Nikkiso's canned motor pumps are characterized by their deep-rooted technological foundation as an industry pioneer and their extensive experience in handling extremely challenging conditions (such as high-temperature sulfur and strong acids). While Teikoku Pumps is known for its comprehensive and robust capabilities, Nikkiso is more representative in highly specialized, niche applications.

Core Characteristics: Technological Origins and High-End Applications

We can understand the characteristics of Nikkiso canned motor pumps from three aspects: technological origins, ability to handle extreme conditions, and market position.

Characteristics Dimensions | Core Characteristics | Brief Description and Technological Highlights

Technological Origins and Industry Position | Global Technological Pioneer Nikkiso Corporation is a globally recognized pioneer and leader in the canned motor pump field. Its profound technological foundation serves as a benchmark for the industry.

Patents and Innovation | As an industry pioneer, Nikkiso possesses numerous fundamental patents. Addressing the pain points of traditional canned motor pumps (such as bearing life and inability to transport liquids containing particulates), it has unique improved patented designs. For example, it uses oil-lubricated rolling bearings instead of traditional media-lubricated sliding bearings, significantly improving bearing life and reliability.

Canned LNG Pumps: Applications in the LNG Industry

(10 pages read)
The application of canned LNG pumps in the LNG (liquefied natural gas) industry is crucial, primarily due to their completely leak-free characteristics, perfectly matching the stringent requirements of LNG's cryogenic, flammable, and explosive properties. It can be said that they are an indispensable core piece of equipment in the LNG industry chain.

Below, I will outline the specific applications of canned LNG pumps in the LNG industry from three aspects: core application areas, the technical challenges addressed, and specialized pump structures.

I. Core Application Areas
From LNG receiving and storage to gasification and end-use, canned LNG pumps are present throughout almost the entire industry chain.

Application Stage | Specific Location/Purpose | Key Role

LNG Receiving Terminals and Peak Shaving Stations | Used to transport LNG from large storage tanks or provide stable pressure and flow for subsequent gasification processes. | Enables high-pressure, high-flow-rate LNG transportation.

LNG Plants | Within liquefaction plants, responsible for transporting cryogenic LNG between various process units. | Ensures the continuity and stability of the liquefaction production process.

LNG Plants LNG Transportation and Loading/Unloading: Used for unloading LNG from tank trucks to storage tanks, or for LNG loading and unloading operations on barges (terminals). Enables safe and rapid transfer of LNG.

End Users: Such as LNG refueling stations, used for refueling LNG vehicles. Ensures a safe, accurate, and leak-free refueling process.

II. Addressing Technical Challenges in LNG Applications: Safely and efficiently transporting LNG, a cryogenic liquid with a boiling point of -162℃, places extremely high demands on pumps. Canned motor pumps, through their unique design, successfully meet these challenges.

Challenge Dimensions | Specific Problems | Canned Motor Pump Solutions

Cryogenic Temperature and Materials: At extremely low temperatures of -162℃, ordinary materials become brittle and lose their toughness, potentially leading to pump body cracking. The pump's flow-through components and main structure are made of high-quality cryogenic stainless steel (such as austenitic stainless steel) to ensure good mechanical properties even at low temperatures.

Cavitation Issues: LNG is highly susceptible to vaporization. During pump operation, if the pressure is too low, LNG will vaporize and produce bubbles. When these bubbles burst, they can damage components such as the impeller, leading to decreased pump performance or even malfunction. A vertical structure is adopted, completely immersing the pump and motor in LNG. This method significantly shortens the pump's suction inlet length, reduces pre-cooling time, and reduces the probability of cavitation from the source. Simultaneously, the hydraulic design, including the helical guide impeller, further reduces the required net positive suction head (NPSH) and improves cavitation resistance.

Sealing and Safety: LNG is a flammable and explosive medium; even a small leak can cause a fire or explosion. This is the fundamental advantage of canned motor pumps. The static sealing structure eliminates the traditional rotating shaft dynamic seal, achieving zero leakage to the outside world and fundamentally eliminating safety hazards caused by media leakage.

Lubrication and Cooling: Effective cooling and lubrication of the pump's motor and bearings in low-temperature environments is a challenge. A portion of the LNG is cleverly used as a coolant and lubricant. Circulating LNG flows through the motor and bearings, carrying away the heat generated by the motor and lubricating the bearings. This LNG then eventually flows into the pump outlet or back to the storage tank, achieving efficient heat utilization and system self-cooling.

III. Key Specialized Pump Type: Reverse Circulation Canned Shielded Pump

In the LNG industry, the most commonly used type of canned pump is the reverse circulation canned pump. This is because it is specifically designed for easily vaporized media such as LNG.

Traditional Pump Pain Points: When transporting easily vaporized liquids, ordinary pumps (including basic canned pumps) experience a temperature increase in the circulating fluid used to cool the motor after absorbing heat. If this heated fluid flows back to the pump inlet, it can easily cause LNG vaporization, leading to cavitation.

Advantages of Reverse Circulation:

Unique Circulation Path: It directly discharges the heated circulating fluid, which has absorbed heat from the motor, back to the vapor phase zone of the upstream storage tank through a dedicated reverse circulation pipeline, instead of returning to the pump inlet.

Fundamentally Prevents Cavitation: This avoids interference from warming liquids on pump inlet conditions, ensuring that only low-temperature, unvaporized LNG enters the impeller, thus fundamentally preventing cavitation.

Automatic Venting: This structure also ensures that no gas accumulates in the motor cavity before pump startup, guaranteeing bearing lubrication and cooling, and eliminating the need for an additional vent valve on the pump itself.

Summary: In summary, canned motor pumps, with their zero-leakage safety, low-temperature resistant materials, excellent cavitation resistance, and reverse circulation structure specifically designed for easily vaporized media, perfectly meet the highest safety and reliability requirements of the LNG industry, making them the ideal choice for all stages of the LNG supply chain, from receiving and storage to end-use.

Are you selecting a canned motor pump for a specific LNG project (such as a receiving terminal, refueling station, or transportation and handling)? Tell me the specific flow rate, head, and other operating parameters, and I can help you further analyze how to select or match a suitable canned motor pump model.