pump that works by drawing liquid into the pump body through centrifugal force, and then compressing and discharging the liquid through the impeller inside the pump body. The suction and discharge pipelines of a self priming pump are connected, thus forming a closed space inside the pump body. When the pressure inside the pump body is lower than atmospheric pressure, the liquid will be sucked into the pump body. Therefore, the suction height of a self priming pump is limited, usually around 5 meters.
Next, we need to understand the definition of low water level. Low water level refers to the water level being lower than the suction height of the self priming pump, which means that when the water level is below 5 meters, the self priming pump cannot function properly. This is because the working principle of a self priming pump requires the formation of a closed space inside the pump body, and under low water levels, there is insufficient negative pressure inside the pump body to absorb liquid.
Finally, we need to understand the applicability of self priming pumps. Self priming pumps are suitable for sucking liquids such as clean water, sewage, oil, etc. However, for liquids containing solid particles or fibers, the effectiveness of self priming pumps may be affected.
In addition, the suction height of the self priming pump is limited, so it is necessary to choose the appropriate pump type and installation position according to the actual situation when using it. In summary, the self priming pump cannot operate normally under low water levels, so it is necessary to consider the actual situation when selecting the pump type and installation location. If pumps need to be used at low water levels, other types of pumps, such as submersible pumps, centrifugal pumps, etc., can be considered.

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Vacuum assisted self priming centrifugal pump

1、 Overview of Vacuum Assisted Self priming Centrifugal Pump Products
Vacuum assisted self priming centrifugal pumps are currently widely used in vacuum assisted self priming centrifugal pump trucks. Due to the slow self priming time and low self priming height when using conventional self priming centrifugal pumps on pump trucks, vacuum assisted systems have been added to self priming centrifugal pump trucks in the pump industry. Vacuum self priming centrifugal pumps have been updated and replaced with several generations of vacuum assisted self priming centrifugal pump products, The new model belongs to a vacuum assisted self priming centrifugal pump product that can self suck up to 8 meters without vacuum assistance. On the basis of the vacuum assisted self priming centrifugal pump product, a vacuum assisted self priming centrifugal pump product with a vacuum assistance system has been added. In the case of a malfunction in the vacuum assisted system, this series can also self suck up to a height of 8 meters and 8 meters in 5 minutes. In the past, when the vacuum assisted self priming centrifugal pump had a malfunction in the vacuum assisted system, the self priming height of the self priming centrifugal pump was only about 4-5 meters Moreover, the self priming time is relatively slow and cannot achieve the effect of emergency rescue when used in flood prevention and rescue operations. Therefore, the newly developed vacuum assisted self priming centrifugal pump will be a more suitable product for the use of vacuum assisted self priming centrifugal pump trucks.
2、 Main characteristics of vacuum assisted self priming centrifugal pump
1. The 2019 vacuum assisted self priming centrifugal pump can achieve a self priming height of up to 8 meters without a vacuum pump.
2. The newly developed open impeller of vacuum assisted centrifugal pump has good anti clogging effect, and the diameter of solid particles is much larger than that of previous self priming centrifugal pumps. The 150 caliber can pass through 75mm.
3. The vacuum assisted self priming centrifugal pump can reach a self priming height of 9 meters without cavitation, and the self priming horizontal distance can reach 150 meters.
4. The impellers of vacuum assisted self priming centrifugal pumps are all made of stainless steel material, ensuring a longer service life. The pump body is made of ductile iron material, and the pump shaft is made of 3Cr13 material.
5. The vacuum assisted self priming centrifugal pump motor can use a permanent magnet energy-saving motor, and the flow head can be adjusted according to user needs to make the motor speed more energy-saving and meet the requirements of China's energy-saving product certification.
6. The diesel engine matched with the vacuum assisted self priming centrifugal pump truck can be selected from domestic or imported brands according to user needs, and the diesel engine speed can be 1500, 1800, and 3000r/min for different requirements.
7. The bottom of the vacuum assisted centrifugal pump body is equipped with an independent drain valve for draining water after use. And there is an independent maintenance port with a diameter of 150mm. During maintenance, the pump body and motor can be repaired without disassembling, which is convenient and fast.

