Multi-stage  canned motor pumps

Multi-stage tandem type DCMC

Branch：DN25~DN200

Capacity：Max.700 m3/h

Head: max. 700m

Speed: 1450 to 3500 rpm

Operating temperature:Max. 160℃

Viscosity: max. 100mm²/s

Pressure rating: 2.5~16Mpa

Structural characteristics：

● BB5, barrel casing,multistage,ring section design

● On the basis of the muli-stage stangard type design, the pressure barrel casing is added to reduce the sealing points and make it safer.

● A pump of non-self priming type ,up to 12 stage.

● It makes internal high-pressure circulation, and the motor is cooled and the slide bearing lubricated by the medium being delivered.

● Tandem pressurized.

● With a low capacity,ahigh head,ithasan extremely lowNPSH.

Working principle

Canned motor pump is a combination unit of centrifugal pump and 3-phase AC motor, with the hydraulic section connection directly with the motor drive shaft to constitute the rotor component jointly. The stator can is embedded on the inner side of the stator to isolate both the rotor chamber and stator chamber,  that makes pumps no leakage completely.

Characteristic of canned motor pump

● Efficient with an European excellent hydraulic model.

● The stator can is in imported Hastelloy C276,a high magnetic permeability and a strong resistance to corrosion.

● The slide bearing is in crystal silicon carbide（SSIC）to have a high strength, a good resistance to wearing, corrosion and a service life 10 times more than graphite bearing.

● The canned motor is a 3-phase squirrel cage type induction motor,with a high efficiency, protection class IP55,explosive-proof class deⅡCT3~T5.

● The axial force is balanced automatically and hydraulically.

● In a simple and compact modular structure,it is easy for installation andmaintenance.

● In comparison with those pumps with mechanical seals, the MTBF(Mean Time Between Failure)is longer,the wearing and maintenance rate lower and the total operating cost less.

● Low noise.

Standardized chemical process pump:
Flow rate: up to~600 m ³/h
Head: up to 200 meters
Small magnetic drive pump:
Flow rate: usually less than 50 m ³/h
Head: usually less than 100 meters
Multi stage shielded pump:
Flow rate: The common range can reach up to 400 m ³/h
Lift: It can reach over 2000 meters, which is its main series for achieving ultra-high lift.
Ultra low temperature shielded pump for LNG:
Flow rate: Depending on specifications, it can be very large (for large-scale LNG transportation).
Head: Designed according to requirements, high pressure can also be achieved.

Working principle

Hermetic canned motor pump is a combination unit of centrifugal pump and 3-phase AC motor, with the hydraulic section connecting directly with the motor drive shaft to constitute the rotor component jointly. The stator can is embedded on the

inner side of the stator to isolate both the rotor chamber and stator chamber, that makes Hermetic pumps sealless completely.

Characteristics of canned motor pump

1.Efficient with an European excellent hydraulic model
2.The stator can is in Hastelloy C4 imported from Germany, that is formed by rolling in a special process to have a highprecision, a good quality free from welding defects, a high magnetic permeability and a strong resistance to corrosion
3.The slide bearing is in crystal silicon carbide (SSIC, SIC30) to have a high strength, a good resistance to wearing, corrosion and a service life 10 times more than graphite bearing
4.The canned motor is a 3-phase squirrel cage type induction motor, with a high efficiency, protection class IP55,

explosive-proof class de Ⅱ CT3~T5
4.The axial force is balanced automatically and hydraulically
5.In a simple and compact modular structure, it is easy for installation and maintenance
6.In comparison with those pumps with mechanical seals, the MTBF(Mean Time Between Failure) is longer, the wearing

and maintenance rate lower and the total operating cost less
7.low noise

The core feature of a canned pump is to integrate the motor and pump body into a completely sealed pressure vessel, with the motor rotor in direct contact with the conveyed medium, and the stator winding of the motor isolated from the medium through a shielding sleeve. It achieves static sealing and has no leakage during operation.

