Understanding the Basic Differences
What Is a Single Stage Pump?
Single single-stage pump is a centrifugal pump powered by a single impeller to drive fluid. It is a relatively low-head pump with relatively straightforward design, hence applied in low to moderate head services. Longgang’s LZA (OH1) single-stage cantilever pump, for example, is applied in pumping clean or lightly particle-contaminated liquids, neutral or highly corrosive, in the range of -40℃ to +200℃ temperature. The pumps are foot-mounted and offer convenience in maintenance as they are pull-out types.
What Is a Multi-Stage Pump?
Unlike this, a multi-stage pump consists of two or more impellers mounted on a common shaft. These are in series with one another and add pressure in steps. The LTD (BB5) double shell multi-stage pump is a classic example of such a pump—it consists of a number of impellers in the same direction inside a segmented frame, offering high head capacities to 3000m and pressure ratings to 30 MPa.
Key Performance Comparison
Pressure and Flow Ratings
Single-stage pumps are typically utilized in applications requiring lower pressure but higher flow rates. For example, the LDTV (VS1) vertical suspended single shell pump offers flow ratings up to 2600 m³/h and heads up to 1400m, thus being ideally suited for medium-pressure applications.
Multi-stage pumps suit high-pressure applications where significant head is required. The LTD (BB5) design can supply heads of up to 3000m and is usually fitted on power plants, refineries, and offshore platforms where high-pressure delivery is required.
Energy Efficiency in Operation
Multi-stage pumps tend to be more energy-efficient when high head is needed because they distribute the workload across several impellers. This reduces energy loss per stage and improves overall system efficiency. For instance, Longgang’s BB2 efficient centrifugal pump reaches a verified hydraulic optimum efficiency point of 90.5%, which is 3.5% higher than the national first-level energy efficiency.
Installation and Maintenance Needs
Single-stage pumps are easier and quicker to install due to their simpler structure. Maintenance costs are also generally lower. Longgang’s LZE (OH2) single stage cantilever pump features an overall pull-out design that allows inspection without removing inlet or outlet pipelines.
Multi-stage pumps require more space and time for installation and maintenance, but offer longer service life in demanding conditions due to their robust construction.
Choosing Based on Application Scenarios
Suitable Uses for Single-Stage Pumps
Single-stage centrifugal pumps are ideal for straightforward liquid transfer tasks such as water supply systems, chemical processing of non-viscous fluids, and general industrial use. Longgang’s LZV (OH3) vertical pipeline pump is widely used in urban water supply, fire pressurization, and petrochemical industries due to its compact design and efficiency.
When to Use Multi-Stage Pumps
Multi-stage pumps are best suited for high-pressure applications like boiler feedwater systems, offshore oil transportation, seawater desalination, or any process requiring precise pressure control over long distances. For example, the LCD (BB3) horizontal split multi-stage pump can reach heads of up to 1600m and is used in power plant boiler feedwater systems and chemical industry high-pressure processes.
Longgang Product Recommendations
LTD(BB5)-Double Shell Multi-Stage Centrifugal Pump
This horizontal center-supported double-casing segmented pump features multiple impellers arranged in the same direction. It supports customized configurations, including first-stage single or double suction impellers and various bearing types like ZH sliding bearings or ZQ forced lubrication bearings. It’s ideal for transporting clean or particle-laden liquids under extreme pressure and temperature conditions.
LDTV(VS1)-Vertical Suspended Single Shell Centrifugal Pump
This API610 VS1-compliant vertical suspended centrifugal pump is designed with a center discharge structure. It supports thin oil lubrication with multi-point support bearings and includes monitoring ports for temperature and vibration. This model suits petrochemical environments requiring vertical installation with limited floor space.
Factors to Consider Before Buying
Required Head and Flow Rate
For low head (<250m) but high flow applications (>200 m³/h), a single-stage pump like Longgang’s OH series may suffice. For heads exceeding 500m or involving long-distance transport lines, consider multi-stage models such as the BB4 or BB5 series.
Fluid Type and Viscosity
If your application involves corrosive chemicals or slurries with trace particles, material compatibility becomes essential. Longgang has developed special alloy material pumps, such as anti-dilute sulfuric acid or hydrochloric acid variants, using super-low carbon duplex stainless steel. Customized sealing systems can also be configured based on fluid characteristics.
Space, Budget, and Maintenance Resources
Choose single stage pumps when space is limited or budget constraints exist, since they offer easier installation and lower maintenance costs. For critical infrastructure where reliability outweighs cost concerns—such as offshore oil platforms—multi-stage designs provide better performance longevity.
For tailored solutions that meet your exact requirements—including customized material selections, sealing systems, dimensions, flange standards—contact Longgang Pump at info@longgangpump.com or call +86 18865532020 today. We offer full lifecycle services from design consultation through after-sales support backed by ISO9001/API certified quality management systems. We provide free technical support within and outside the quality warranty period.
FAQ
Q: What is the main advantage of a multi-stage pump over a single-stage pump?
A: Multi-stage pumps can generate significantly higher pressures by using multiple impellers in series while maintaining energy efficiency. This makes them ideal for long-distance transport or high-head requirements.
Q: Can I use a single-stage pump for high-pressure applications?
A: Generally, no; single-stage pumps are not designed for very high heads. However, models like Longgang’s LZE (OH2), which supports pressures up to 10 MPa, can be considered if your pressure requirements fall within this range.
Q: How do I choose between LGIS and LGCZ single-stage pumps?
A: The selection depends on your specific application needs, such as required flow rate, head range, fluid type, temperature limits, installation orientation (horizontal vs vertical), and available space. Contact our technical advisory team for customized recommendations based on your working conditions.
Q: Are Longgang pumps resistant to corrosion from chemicals?
A: Yes. Longgang has developed chemical pumps made of special alloy materials, including super-low carbon duplex stainless steel that resists aggressive media like dilute sulfuric acid or hydrochloric acid. Customized sealing options further enhance corrosion resistance depending on your operational environment.