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Misunderstandings in the operation and use of pipeline centrifugal pumps

 

1. Pipeline centrifugal pumps are matched with some pipeline centrifugal pumps. Users believe that this can increase the actual head, but in fact, the actual head of the water pump is equal to the total head to the loss head. After the water pump model is determined, the total head is fixed; The loss of head mainly comes from pipeline resistance. The smaller the pipe diameter, the greater the resistance, and therefore the greater the loss of head. Therefore, reducing the pipe diameter not only does not increase the actual head of the water pump, but also reduces it, leading to a decrease in pump efficiency. Similarly, when a small diameter water pump uses a large water pipe for pumping, the actual head of the pump will not be reduced. Instead, the loss head will be reduced due to the decrease in pipeline resistance, resulting in an increase in actual head.
2. High head water pumps are used for low head pumping. Some pipeline centrifugal pumps users believe that the lower the pumping head, the smaller the motor load. Under the misleading misconception, when choosing a water pump, the head of the pump is often chosen too high. In fact, for centrifugal pumps, when the pump model is determined, the power consumption is directly proportional to the actual flow rate of the pump. The flow rate of the water pump will decrease with the increase of the head, so the higher the head, the smaller the flow rate, and the smaller the power consumption. On the contrary, the lower the head, the greater the flow, and the greater the power consumed.
3. If there are too many elbows on the inlet pipeline of the centrifugal pump in the pipeline, it will increase local water flow resistance. And the elbow should turn in the vertical direction, and it is not allowed to turn in the horizontal direction to avoid gathering air.
4. When installing the water inlet pipeline, the horizontal section should be horizontal or upward. This will cause air to accumulate in the water inlet pipeline, reduce the vacuum degree of the water pipe and water pump, and reduce the suction head and water output of the water pump. The correct approach is to tilt the horizontal section slightly towards the direction of the water source, not horizontally, and not upward.
5. The inlet of the pipeline centrifugal pump is directly connected to the elbow, which will cause uneven distribution of water flow when passing through the elbow and entering the impeller. When the diameter of the inlet pipe is greater than that of the water pump inlet, an eccentric reducing pipe should be installed. The flat part of the eccentric reducer should be installed above, and the inclined part should be installed below. Otherwise, air will accumulate, water output will decrease or water cannot be pumped, and there will be a sound of impact. If the diameter of the inlet pipe is equal to that of the water pump inlet, a straight pipe should be added between the water pump inlet and the elbow, and the length of the straight pipe should not be less than 2-3 times the diameter of the water pipe.
6. If the outlet of the pipeline centrifugal pump is above the normal water level of the outlet pool, although the pump head is increased, the flow rate is reduced. If the water outlet must be higher than the water level of the water tank due to terrain conditions, elbows and short pipes should be installed at the pipe mouth to make the water pipe a siphon type and reduce the height of the water outlet.
7. When installing the bottom valve, the lower section of the inlet pipe is not vertical. If installed in this way, the valve cannot close on its own, causing water leakage. The correct installation method is to install the inlet pipe with a bottom valve, and ensure that the next section is vertical. If vertical installation is not possible due to terrain conditions, the angle between the water pipe axis and the horizontal plane should be above 60 °.

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Teach you how to correctly select a diaphragm pump diaphragm

Shanghai Pump Manufacturing Co., Ltd. teaches you how to correctly select a diaphragm to achieve twice the result with half the effort. The main component of a diaphragm pump is the diaphragm, so users must indicate the nature of the conveying medium when ordering, so that different diaphragms can be equipped at the factory. Generally, there are several types of diaphragms:
1. Ding Qing diaphragm is mainly used in oil resistant applications.
2. Neoprene rubber 5031 # is specially made by our company and is mainly used for resistance to acetone and various acids and alkalis.
3. Fluorine rubber 6021 # is specially made by our company and is mainly used for high temperature 150 ℃, toluene resistance, and corrosion resistance. But the price is higher than other diaphragms.
4. Food rubber, specifically used for the transportation of food and beverages.

