Understanding Pump Classifications
What Are Traditional Pumps
Traditional pumps explain a general category of mechanical machinery designed to move fluids using mechanical forces. A few examples are positive displacement pumps (piston, diaphragm, and gear pumps) and other non-centrifugal pumps. Traditional pumps transport fluid by sealing a volume of fluid and displacing it through the discharge piping. Traditional pumps are often used in applications where precise control of flow or high pressure is needed, especially when the fluids are viscous or particulate-laden.
Definition of Centrifugal Pumps
Centrifugal pumps are dynamic pumps that employ rotational energy of motion in order to transport fluids. Fluid enters the pump’s impeller along or near the axis of rotation and is forced outward by the centrifugation force through the vanes of the impeller into a diffuser or volute casing. Longgang Pump mainly produces BB series, OH series, and VS series chemical centrifugal pumps, which have extensive uses in the petroleum, petrochemical, coal chemical industry, environmental protection, and water treatment industries.
Comparison of Working Principles
How Old Pumps Work
Traditional positive displacement pumps work through mechanical displacement of fluid using pistons or diaphragms. In each stroke, a volume of liquid is displaced, irrespective of system pressure. The result is a smooth flow but has pulsating delivery. These pumps are suitable for high-viscosity fluids or when precise dosing is required.
Centrifugal Pump Working Mechanism
Centrifugal pumps work on the basis of transferring velocity to the fluid using a rotating impeller. Fluid is fed to the center of the impeller and is flung to the periphery by centrifugal force, gaining kinetic energy which is converted into pressure energy in the volute casing. For example, Longgang LZV(OH3) single-stage vertical pipeline centrifugal pump utilizes a volute-shaped structure with a double volute design for outlets ≥80mm in order to resist radial forces efficiently and ensure rotor stiffness.
Performance and Efficiency Analysis
Flow Rate and Pressure Stability
Traditional pumps offer highly stable flow rates even under varying pressures due to their fixed displacement nature. However, they may experience pulsation unless dampeners are installed. Centrifugal pumps provide smooth flow, but their output can vary with system resistance.
Longgang’s BB2(LBD) heavy-duty centrifugal process pump features a double volute structure that reduces radial forces and extends bearing life, ensuring stable operation even under high pressure.
Energy Consumption Differences
Positive displacement pumps can be less energy-efficient when operating at partial loads or against high backpressure. In contrast, centrifugal pumps tend to be more energy-efficient when operating near their best efficiency point (BEP). The independently developed BB2 efficient centrifugal pump by Longgang reaches a hydraulic optimum efficiency point of 90.5%, which is 3.5% higher than the national first-level energy efficiency.
Application Suitability
Use Cases for Traditional Pumps
Traditional positive displacement pumps are suited for applications requiring constant flow regardless of head conditions—such as metering systems, chemical injection, and handling viscous materials like sludge or oils.
Longgang Centrifugal Pump Applications
Longgang’s centrifugal pumps serve across multiple sectors, including petrochemical refining units, coal gasification plants, power generation facilities, seawater desalination projects, and environmental engineering systems. For instance, the LY(VS4) long-axis submerged pump is widely used in refineries, sewage treatment plants, and cement factories—ideal for transporting clean or particle-containing corrosive media.
Product Design and Maintenance
Structural Differences in Pump Design
Traditional pumps typically have more complex internal moving parts, like valves or diaphragms, that require tight tolerances. Centrifugal pump designs are generally simpler with fewer moving parts—mainly involving an impeller mounted on a shaft within a casing.
The LZV(OH3) vertical pipeline pump includes throat bushings on both sides of the impeller for axial force balance and uses a center-supported volute casing to enhance mechanical stability.
Maintenance Requirements and Lifespan
Positive displacement pumps may need frequent maintenance due to wear on valves or seals from high-pressure operations. Centrifugal pumps usually offer longer service intervals when operated within design parameters.
Longgang emphasizes easy maintenance—many models allow bearing and seal replacement without disassembling piping connections. We executes a 12/18 months quality warranty with lifetime service support for all sold products.
Longgang Centrifugal Pump Product Highlights
LZV(OH3)-Single Stage Vertical Pipeline Centrifugal Pump
This model features excellent hydraulic design with anti-cavitation performance and long service life. It supports applications such as urban water supply, fire pressurization systems, long-distance pipeline transport, and petrochemical processes.
LY(VS4)-Long Axis Submerged Centrifugal Pump
Designed according to API610 standards, this model offers multi-point support structures for improved rotor stability under deep submersion conditions. It supports various sealing options, including dry gas seals for safe transportation of hazardous media.
Material and Build Quality
Materials Used in Traditional Pumps
Traditional positive displacement pumps often use cast iron or stainless steel components, depending on media compatibility, but may lack advanced material coatings for aggressive chemicals.
Longgang’s Anti-Corrosion Material Advantages
In addition to chemical pumps made of ordinary anti-corrosion materials, Longgang has developed special alloy material pumps, such as anti-dilute sulfuric acid, hydrochloric acid, and concentrated sulfuric acid-resistant duplex stainless steel models—ensuring durability in extreme environments.
Cost Considerations Over Time
Initial Investment vs Long-Term Cost
While traditional positive displacement pumps may have lower upfront costs for small-scale installations, they incur higher maintenance costs over time due to wear-prone components.
Centrifugal models like those from Longgang offer better lifecycle value due to efficient operation and reduced downtime needs.
Operational Savings with Longgang Pumps
The CO2 pipeline booster pump developed by Longgang successfully operated at 100% localization level, achieving stable performance under 10 MPa pressure while reducing carbon emissions—showcasing significant operational savings through advanced design innovations such as self-balancing structures and composite drag-reduction technology.
FAQ
Q: What distinguishes a centrifugal pump from other types?
A: A centrifugal pump uses rotational kinetic energy from an impeller to move fluids efficiently at variable flows depending on system resistance; unlike traditional positive displacement models that deliver fixed volumes per cycle.
Q: Are centrifugal pumps suitable for corrosive chemicals?
A: Yes. Longgang has developed customized alloy-based centrifugal chemical pumps resistant to hydrochloric acid and concentrated sulfuric acid—ideal for highly corrosive environments.
Q: What industries benefit most from centrifugal pump usage?
A: Industries such as petrochemical processing, power generation, and water treatment plants benefit significantly due to their need for continuous high-volume fluid handling at varying pressures.