Vertical typeCZF-V Capacity ： ~800m3/h  Head: max. 260m Operating temperature: -100 o C~+100 o C  Viscosity: max. 100mm 2 /s  Pressure rating: ~6.3Mpa  Structural characteristics ：  ● A pump of vertical type, with a single stage.  ● It makes internal high-pressure circulation without external piping ,and the motor is cooled and the slide bearing lubricated by the medium being delivered.  ● It is used to deliver those media low viscosity, at a temperature not more than the specified highest temperature at the motor suction, free from particles and with a low melting point.    Working principle Canned motor pump is a combination unit of centrifugal pump and 3-phase AC motor, with the hydraulic section connection directly with the motor drive shaft to constitute the rotor component jointly. The stator can is embedded on the inner side of the stator to isolate both the rotor chamber and stator chamber, that makes pumps no leakage completely.  Characteristic of canned motor pump ●  Efficient with an European excellent hydraulic model.  ●  The stator can is in  imported  Hastelloy C 276, a high magnetic permeability and a strong resistance to corrosion.  ●  The slide bearing is in crystal silicon carbide （ SSIC ） to have a high strength,    a good resistance to wearing,  corrosion and a service life 10 times more than graphite bearing.  ●  The canned motor is a 3-phase squirrel cage type induction motor,with a high efficiency, protection class IP55,explosive-proof class de Ⅱ CT3~T5.  ●  The axial force is balanced automatically and hydraulically.  ●  In a simple and compact modular structure,it is easy for installation and maintenance .  ●  In comparison with those pumps with mechanical seals, the MTBF(Mean Time Between Failure)is longer,the wearing and maintenance rate lower and the total operating cost less.  ●  Low noise.

HERMETIC is a top brand in the global field of leak free pumps. Its magnetic pumps, with their zero leakage and high safety features, mainly serve high-end industrial sectors that have strict requirements for reliability, environmental protection, and extreme working conditions.

According to search results, the application industry of Haimitike magnetic pumps covers a wide range, and its core advantage lies in providing key fluid transportation solutions for strategic industries such as chemical, petrochemical, and nuclear power.

The following is a detailed overview of its main application industries:

Application Industry Specific Applications/Characteristics Key Customers/Remarks
🏭  Core application areas of chemical and petrochemical industries. Transporting flammable, explosive, highly toxic, or highly corrosive media such as acids, alkalis, solvents, and hydrocarbons to prevent leaks at the root and ensure production safety and the environment. Domestic and foreign giants: Sinopec, PetroChina, BASF, Bayer, Dow Chemical, DuPont, etc.
☢️  Nuclear power is used in nuclear grade fluid systems that require extremely high levels of sealing. The company has obtained the design and manufacturing license for civil nuclear pressure equipment issued by the National Nuclear Safety Administration, and its products serve domestic nuclear power plants. Provide critical equipment for nuclear power plants.
❄️  Refrigeration and low temperature are used to transport low-temperature or low boiling point media such as refrigerants, liquid ammonia, and fluorocarbons, ensuring efficient and leak free operation of the refrigeration system. Widely used, including industrial refrigeration and air conditioning systems.
🌱  New energy is applied in emerging fields such as photovoltaics and energy storage, providing reliable leak free fluid solutions for production processes. Debut at the International Photovoltaic Energy Storage Conference in 2024 to expand the new energy market.
💊  Pharmaceuticals and textiles transport solvents, intermediates, etc. during the pharmaceutical process to meet GMP requirements for cleanliness and safety; It is also used for transporting acid, alkali, and salt solutions in the textile and chemical fiber industry.     -
🚆  Rail locomotives are used for fluid systems such as cooling and lubrication in rail transit vehicles, meeting their high reliability and safety requirements.     -
💡  Core advantages and customer base
The reason why Haimitick magnetic pumps are able to enter these high-end industries lies in their technology originating from Germany and over 20 years of manufacturing experience from Sino German joint ventures. Its products (covering 21 series and 440 varieties) have become trusted long-term partners for global chemical giants such as BASF, Bayer, and Sinopec.

For specific applications in any of the above industries, if you would like to know more detailed selection plans or technical features, please feel free to let me know and I am happy to provide you with further answers.

Working principle description:

Occupying a leading position in the high-end and special working condition markets. Its products cover national strategic industries such as aerospace and nuclear power, as well as basic industries such as petrochemicals and clean energy.

Based on product characteristics and publicly available market information, its main application industries can be summarized into the following three major sectors:

🚀  National Strategy and High end Manufacturing
Having a high market reputation and rich performance in this field, it is the absolute leader in domestic market share.

Aerospace: The company is a long-term supplier of shielding pumps for the Xichang, Taiyuan, and Jiuquan satellite launch bases in China, providing critical support for the launch of the Shenzhou series manned spacecraft.