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Common faults and treatment of mixed flow pump

 

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

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Analysis of low efficiency of multistage centrifugal pumps

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

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

 

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

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Common problems of vertical submerged sewage pump

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

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

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

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Five advantages of pipeline pump

 

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

Sugar factory compressor

Method of exhaust and water filling of centrifugal pump

 

The centrifugal pump will carry out the actual operation of exhaust and water filling when starting and running, and that can make the machine and equipment run better. So I will explain the water filling and exhaust methods of the machine and equipment to you next. Let's have a look.
Because the centrifugal pump generates vacuum pump after the pressure in the pump is pumped out by the centrifugal impeller, so in addition to the centrifugal pump and the self-priming pump with the centrifugal impeller immersed in water, water must be filled into the pump before each pump start, which is also known as the diversion channel. There are two ways to fill water: one is to fill water into the pump immediately (at this time, the air outlet should be opened to drain the gas in the pump); The second is to extract the steam from the pump, create a certain vacuum value (at this time, close the water outlet stop valve), and introduce water resources.
1. Install gate valves at the inlet and outlet to fill water. In this way, a gate valve is installed at the water inlet, and water can be filled into the pump after connecting the water pipe.
2. Fill with water by hand pump. Some water pumps are equipped with built-in hand pumps, and small and medium-sized hand pumps can also be purchased or made by ourselves. The stop valve must be installed on the inlet pipe. After the gate valve is closed tightly, fill the water press with a small amount of water to develop the diversion channel. After the water output of the hand pump, it indicates that the water pump has been filled with water and can be started.
3. Use vacuum technology to exhaust and fill water. The self-exhaust of centrifugal pump is the same as the negative pressure exhaust of mechanical pump, so the water-ring mechanical pump exhaust is used to fill the water channel.
Therefore, when the centrifugal pump cannot carry out the actual operation of exhaust and water filling normally, it must be repaired immediately to prevent endangering all normal applications of the machinery and equipment, or it will continue to cause a certain level of damage to the machinery and equipment.

How to select a vacuum pump?

The centrifugal pump manufacturer tells you the difference between centrifugal pump and self-priming centrifugal pump

The centrifugal pump manufacturer pointed out that in order to better discharge the gas in the moisture absorption pipe and generate a certain vacuum value when the centrifugal pump is working, the exhaust pipe must be used. For small pumps, the pump casing and water inlet must be filled with water before operation. In order to better avoid the jump of water injection, the bottom end of the water inlet is equipped with a unilateral pump bottom valve that opens when the water flows upward and closes when it flows downward; Generally, large centrifugal pumps with water seepage specifications above 300 mm are not equipped with bottom valve of water pump, but only use professional vacuum equipment to vacuum drinking water. There is no doubt that the operation of the feed pump will cause inconvenience, resulting in waste.
Principle: Centrifugal pump works by using impeller rotation and then water to produce centrifugal movement. Before running the pump, make sure that the pump casing and the moisture absorption pipe are filled with water. Then run the motor to make the pump shaft push the impeller and water for high-speed running fitness exercise. The water will produce centrifugal movement and be thrown to the edge of the impeller. The water will be injected into the compressed water pipeline of the pump through the flow passage of the volute pump casing.
Structure: Centrifugal pump works by using impeller rotation and centrifugal movement of water. The manufacturer of centrifugal pump pointed out that the basic structure of centrifugal pump is composed of six parts, namely, impeller, pump housing, pump shaft, rolling bearing, sealing ring and ferrule joint.
Centrifugal pump manufacturer
The centrifugal pump manufacturer said that the structural type of the self-priming centrifugal pump has been improved, and it has got rid of the insufficiency of the general pipeline centrifugal pump. The characteristic of self-priming centrifugal pump is that the pump shell is double volute structure. The detergent port is located on the edge of the pump impeller, and there is a large capacity vapor liquid separation chamber on the liquid outlet. Other structures are similar to single pole single suction centrifugal pumps, including sealing rings, mechanical seals, shafts and rolling bearings. When the self-priming pump is in operation for the first time, the water diversion channel must be introduced into the pump casing, and the introduction amount can exceed the pump centerline in the pump casing. After that, the fully automatic suction pipe can be operated at any time and anywhere without introducing the diversion canal, so the application is more convenient than the pipeline centrifugal pump.
Principle: The principle of self-priming pump is to fill the pump casing with water (or there is water in the pump casing itself) before the pump runs. After running, the impeller runs at a high speed to make the water in the impeller channel flow to the volute. At this time, the channel generates a vacuum pump to open the seepage check valve. The gas in the suction pipe enters the pump and reaches the edge through the impeller channel.
Structure: Self priming centrifugal pump is a kind of centrifugal pump, but it is different from centrifugal pump in that it has "self priming" characteristics. The basic structure of the self-priming pump is composed of a suction chamber, a liquid storage chamber, a scroll chamber, a liquid collecting hole, a vapor liquid separation chamber, etc.

