Why Choose YOUNAI BB4 Pumps
- High efficiency, optimized hydraulic passages;
- Low NPSH, first-stage anti-cavitation impeller design;
- Wide hydraulic coverage, extensive BB4 Pump range;
- Multiple materials & seal configurations;
- Flexible inlet and outlet orientations;
- Customized configurations available for high-temperature duties.
What Is the BB4 Pump?
The BB4 Pump, also referred to as a ring section pump, sectional diffuser pump, or radially split pump, is a horizontal, multi-stage centrifugal pump built around a modular ring-section construction.
Each stage of the BB4 Pump consists of an individual cylindrical casing section housing a single impeller and diffuser. Fluid enters axially through the suction nozzle and passes through each successive stage at increasing pressure. The total head delivered is determined by the number of stages, making the BB4 Pump inherently scalable to a wide range of pressure requirements.
This construction defines the BB4 Pump’s character: lightweight, compact overall dimensions, and a modular structure that translates directly into practical advantages at every stage of the pump’s life, from installation and commissioning through to routine maintenance.
YOUNAI manufactures the BB4 Pump across an extensive product range. By varying impeller diameter and stage count, our BB4 Pumps cover a broad hydraulic envelope, ensuring the pump you select operates at or near its Best Efficiency Point (BEP) for your specific duty. The range extends across general industrial, municipal, and process industry applications. For oil & gas and petrochemical services, YOUNAI also offers BB4 Pumps designed in accordance with API 610 standards, with a proven track record in these demanding applications.
YOUNAI BB4 Pumps
An extensive BB4 Pump range, covering a broad hydraulic envelope to suit the full spectrum of industrial high-pressure duties. Each model is engineered to match specific operating conditions, select the right BB4 Pump for your application below.
Max. flow rate: 1,680m3/h
Max. head: 1,250m
High-capacity
Balance drum / balance disc
Max. flow rate: 1,200m3/h
Max. head: 1,050m
Opposed impeller arrangement
Inherent axial thrust balance
Max. flow rate: 880m3/h
Max. head: 1,100m
SS304/316/316L/2205/2507/904L
Max. flow rate: 1,200m3/h
Max. head: 1,050m
Max. Temperature: 245℃
Centerline mounting, thermal-expansion tolerance
Optimized Hydraulic Design for Maximum Efficiency
Greater hydraulic efficiency directly reduces energy consumption and long-term operating costs.
Our BB4 pump is hydraulically optimized to deliver high efficiency across the operating range. Advanced hydraulic design minimizes hydraulic losses and improves energy conversion efficiency. YOUNAI offers an extensive BB4 pump range with multiple impeller diameters and stage combinations, ensuring broad hydraulic coverage for diverse applications. This wide product portfolio allows us to match the pump more precisely to your specific operating conditions, enabling operation near the Best Efficiency Point (BEP) for maximum efficiency and lower operating costs.
Stable hydraulic performance with consistently high efficiency under continuous operation.
Precision Manufacturing
The performance of a BB4 centrifugal pump is determined by the dimensional accuracy of its hydraulic components. YOUNAI manufactures BB4 Pumps to tight tolerances throughout:
- Impellers are precision-cast and shrink-fitted to the shaft, eliminating fretting and residual mechanical unbalance;
- Diffusers and return channels are cast to close dimensional tolerances and machine-finished for hydraulic conformity;
- Shaft and bearing assemblies are inspected and verified to ensure smooth rotation and low vibration characteristics prior to delivery.
This manufacturing approach ensures consistent rotor stability and contributes to low vibration levels and reliable long-term operation.
Engineered for High-Temperature, High-Pressure Service
For duties above 150°C, we recommend the centerline supported base plate design, which eliminates coupling misalignment, reducing unexpected shutdowns and maintenance.
The BB4 Pump’s lightweight, single-casing construction means lower thermal mass, allowing faster startup and faster attainment of full operating load, qualities that remain essential in high-temperature service. Reliable high-temperature operation also depends on the correct seal system and the use of materials such as alloy steel and chrome steel.
At YOUNAI, we understand that selecting the right pump for complex high-temperature, high-pressure duties demands careful engineering judgement, not simply matching datasheets. Our engineering team works through the technical trade-offs with you to identify the right solution, however challenging or time-consuming that process may be.
Beyond Standard Materials
Most BB4 Pump applications involve water or hot water duties, where cast iron and carbon steel deliver proven, cost-effective performance. YOUNAI manufactures these standard configurations to the same high standards — reliable, competitively priced, and field-proven across a wide range of industrial services.