Nuclear power: The company has a design and manufacturing license for nuclear grade shielded electric pumps and is the main manufacturer in China that provides nuclear grade 3 shielded electric pumps to civilian nuclear power plants.

Rail Transit: Since 2007, its products have been widely used in the field of high-speed locomotives in China.

🏭  Petrochemical and Energy Industry
Has a large number of engineering application cases.

Petrochemical industry: The products are widely used in the medium transportation of various equipment such as refining, ethylene, caprolactam, polyoxymethylene, and polycarbonate.

Coal chemical industry: It has also been maturely applied in projects such as hydrogen production and urea based compound fertilizers.

Clean energy: It can provide LNG (liquefied natural gas) ultra-low temperature bucket bag pumps, which are applied in key links such as LNG receiving stations and liquefaction plants.

🏗️  General Industry and Livelihood Fields
In addition to the high-end fields mentioned above, Dalian Empire's products are also very popular in conventional industrial and living facilities.

Water treatment: Cooperate with companies such as Blue Water Technology to provide specialized pumps for seawater desalination, industrial wastewater treatment, and new energy wastewater treatment.

Refrigeration and air conditioning: As a traditional application field of shielded pumps, the product is widely used in refrigeration and air conditioning systems.

Chemical industry, shipbuilding, etc.: It is also widely used in general chemical industry, medicine, textile, shipbuilding and other fields.

Are you conducting preliminary research for a specific project, such as chemical engineering, water treatment, etc? Tell me the specific application scenario, and I can help you analyze the pros and cons of choosing a shielded pump under such working conditions.

Summary of Extreme Parameters
Parameter items can reach numerical values, applicable products/note sources
Maximum flow rate 1000 m ³/h low boiling point liquid conveying series [10]
Maximum head of 300m propane delivery pump (RW84 series) [8]
The maximum working pressure is 35 MPa, and the overall design capability of the company is [4]
20 MPa hydrogenation desulfurization device series [7]
Design pressure of 8.0 MPa caprolactam dedicated pump [4]
Maximum operating temperature 450 ° C hydrogenation desulfurization device series [7]
Minimum operating temperature -160 ° C grade ultra-low temperature LNG shielded pump [6]
Maximum power 560 kW API 685 standard ultra large shielded pump (2-pole water-cooled motor) [6]
Special monitoring THG (bearing monitoring), vibration, winding temperature, shielding sleeve damage monitoring for pumps used in hydrogenation desulfurization devices [7]
4、 Nuclear grade product qualification
Dalian Empire has obtained the design and manufacturing license for nuclear grade shielded electric pumps, providing shielded electric pumps to domestic civilian nuclear power plants and satellite launch bases, making contributions to satellite launches including the Shenzhou spacecraft.

5、 Summary of Technical Parameters
Typical products with core parameter boundaries at the application level
Petrochemical heavy-duty pressure 20-35 MPa, temperature 450 ° C, power 560 kW, hydrogenation desulfurization series, caprolactam dedicated pump
Low temperature refrigeration temperature -35 ° C to -160 ° C, flow rate 1000 m ³/h LNG dedicated pump, ammonia shielded pump, L-shaped air conditioning pump
Nuclear power/aerospace nuclear grade design and manufacturing license for pumps used in nuclear power plants and satellite launch bases

Power transmission: The stator of the motor is energized to generate a rotating magnetic field, which drives the rotor with a shielding sleeve to rotate. The rotor shaft directly drives the impeller to transport the medium.

Zero leakage guarantee: The stator winding and rotor core are respectively sealed and protected by the stator shielding sleeve and rotor shielding sleeve, completely isolated from the conveying medium. These two shielding sleeves are static, welded metal seals that fundamentally eliminate dynamic sealing points.

Cooling and lubrication: This is the key to the operation of the shielded pump. A small stream of high-pressure medium is drawn out from the pump outlet, passes through a filter, and sequentially flows through the rear bearing, the air gap between the motor rotor and stator, and the front bearing to lubricate the bearing and cool the motor. Finally, it returns to the low-pressure area at the pump inlet, forming a closed self circulating system.

2、 Detailed classification
There are various classification methods for shielded pumps, and the following are the mainstream classifications:

1. Classified by the arrangement of motors and pumps (the most basic classification)
Basic type: The most common. The motor is located behind the pump body, the bearings are located at both ends of the rotor, and the axial force is balanced by the impeller balance hole or thrust plate. Compact structure, the most widely used.

