Horizontal Double Suction Pump

Horizontal Double Suction Split Case Pumps 

High-Volume Industrial Fluid Solutions | Axially Split Casing | 20 Years of Field Expertise

FILIPUSI CW series horizontal double suction split case pumps are engineered for high-volume liquid transfer in power plant cooling water circulation, municipal water supply and drainage, industrial process cooling, and large-scale HVAC systems. The axially split casing design allows full access to the rotating assembly without disconnecting piping, significantly reducing maintenance downtime.

Available with flows from 50 to 20,000 m³/h and heads from 10 to 200 meters, the CW series delivers unmatched hydraulic efficiency and continuous operational reliability. The double-suction impeller balances axial hydraulic thrust, enabling vibration-free operation at extremely high flow rates with extended bearing and seal service life. Standard cast iron construction with stainless steel, bronze, or duplex options available for corrosive service.

Applicable to: Power Plant Cooling Water Circulation, Municipal Water Supply & Drainage, Industrial Process Cooling, Large-Scale HVAC & District Energy, Agriculture & Irrigation, Water Treatment Plants, Fire Protection Systems, and Flood Control Stations.

Core Advantages & Engineering Features

Operational Principle & Structural Characteristics

The FILIPUSI CW series horizontal double suction split case pump operates on the principle of dual-sided impeller feeding. Fluid enters the suction nozzle and splits into two streams, each flowing to one side of the double-suction impeller. This symmetrical inflow design cancels out axial thrust forces, allowing the pump to handle extremely high flow rates (up to 20,000 m³/h) with minimal vibration and extended bearing life. The axially split casing allows the upper half to be removed for complete internal inspection without disconnecting suction or discharge piping.

• Axially Split Casing Design: The pump casing is split along the horizontal centerline, allowing the upper casing half to be lifted off for complete access to the rotating assembly without disturbing pipeline connections.
• Double-Suction Impeller: Fluid enters from both sides of the impeller simultaneously, balancing axial hydraulic thrust and eliminating the need for thrust bearings in most configurations.
• Between-Bearings Design: The impeller is supported by bearings on both sides, providing exceptional shaft stability and allowing operation at high flows with minimal shaft deflection.
• Horizontal Centerline Mounting: The pump is mounted at the centerline of the casing, allowing thermal expansion to occur symmetrically without causing misalignment during temperature changes.
• Wear Ring Protection: Replaceable wear rings protect the casing from wear and allow easy restoration of original clearances without replacing the entire casing.
• Rigid Baseplate: Heavy fabricated steel baseplate with integral grouting holes ensures stable mounting and precise alignment in pump stations and industrial facilities.

Technical Specifications

Key Industries & Applications

• Power Plant Cooling Water Circulation: High-volume cooling for thermal power plants, nuclear power stations, and cogeneration facilities. Flows up to 20,000 m³/h ensure adequate cooling for multi-hundred-megawatt turbine condensers.
• Municipal Water Supply & Drainage: Raw water intake from rivers and reservoirs, treated water distribution pumping, and stormwater/flood control stations. The axially split casing allows rapid maintenance during peak demand periods.
• Industrial Process Cooling: Cooling water circulation for refineries, petrochemical plants, steel mills, and manufacturing facilities. Handles continuous 24/7 operation with high reliability and low vibration.
• Large-Scale HVAC & District Energy: Chilled and hot water circulation for district heating/cooling networks, large commercial complexes, airports, and data centers. VFD control enables energy savings of 30-50%.
• Agriculture & Irrigation: Large-scale irrigation pumping for agricultural districts, golf courses, and land reclamation projects. High flow rates at moderate heads provide efficient water distribution over large areas.
• Water Treatment & Fire Protection: Raw water feed for treatment plants, backwash supply for filtration systems, and high-volume fire protection pumps for industrial facilities and airports.

Cross-Sectional Structure & Component Key

How to Select the Right CW Model

Selecting the correct CW series horizontal double suction pump requires matching four core parameters to your system requirements:

01. Required Flow Rate (Q): Determine the maximum and minimum flow your system demands. The CW series covers 50 to 20,000 m³/h. For flows above 500 m³/h, double suction split case pumps are generally more efficient and cost-effective than end suction pumps.
02. Total Dynamic Head (TDH): Calculate total head including static elevation, friction loss in piping and heat exchangers, and required terminal pressure. The CW series delivers heads up to 200m.
03. Fluid Properties & Material: Clean freshwater and industrial cooling = Cast Iron/Cast Steel. Corrosive media = SS304/SS316 or Bronze. Highly corrosive = Duplex 2205. For fluids above 120°C, specify high-temperature mechanical seals with cooling jacket.
04. Installation & Maintenance Requirements: Choose the axially split case design for high-flow applications requiring frequent maintenance access. The split casing allows complete internal inspection without removing the pump from the pipeline.

Quality Control & Testing

• 100% Hydrostatic Pressure Testing: All pump casings are hydrostatically tested at 1.5x maximum working pressure for a minimum of 10 minutes, with zero leakage acceptable.
• Performance Verification Testing: Each pump is performance-tested on our in-house test bench (up to 2,500 kW capacity) to verify flow rate, head, efficiency, and NPSHr against the published performance curve.
• Material Traceability: All wetted components come with material test reports (MTR 3.1) verifying chemical composition and mechanical properties.
• Dynamic Shaft Balancing: All rotating assemblies are dynamically balanced to ISO 1940 G6.3 grade to minimize vibration and extend bearing and seal life.
• Shaft Alignment Verification: Each pump-motor assembly is laser-aligned on the baseplate before shipment to ensure precise coupling alignment.

Frequently Asked Questions

Q1: What is the advantage of double suction over single suction end suction pumps for high-flow service?
A1: Double suction impellers cancel axial hydraulic thrust, allowing operation at much higher flow rates (up to 20,000 m³/h) with minimal vibration and extended bearing life. The axially split casing allows complete internal inspection without disconnecting piping, reducing maintenance downtime by up to 70%.

Q2: What materials are available for the pump casing and impeller?
A2: Standard construction uses cast iron or cast steel for freshwater and industrial cooling service. For corrosive media, we offer SS304/SS316 stainless steel, Nickel-Aluminum Bronze, Duplex Stainless Steel (2205), and advanced SEBF epoxy powder coatings. All materials come with MTR 3.1 test reports.

Q3: Can these double suction pumps be integrated with existing PLC or VFD systems?
A3: Yes. Our pumps are fully compatible with mainstream VFD and PLC smart control systems, enabling precise flow management, pressure regulation, and energy-saving automation. Standard Modbus and Profibus protocol support enables seamless integration into SCADA networks.

Q4: What is the difference between horizontal and vertical split case pumps?
A4: Horizontal split case pumps are mounted horizontally with a baseplate, offering easier maintenance access and higher flow capacity (up to 20,000 m³/h). Vertical split case pumps have a smaller footprint and are ideal for pump stations with limited floor space or retrofit projects.

Q5: What is the lead time for CW series double suction pumps?
A5: Standard cast iron configurations usually take 15-25 working days. Custom material specifications (stainless steel, bronze, or duplex) take 30-45 days. Large pumps (above DN500) may require 45-60 working days. Third-party inspection adds 5-10 working days.

Q6: Can you provide custom dimensions for retrofit projects?
A6: Yes. FILIPUSI specializes in custom-engineered pumps for retrofit and modernization projects. We can manufacture pumps with custom flange-to-flange dimensions, shaft heights, and baseplate mounting patterns to match existing pump room boundaries and legacy flanges.

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