But where the duty demands more, YOUNAI goes further. For high-pressure transfer of corrosive and chemically aggressive fluids, material selection becomes as critical as hydraulic design. YOUNAI BB4 Pumps are available in a carefully selected range of corrosion-resistant alloys to match the specific demands of each service:
- Chrome steel — improved hardness and wear resistance for mildly abrasive services
- Duplex stainless steel (2205) — outstanding resistance to pitting, crevice corrosion, and stress corrosion cracking
- Super duplex stainless steel (2507) — the preferred choice for seawater, aggressive chemicals, and the most corrosive high-pressure services
- Titanium — exceptional resistance to chloride corrosion, nitric acid, hypochlorite, and other aggressive chemical media, making it the material of choice for seawater, brine, and chlor-alkali high-pressure services.
YOUNAI combines advanced manufacturing processes with rigorous material-specific testing and inspection to manufacture corrosion-resistant BB4 pumps with exceptional reliability and service life. BB4 pumps built with duplex stainless steel, super duplex stainless steel, and titanium materials have a proven track record across a wide range of demanding services worldwide and trusted where corrosion resistance and long-term reliability are non-negotiable.
Applications of BB4 Pumps
BB4 pumps are a proven solution across a wide range of industrial and municipal duties. Combining broad hydraulic coverage, material flexibility, and customizable configurations, they are a reliable choice for high-pressure applications.
The BB4 boiler feed pump delivers consistent, controlled pressure across a range of capacities. Available in standard and high-temperature configurations to suit the operating conditions.
The BB4 high-pressure pump provides reliable feed to reverse osmosis membrane systems. Low NPSHr and stable pressure output protect membrane integrity and contribute to lower operating costs over the system’s life.
The BB4 sectional pump’s robust construction and broad flow range suit it to mine water handling applications. With appropriate material and seal selection, it handles fluids containing suspended solids reliably.
The BB4 ring section pump is widely used for high-pressure water supply across manufacturing facilities, process plants, and large-scale municipal water systems.
Compact footprint and lightweight construction, designed for trailer-mounted fire pump packages with diesel engine and control cabinet, delivering high mobility and meeting high-head requirements in industrial fire protection service.
For high-pressure fluid transfer across a broad range of process duties, the BB4 multi-stage pump’s hydraulic range, material flexibility, and practical construction make it a dependable and cost-effective choice.
A BB4 radially split pump has its casing split perpendicular to the shaft axis, with each stage forming an independent ring section. This contrasts with a BB3 pump, where the casing splits along the shaft axis — resulting in a thicker, larger, and heavier construction with higher procurement costs. A BB5 pump uses a double-casing barrel construction, suited to the highest pressure duties, but with significantly greater mechanical complexity.
The BB4 centrifugal pump handles clean water, salt water, mildly corrosive chemicals, hot water, and fluids with light particle content. Each application requires appropriate selection of casing materials and seal system to suit the specific fluid and operating conditions.
Yes. For oil & gas and petrochemical duties, YOUNAI offers BB4 Pumps designed with reference to API 610. These pumps have been successfully deployed in high-pressure transfer services across petroleum, petrochemical, and natural gas facilities, with proven performance in continuous industrial operation.
NPSH (Net Positive Suction Head) is the amount of suction energy required for a pump to operate without cavitation. Through optimized hydraulic design, YOUNAI BB4 pumps achieve low NPSHr values, improving reliability under limited suction conditions and reducing the risk of cavitation. For applications with increased cavitation potential, bronze impellers can be supplied to provide enhanced resistance to cavitation damage and erosion.
Thanks to our standardized modular design and semi-finished component inventory, standard BB4 Pump configurations are typically delivered within 6 weeks. For special materials such as duplex stainless steel (2205) or super duplex (2507), lead times will be longer and are confirmed at the time of order. Spare parts are available for all BB4 Pump configurations throughout the product’s service life, contact our team for availability and delivery on specific components.
Yes. Based on the installation drawings you provide, we can evaluate whether our BB4 pump can directly replace your existing unit. In most cases, a direct replacement is possible. Where modifications are required, we can usually minimize changes to the existing piping and foundation while still achieving the desired upgrade or replacement.
Yes. The BB4 pump’s modular ring-section construction allows each stage to be individually disassembled and serviced, and only the damaged stage needs to be removed for repair or replacement. While the process still requires full dismantling of the pump, the BB4 places significantly lower demands on maintenance engineers compared to BB3 and BB5 pumps, which typically need to be returned to the factory for overhaul, a process that is both time-consuming and resource-intensive.