Reverse circulation type: The flow direction of the cooling circulation fluid is opposite to that of the basic type (from the front bearing to the rear). Suitable for easily vaporized media (such as liquefied gas), it can ensure that the pressure inside the pump is always higher than the vaporization pressure, preventing cavitation.

Reverse type: The motor is located at the front end (inlet side) of the pump body. This design can effectively prevent the accumulation of gas in the pump chamber, especially suitable for transporting gas containing liquids or easily crystallizable media.

High temperature type: A cooling jacket or external cooler is added outside the standard shielded pump to forcibly cool the circulating liquid to cope with high-temperature media (usually>150 ℃).

2. Classified by bearing type and monitoring
Sliding bearing type: absolutely mainstream. Sliding bearings made of self-lubricating materials such as graphite, silicon carbide, and hard alloy rely on medium lubrication.

Monitoring method:

Built in bearing wear monitor: detects the degree of bearing wear through electrodes, and automatically alarms or shuts down when the wear reaches its limit. This is the standard configuration for high-end shielded pumps.

Non monitoring type: Low cost, requiring regular maintenance and inspection.

Rolling bearing type (rare): Only appears in specially designed or extremely low power shielded pumps, with very few applications.

3. Classified by shielding sleeve material
Hastelloy shielding sleeve: with excellent corrosion resistance, especially suitable for chloride ion corrosion environments, it is the first choice for high standard chemical applications.

Stainless steel shielding sleeve: the most commonly used (such as 304, 316L), with low cost, suitable for most occasions without strong corrosive media.

Special metal shielding sleeves such as titanium and tantalum: used for specific highly corrosive media, with high cost.

Double layer shielding sleeve: Two layers of shielding sleeves are used on the stator or rotor, and a leakage detection hole can be set in the middle. Once the inner layer ruptures, the medium will flow out of the detection hole and trigger an alarm, providing dual safety protection for extremely dangerous media.

4. Classify according to the characteristics of the conveying medium
Ordinary type: Transport clean, low-temperature, and well lubricated liquids (such as water and light oil).

Easy to vaporize medium type: adopting special designs such as reverse circulation, transporting liquefied gas, propylene, liquid ammonia, etc.

High melting point medium type: equipped with insulation jacket or heat tracing system, transporting media such as sulfur, asphalt, resin, etc. that solidify at room temperature.

Mud/Particle Type: Using special bearing materials (such as hard alloy to silicon carbide), increased clearance, and filters, it can transport media containing small amounts of particles (but not for primary use).

4、 Key points for application selection
The medium comes first: it must be clean, have good lubricity, and a certain degree of conductivity (to form a bearing lubrication film). Absolutely prohibit dry running, idling, and interruption of flow.

Bearing monitoring is key: for important applications, it is essential to choose models with built-in bearing wear monitors, as this is the core guarantee to prevent "minor issues (bearing wear)" from evolving into "major disasters (motor burnout)".

Pay attention to cavitation issues: When transporting easily vaporized media, it is necessary to choose shielded pumps with special designs such as reverse circulation, and ensure sufficient device cavitation allowance.

Power limitation: Due to the thickness of the shielding sleeve and heat dissipation, the single machine power of traditional shielded pumps has an upper limit (usually<400kW), but high-power technology has also been developing in recent years.

In summary, shielded pump is a well-designed and highly integrated leak free pump. It occupies a unique position in the fields of refrigeration, heating, some chemical processes, and aerospace due to its high efficiency, low noise, and extremely high operational stability. The core of its selection and application lies in a deep understanding of its working characteristics that rely on self-lubricating cooling of the medium, and real-time monitoring of the bearing status.

Detailed explanation of application industry
1. HVAC and refrigeration industry
This is the largest and most classic application market for shielded pumps, almost becoming an industry standard configuration.

Chiller/heat pump unit: used to transport refrigerants (such as R134a, R1234ze), refrigerants (ethylene glycol solution/brine), and cooling water. Its zero leakage characteristic completely prevents refrigerant leakage and refrigerant loss, ensuring long-term efficient operation of the system.

Absorption chiller: the core power equipment for transporting lithium bromide solution, requiring high vacuum sealing, and shielded pump is the only choice.