What is the purpose of the vacuum pump used in the high gloss machine for mobile phone panel?

Advantages and disadvantages of magnetic pump

 

Advantages of magnetic pump:
1. Since the drive shaft of the magnetic pump does not need to penetrate the pump casing, but uses the magnetic field to drive the inner magnetic rotor through the magnetic field and the thin-walled transmission torque of the isolation sleeve, thus fundamentally eliminating the leakage channel of the shaft seal and achieving complete sealing.
2. The magnetic pump has overload protection when transmitting power.
3. The magnetic material and magnetic circuit design of the magnetic pump have high requirements, while the other parts have low technical requirements.
4. The maintenance and overhaul workload of magnetic pump is small.
Disadvantages of magnetic pump:
1. The efficiency of the magnetic pump is lower than that of the ordinary centrifugal pump, and it cannot operate at 30% of the lower rated flow, and it is more forbidden to idle.
2. Due to the poor wear resistance of the isolation sleeve material of the magnetic pump, the magnetic pump is generally used to transport the medium without solid particles and the magnetic particle material is forbidden to enter the pump.
3. The magnetic pump with general structure is allowed to transport the liquid containing solid particles with diameter less than 0.15mm (100 mesh) and mass fraction less than 5% (auxiliary system shall be added when exceeding).
4. The pump and motor are connected by a coupling. The coupling requires a high accuracy for the installation of the center line. Improper alignment will lead to the damage of the bearing at the inlet and the wear of the isolation sleeve against unilateral side leakage.
5. The magnetic drive of the magnetic pump has two modes: synchronous drive and asynchronous drive. The inner and outer magnetic rotors of the synchronous drive are equipped with permanent magnets, so the temperature of the liquid transported must be lower than the allowable temperature of the permanent magnet. A certain margin must be reserved. Although cobalt and samarium permanent magnets can reach 350 degrees Celsius, the actual use temperature generally does not exceed 260 degrees Celsius. High temperature on the other side may cause permanent magnet loss of magnetism. The magnetic pump with special structure can reach 450 degrees Celsius.
6. The magnetic pump has high requirements for the material and manufacturing process of the isolation sleeve. If the material is not selected properly or the manufacturing quality is poor, the isolation sleeve cannot withstand the wear of the inner and outer magnetic rotors, resulting in wear. Once it breaks, the medium conveyed will overflow, causing equipment failure and affecting the normal operation of the device.
7. When the temperature of the medium conveyed by the magnetic pump exceeds the specified value, it is necessary to provide cooling outside. For example, the heat insulation chamber is set, the pump chamber is filled with coolant with a pressure higher than the sealing pressure, and the inner magnetic rotor and bearing are cooled. The isolation sleeve with a interlayer can also be used. The interlayer is filled with coolant, or the pump body is equipped with a cooling jacket and a cooling coil. The single structure is complex and the cost is high.

Let your vacuum equipment work healthily and happily

What is molten salt submerged pump

RY-type molten salt pump is a single-stage, single-suction cantilever submerged pump, which is suitable for conveying molten salt (KNO3 53%, Na2NO240%, NaNO37%) with high temperature (temperature ≤ 600 ℃), for industrial departments such as ionic membrane caustic soda, alumina, etc., and also for conveying liquid with other high-temperature special media. RY-type molten salt pump is a series of molten salt pump products independently developed on the basis of years of production of high-temperature submerged pump and molten salt submerged pump, referring to the structure of similar foreign products. It is a special high-temperature pump for molten salt circulation system or molten salt transportation.
The structure of molten salt pump mainly consists of power system, transmission system and conveying system. The power system mainly includes motor and motor support. It is the power source of molten salt pump. The transmission system includes the main shaft and bearing bracket, which is responsible for completing the power transmission. The high-speed operation of the motor is converted into the operation of the impeller to generate the power to transport high-temperature molten salt. The conveying system is mainly composed of conveying pipes, which is used to complete the transportation of high-temperature molten salt.
Before determining the type selection of molten salt pump, the composition of molten salt used should be analyzed first. Including the type of molten salt, service temperature, melting point, gasification point, etc. On the whole, the material of the pump should be resistant to high temperature and corrosion, and its strength and service life should be considered. The gas released by molten salt decomposition at high temperature is more corrosive. Taking the common binary molten salt as an example, the operating temperature of the trough molten salt power station and the tower molten salt power station are different. The operating temperature of the trough molten salt heat storage system is between 220 ℃ and 400 ℃. According to this temperature, 304 and 316 stainless steel can be selected as the material of the molten salt pump; For tower type molten salt power station, the working temperature of molten salt is between 220 ℃ and 550 ℃, and 316, 347 stainless steel or 718 chromium-nickel alloy steel that is more resistant to high temperature and corrosion is required.
The high-speed flow of molten salt will also cause rapid corrosion of the impeller blades of the molten salt pump. The corrosion damage rate is proportional to the medium flow rate. The higher the flow rate, the faster the corrosion rate. Therefore, the flow rate of molten salt should be properly controlled within the safe range.