Regional cooling/heating stations: widely used in the primary and secondary circulation of large energy stations, suitable for installation inside buildings due to their quiet and maintenance free characteristics.

2. Chemical and process industries
Mainly used for circulating relatively clean, valuable or dangerous process media.

Fine Chemicals and Pharmaceuticals: Transport high-purity solvents, monomers, intermediates, etc. to prevent pollution and leakage losses. Especially suitable for enclosed reactor jacket heat medium circulation (thermal oil).

Low temperature liquid transportation: transporting easily vaporized media such as liquefied petroleum gas, liquid ammonia, and liquid carbon dioxide. A reverse circulation shielded pump should be selected to prevent cavitation.

High temperature heat medium system: Transport high-temperature heat transfer oil such as diphenyl ether, used for heating reaction vessels, molds, etc. A high-temperature shielded pump with an external cooling jacket is required.

Light oil transportation: Transport light, volatile, and flammable materials such as benzene, toluene, and gasoline within the device.

3. New energy and power industry
Nuclear power plant: Nuclear grade shielded pumps are key equipment used to transport cooling water, boric acid solution, etc. for the primary and secondary circuits. Require absolute reliability, zero leakage, and the ability to withstand extreme conditions such as earthquakes. Usually equipped with multiple monitoring and protection systems.

Polycrystalline silicon/photovoltaic industry: used in the reduction and hydrogenation sections of silicon material production for the circulation and transportation of chlorosilanes such as trichlorosilane and tetrachlorosilane. The medium is flammable and explosive, with high value, and requires strict sealing requirements.

Ground source/water source heat pump system: used for water circulation on the underground heat exchange side, with quiet and maintenance free environmental requirements.

4. National Defense and Aerospace
Ship nuclear power plant: Similar to civilian nuclear power plants, it is used for the main coolant circulation pump and requires extremely high reliability and compactness.

Aerospace: Used for environmental control systems in aircraft or spacecraft (such as fuel hydraulic oil heat exchange cycles) and critical fluid transport in ground support equipment.

5. Other special fields
Ultra pure water system: used in the final polishing cycle of semiconductor or pharmaceutical ultra pure water systems, requiring no pollution or detachment.

Experimental and testing equipment: requires a small fluid circulation device that is quiet, vibration free, and leak free.

Food and Beverage Industry: Used for transporting clean fluids such as edible oil, syrup, alcohol, etc. on sanitary production lines, but it should be noted that they are not suitable for media containing particles.

Taboos and limitations of selecting shielded pumps
Understanding the "not applicable" scenarios of shielded pumps is equally important as understanding their application areas:

It is strictly prohibited to transport media containing solid particles: particles will quickly wear down graphite/silicon carbide bearings, causing pump failure. This is the most important limitation.

Strictly prohibit dry running and interruption: bearings rely on medium lubrication and cooling, and short-term dry running can cause catastrophic damage.

Be cautious when using high viscosity media: High viscosity media can affect the self circulating cooling effect and may cause the motor to overheat.

Not suitable for media with strong corrosiveness but poor lubricity: Even if the material is corrosion-resistant, poor lubrication can lead to rapid bearing wear.

Relatively limited power: Traditional structures are not as flexible as magnetic pumps in high-power applications (except for special cases such as nuclear main pumps).

Comparison of Application Selection with Magnetic Pump

Comparison of Application Selection with Magnetic Pump
Prioritize the selection of shielded pumps based on scene features and magnetic pumps
The cleanliness of the medium is clean, with no particles and may contain trace particles (selection required)
The requirement for good lubricity of the medium (such as water, light hydrocarbons) is relatively low
Operating mode: Long term continuous operation, either continuous or intermittent
Convenient maintenance: The motor is special and difficult to maintain on site. The motor standard is relatively easy to maintain
Typical industries include HVAC refrigeration, nuclear energy, some chemical cycles, general chemicals, pharmaceuticals, semiconductors, and electroplating
In summary, shielded pumps are the silent guardians in both closed-loop systems and clean processes. It has established an unshakable position in the fields of air conditioning refrigeration, nuclear energy, and specific chemical cycles. The key to its successful application lies in ensuring that the medium is like pure blood, steadily and quietly propelled by this highly integrated and leak free "heart" in a closed blood vessel (pipeline). Once the medium conditions deteriorate, this' heart 'will be very fragile. Therefore, correct selection and strict adherence to operating standards are the cornerstone of its long-lasting operation.

CANNED PUMP， In Chinese, it is commonly referred to as a shielded pump or unsealed pump, which is a revolutionary pump type that achieves absolute zero leakage.

The following is a detailed introduction to the shielded pump, covering its principle, structure, advantages and disadvantages, core applications, and comparison with other pump types.

1、 Core Definition and Revolutionary Characteristics
Essence: Shielded pump is a special centrifugal pump that integrates the motor and pump body, and has no dynamic rotating seal at all.

Revolutionary feature: It completely isolates the motor rotor and stator from the conveying medium through a thin-walled metal cylinder called a "shielding sleeve", while utilizing the medium itself for circulating lubrication and cooling. It fundamentally eliminates the biggest fault point and leakage source of traditional pumps - the shaft seal.

Design standard: In the industrial field, the most authoritative design and manufacturing standard is API 685 "Unscented Centrifugal Pumps for Petroleum, Petrochemical, and Natural Gas Industries", which is a supplement and specialization of API 610 standard for unsealed pumps. Functional description of key components:

Shielding sleeve: This is the "heart" of the shielded pump. Usually made of corrosion-resistant materials such as Hastelloy, very thin (about 0.1-0.3mm) to ensure efficient magnetic transmission. It needs to withstand system pressure while ensuring the electromagnetic efficiency of the motor.

Circulating circuit: This is the "lifeline" of the shielded pump. A small stream of medium (about 1-3% flow rate) is drawn out from the high-pressure area of the pump outlet, forced to flow through the rear bearing → the gap between the rotor and the shielding sleeve → the front bearing, and finally returned to the low-pressure suction port of the pump. This circuit has achieved:

Lubricating bearings: Graphite or silicon carbide bearings require medium lubrication.

Cooling motor and medium: Take away the heat generated by the rotor and bearings.

Eliminate bubbles: Ensure that the bearing area is always filled with liquid.

Bearings: typically made of impregnated resin graphite or high-performance silicon carbide (SiC). They rely on the transported medium for lubrication, so the lubricity and cleanliness of the medium are crucial. API 685 requires the configuration of a bearing wear monitor (such as a proximity probe), which is a critical safety configuration.

Heat exchange device: For easily vaporized or high-temperature media, the temperature of the circulating liquid may be too high. Therefore, shielded pumps are usually equipped with built-in heat exchangers (jackets) or connected to external cooling systems to dissipate heat and prevent medium vaporization.

3、 Core advantages
Absolute zero leakage: This is its biggest advantage. There is no rotating shaft seal, theoretically there is no possibility of leakage to the atmospheric environment. It is the only safe choice for handling highly toxic, carcinogenic, extremely hazardous, highly radioactive, and expensive media.

High safety: Avoiding the risks of fire, explosion, poisoning, and environmental pollution caused by seal failure.

High reliability/low maintenance: compact structure, no coupling, no need for centering. The main wear parts are bearings, which have a long service life under good working conditions. Maintenance work has been greatly reduced.

Suitable for easily vaporized media: Due to the same system pressure inside the pump chamber and motor, cavitation is not easily generated, making it very suitable for transporting liquefied gases (LPG, liquid ammonia, propylene, etc.).

4、 Main drawbacks and limitations
Low efficiency:

The shielding sleeve generates eddy current losses.

The loop consumes energy.

Friction loss of bearings.

The overall efficiency is usually 5% -15% lower than sealed pumps with the same parameters.

High cost: The structure is complex, the materials are special (shielding sleeve, bearings), the manufacturing process is precise, and the initial procurement cost is much higher than traditional pumps.

High requirements for media:

Must be clean: Solid particles will rapidly wear down graphite bearings and shielding sleeves.

Must have lubricity: Pure water and liquid hydrocarbons (such as propane) have poor lubricity and require special bearing design or lubrication measures.

Cannot be too viscous: High viscosity media affect circulation and cooling, which may cause overheating.

Complex maintenance: Once internal damage occurs (such as shield sleeve rupture or bearing jamming), it is necessary to return to the original factory or professional workshop for disassembly and major repairs, which cannot be easily handled on site.

5、 Comparison with magnetic pump
Both are "leak free pumps", but their principles are different and often confused.