Take you to understand the use of vacuum pump filter

15 problems in daily maintenance of centrifugal pump

 

The centrifugal pump works by centrifugal movement of water when the impeller rotates. Before starting the pump, the pump casing and suction pipe must be filled with water, and then the motor can be started to drive the pump shaft to drive the impeller and make the water perform high-speed rotation. The pressurized water line into the pump.
1. Check whether the pump vibrates abnormally. If vibration occurs, stop the pump immediately for inspection.
2. Check whether the bearing temperature is normal. Too high temperature will accelerate bearing damage and shorten the service life of the pump.
3. Check whether the lubricating oil level is normal. If the lubricating oil expires, it needs to be replaced frequently.
4. Check whether the lubricating oil temperature is normal
5. Check whether the lubricating oil is qualified
6. Check whether the leakage meets the requirements. For serious leakage, please check whether the mechanical seal is damaged.
7. Check whether the sealing fluid operates normally
8. Check whether the sealing cooling medium is normal
9. Check whether the cooling water system is normal
10. Check whether the grounding of the motor is intact. Please pay attention to whether the grounding bolt is loose and tighten it in time.
11. Check whether the motor vibration is normal
12. Check whether the motor bearing temperature is normal
13. Check whether the motor current is normal. If the current is too high, the centrifugal pump will not work properly.
14. Check whether the pump inlet pressure is normal and stable
15. Check whether the pump outlet pressure and flow are normal and stable

Vacuum Pumps for Food Packaging Machines

How to reduce the energy consumption of centrifugal pump?

 

The efficiency of centrifugal pump is the product of mechanical efficiency, volumetric efficiency and hydraulic efficiency. The efficiency of single-stage centrifugal pump unit is the product of pump efficiency and motor efficiency. How to reduce energy consumption and improve efficiency of centrifugal pump?
1. Application of frequency conversion energy-saving technology. For centrifugal pumps whose design parameters are greater than the actual working conditions, the centrifugal pump will always operate in the high efficiency zone after installing the variable frequency speed control device.
2. Promote the application of high-efficiency energy-saving permanent magnet motor, dual-power motor and other energy-saving new products on the main centrifugal pump.
3. Selection of centrifugal pump. When selecting a new pump, the pump produced by a large manufacturer should be selected to ensure the high efficiency of the centrifugal pump.
4. Maintenance of centrifugal pump.
(1) Frequently check and adjust the shaft end seal of the centrifugal pump to reduce the volume loss;
(2) After 10000 hours of operation, the centrifugal pump should be overhauled to restore the efficiency of the pump;
(3) Applying bellows sealing technology to centrifugal pump can completely eliminate the leakage of centrifugal pump and improve the volumetric efficiency.
5. Clean the filter cartridge regularly, check the pipe connection, and ensure that the inlet pipe of the centrifugal pump is smooth.
6. In strict accordance with the operating regulations of centrifugal pump, before starting the pump, the disc pump must be started, the inlet valve must be opened, the outlet valve must be closed, the exhaust and exhaust must be conducted, and the inlet pressure of the pump must be checked to see if it meets the requirements. Prevent pump cavitation caused by low supply pressure and insufficient flow.
7. Regularly check the pump efficiency of the centrifugal pump, find out the cause of low pump efficiency in time, and take corresponding measures to solve it.

dry screw vacuum pump of reasons for lack of air volume