Characteristic shielded pump magnetic pump
The principle is that the motor and pump are integrated, and the stator and rotor are isolated by shielding sleeves. Traditional motor+magnetic coupling utilizes the magnetic force of the outer and inner magnetic cylinders to penetrate the isolation sleeve and transmit torque.
More compact structure, without coupling. Longer, with external magnetic cylinder and internal magnetic cylinder.
Low efficiency (shielding sleeve vortex loss+cycle loss). Relatively high (but still with eddy current losses).
The load-bearing capacity of the rotor is immersed in the medium, and the bearing has a large load-bearing capacity, suitable for high power. The size of the inner magnetic cylinder bearing is limited and is usually used for small and medium power (generally<400kW).
Maintainable overall maintenance. On site replacement of isolation sleeves or bearing components is relatively convenient.
The cost is very high. Moderate to high.
Applicable standard API 685 (mainstream). API 685 or ASME B73.3M.
Simply put, shielded pumps are a "deep integration" solution that can achieve high power output; Magnetic pumps are a modular coupling solution that is more suitable for small and medium power applications.

6、 Core application areas (necessary occasions for use)
Shielded pumps are the preferred or mandatory requirement for the following harsh operating conditions:

Extremely dangerous medium:

Highly toxic/carcinogenic substances: phosgene, hydrogen cyanide, benzo [a] pyrene, etc.

Highly radioactive liquids: primary coolant and nuclear waste in nuclear power plants.

Extremely hazardous environmental media: PCB (polychlorinated biphenyls), potent insecticides, etc.

Highly flammable and explosive media: in situations where leakage may cause disasters, such as hydrofluoric acid alkylation units, ethylene, propylene, and liquefied natural gas transportation.

Valuable media: spices, expensive catalysts, platinum solutions, etc. Leakage can cause huge economic losses.

Strong corrosive/permeable media: fuming sulfuric acid, liquid chlorine, bromine, etc. These media can quickly damage any mechanical seal.

Aerospace: refueling and delivery of rocket fuel (such as dimethylhydrazine).

7、 Key points for selection and use
Compliance with standards: Industrial applications must specify the API 685 standard, which includes mandatory safety requirements such as bearing monitoring, shielding sleeve testing, and material selection.

Media analysis: It is necessary to have a clear understanding of the lubricity, cleanliness, corrosiveness, and saturated vapor pressure of the media.

Minimum continuous flow rate: Shielded pumps are limited by minimum continuous stable flow rate and minimum continuous heat flow rate. Operating below this flow rate will result in insufficient circulating cooling, medium vaporization, and bearing burnout. It is usually necessary to set up an automatic recirculation valve.

Monitoring system: Ensure the configuration of bearing wear monitors and circulation pipeline sight glasses, which are the eyes to ensure safe operation.

Backup plan: For critical workstations, even if the reliability of the shielded pump is high, 100% backup is often considered because its fault repair time is longer.

summary
Shielded pump is a special pump designed to solve the fundamental problem of leakage. It has achieved unparalleled safety and sealing reliability at a higher cost and slightly lower efficiency. It is not a universal pump, but a necessary engineering item for specific high-risk, high-value, and high demand working conditions. Shielded pumps play an irreplaceable and critical role in safety and environmental fields such as chemical, petrochemical, pharmaceutical, and nuclear industries.

Empire Shielding Pump, Japanese Machine Installed Shielding Pump, Haimitik Shielding Pump, Technical Features
Okay, this is a professional review and comparison of the technical characteristics of several mainstream brands of shielded pumps. Please note that the summary of these technical features is based on publicly available technical literature and market positioning from various brands, and there may be model differences in actual applications.
The following is a comparison of the core technical characteristics of the Imperial Shield Pump, Japanese Aircraft Shield Pump, and Haimitik Shield Pump:
1. Imperial Shield Pump
It usually refers to the products of Teikoku, the Japanese Imperial Electric Machinery Manufacturing Company, which is one of the pioneers and global leaders in the field of shielded pumps, known for its extremely high reliability and durability.
Core technical features:
Classic and durable design: The structure is classic and solid, with exquisite materials, pursuing ultra long service life and maintenance free under harsh working conditions. Many pumps that have been in operation for over 30 years are still in service.
Excellent rotor dynamics: With extensive experience in bearing design (such as lubrication grooves and cooling channels for graphite bearings) and rotor stator clearance control, we ensure smooth operation with extremely low vibration and noise.
Comprehensive material system: Provides the widest range of material combination options, including various special alloys, Hastelloy alloys, ceramics, etc., to adapt to extreme media such as strong corrosion, high temperature, and high pressure.
High precision manufacturing: requires extremely high precision in part processing, dynamic balance level, and assembly process, ensuring performance and consistency.
Suitable for critical processes: occupying a dominant position in fields such as petrochemicals, chemical engineering, and nuclear power that require extremely high safety and continuity.
Market positioning: High end, critical, and long-term process industrial applications. The price is higher, but the total cost of ownership (TCO) may be lower in the long run.
2. Daily installation of shielded pumps
Refers to the products of Nikkiso, a world-class brand known for its technological innovation and modular design.
Core technical features:
Innovative internal structure: such as its famous "eddy current" internal circulation system, it can more effectively cool motors and lubricate bearings, especially suitable for media that are prone to vaporization, high temperature, or contain particles.
Advanced monitoring and diagnosis: Early and deeply integrated state monitoring technology (such as bearing wear monitoring, temperature, vibration sensors), supporting predictive maintenance.
Modular and standardized design: The standardization level of components is high, and maintenance and spare parts replacement are relatively convenient. Introducing the "Cartridge" core package design, which allows for quick replacement of core components and reduces downtime.
Focusing on high difficulty media: has strong technological advantages in areas such as liquefied natural gas (LNG), low-temperature media, and high-purity chemical transportation.
Wide product line: covering chemical process pumps with small flow and high head to LNG conveying pumps with large flow.
Market positioning: leading technology, strong adaptability, emphasis on maintainability, widely used in chemical industry LNG、 Electronic chemicals, pharmaceuticals, and other fields.
3. Haimitik shielded pump
Hermetic, a German company, is a leading manufacturer of shielded pumps in Europe, known for its precision, efficiency, and customized capabilities for specific applications.
Core technical features:
Contactless' torque ring 'technology: This is its signature innovation. Introducing a "torque ring" between the motor rotor and the pump impeller, torque is transmitted through a magnetic field rather than a mechanical connection, achieving complete static sealing and zero leakage, eliminating dynamic sealing points, and ensuring extremely high safety.
Wear free operation concept: Thanks to the torque ring and non-contact design, the moving parts inside the pump are almost free of wear, with an extremely long theoretical life and low maintenance requirements.
High efficiency: The integrated optimization design of the motor and pump body results in high hydraulic efficiency and outstanding energy efficiency performance.
Suitable for high-purity and high-risk media: particularly adept at handling extremely dangerous, highly toxic, high-purity media that do not allow any pollution (such as polycrystalline silicon, electronic special gas, hydrofluoric acid, etc.).
Precision Engineering: Made in Germany with precision, high accuracy, smooth and quiet operation.
Market positioning: The preferred choice for applications with ultra-high safety, zero leakage, high purity, and long lifespan. Widely used in industries such as polysilicon, electronic semiconductors, specialty chemicals, and pharmaceuticals that have zero tolerance for leaks.

summary comparison
characteristic dimension
    
Empire Shield Pump
    
Japanese machine installed shielded pump
    
Haimitik shielded pump

Core advantages
    
Classic, reliable, and durable
    
Innovation, intelligence, and strong adaptability
    
Absolute safety, zero leakage, and high efficiency

Technical logo
    
Excellent rotor dynamics and bearing technology
    
Eddy current cooling system and condition monitoring
    
Contactless "torque ring" technology

Applicable working conditions
    
Traditional, demanding, and long-term processes
    
Processes containing LNG, prone to vaporization, and requiring monitoring
    
A process that is high-purity, high-risk, highly toxic, and absolutely not allowed to leak

Market positioning
    
The 'gold standard' of process industry
    
Technical solution provider
    
Experts with special safety and purity requirements

Cost considerations
    
The initial investment is high, but the lifecycle cost may be lower
    
Balancing technological value and maintenance costs
    
The initial investment is the highest, but payment is made for safety and purity
Suggestion for selection:
Traditional petrochemical and chemical key processes, pursuing decades of trouble free operation: Empire is the preferred choice.
LNG、 Easy to vaporize medium, hoping to achieve predictive maintenance: The advantages of daily installation are obvious.
Polycrystalline silicon, electronic chemicals, highly toxic media, and zero tolerance for leaks: Haimitik is the ideal choice.
The final selection needs to be comprehensively evaluated based on specific medium characteristics, operating parameters, budget, and project requirements