Marine Double Suction Split Case Pumps

Why Choose Horizontal Split-Case Architecture?

Operational Principle & Structural Characteristics

The FILIPUSI marine 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 — a critical advantage for shipboard maintenance where dry-dock time is expensive.

• 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.
• Dual Seal Configuration: Mechanical seals or gland packing can be fitted on both sides of the impeller, with seal flush plans available for hazardous or high-temperature fluids.
• Rigid Baseplate: Heavy fabricated steel baseplate with integral grouting holes ensures stable mounting and precise alignment in vessel engine rooms.

Technical Specifications

Standard ratings for FILIPUSI marine horizontal double suction split case pump series:

Material Specifications

Primary Maritime Applications

FILIPUSI horizontal split case pumps deliver continuous high-volume capacity across primary shipboard fluid handling networks:

• Central Seawater Cooling Systems: Provides continuous, ultra-high-volume seawater supply to main engine heat exchangers and central coolers aboard large commercial vessels, cruise ships, and naval vessels. Flows up to 20,000 m³/h ensure adequate cooling for multi-megawatt propulsion systems, even in tropical waters with elevated seawater temperatures.
• Ballast Water Transfer & De-ballasting: Enables rapid high-flow fluid relocation across ballast tanks for fast vessel loading and stability control. The double-suction design handles the large volumes required for Post-Panamax and Ultra-Large Container Vessels (ULCVs), complying with IMO Ballast Water Management Convention requirements.
• On-Board Firefighting & Emergency Utilities: High-pressure configurations designed for standby deck fire protection and emergency bilge evacuation. SOLAS-type fire pump configurations available with appropriate pressure ratings, with classification society surveyor inspection arranged on request. Optional diesel engine drive for emergency power loss scenarios.
• Offshore Platform & FPSO Service: Seawater cooling, fire water, and utility service on offshore oil rigs, FPSO units, and offshore wind substations. Super Duplex 2507 construction withstands extreme salinity, structural vibration, and limited maintenance access. Explosion-proof motor options available for hazardous area zones (Zone 1/Zone 2).
• Dockside & Shipyard Pumping: High-volume water transfer for dry-dock dewatering, shipyard flooding systems, and port infrastructure. The horizontal split case design allows rapid maintenance during dry-dock periods, minimizing vessel off-hire time.
• Desalination Plant Intake & SWRO Feed: Large-capacity seawater intake for shipboard and land-based reverse osmosis desalination plants. Ni-Al Bronze and Duplex construction provide reliable service in raw seawater intake service with high suspended solids.

Marine Double Suction Pump for Large-Vessel Central Cooling

Large container ships, cruise vessels, tankers, and naval platforms circulate thousands of cubic metres of seawater per hour through central cooling systems — flows where a single-suction end suction pump becomes inefficient and suction conditions marginal. The marine double suction split case pump draws seawater into both sides of the impeller, halving NPSHr and balancing axial thrust for smooth, low-vibration running at very high continuous flow, making it the preferred central cooling pump on large tonnage.

Split Case Ballast Pump for High-Flow Ballast Transfer

Fast cargo turnaround depends on rapid ballasting and de-ballasting. The axially split double suction pump moves very large ballast flows at low-to-moderate head with high efficiency and generous internal passages that tolerate sediment and small solids stirred up from ballast tank bottoms. The split casing lets the rotor be lifted out for inspection or wear-ring replacement without disconnecting the large-diameter ballast piping, minimising dry-dock and alongside time.

Duplex Marine Split Case Pump for Seawater & Biofouling Resistance

For warm, biologically active, or polluted seawater — and for vessels trading in tropical or brackish waters — FILIPUSI supplies marine split case pumps in nickel-aluminium bronze, AISI 316/316L, and Duplex/Super Duplex stainless with silicon-carbide mechanical seals. These metallurgies resist chloride pitting, crevice corrosion, and macrofouling far better than cast iron or 304 stainless. Pumps are built to classification society requirements, with surveyor inspection and project-specific inspection certificates arranged on request.

Field Engineering Projects & Installation Showcase

FILIPUSI horizontal double suction split case pumps are widely deployed in major marine cooling installations, shipyard dock systems, and municipal high-flow pumping stations worldwide. Below are real-world project installations demonstrating our pumps' operational stability and robust construction:

Cross-Sectional Structure & Component Key

How to Select the Right Marine Double Suction Pump Model

Selecting the correct marine horizontal double suction split case pump requires matching five core parameters to your vessel system requirements:

01. Required Flow Rate (Q): Determine the maximum and minimum flow your system demands. The marine double suction 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. Select a pump operating at 80-110% of its Best Efficiency Point (BEP).
02. Total Dynamic Head (TDH): Calculate total head including static elevation, friction loss in piping and heat exchangers, and required terminal pressure. The double suction series delivers heads up to 200m. For seawater cooling, account for increased friction due to higher seawater density (1.025 g/cm³).
03. Fluid Properties & Material: Raw seawater cooling and ballast service = Nickel-Aluminum Bronze (C95800). Ballast water treatment and corrosive service = Duplex 2205 or Super Duplex 2507. Freshwater HVAC loops = Cast Steel or Ductile Iron. For fluids above 120°C, specify high-temperature mechanical seals with cooling jacket.
04. Classification Society & Flag State: Specify your vessel's classification society (ABS, BV, CCS, DNV, GL, LR, NK, KR) and flag state at order time so we can arrange the correct classification society inspection documentation, material test reports (MTR), and third-party inspection certificates.
05. 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. If you need a drop-in replacement for an existing pump, send us your existing pump dimensions or GA drawing for custom flange-to-flange matching.

Quality Control & Testing Procedures

Every FILIPUSI marine horizontal double suction split case pump undergoes rigorous quality control and testing before shipment:

• 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. Full traceability from casting to finished pump.
• 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.
• Third-Party Inspection: Classification society surveyor inspection (ABS, BV, CCS, DNV, etc.) available upon request, with full documentation package.

Maintenance & Service Guide

Proper maintenance ensures maximum service life and reliable operation. Recommended maintenance intervals for normal seawater cooling service:

Marine Pump Engineering FAQ

Q1: How does FILIPUSI guarantee long service life against aggressive seawater corrosion?
A1: We utilize specialized Bronze alloys (C95800 Nickel-Aluminum Bronze) and Duplex Stainless Steel (2205/2507) specifically cast for raw seawater exposure to eliminate galvanic pitting and velocity erosion. All wetted components come with MTR 3.1 material test reports, and every casing undergoes 100% hydrostatic pressure testing at 1.5x MAWP.

Q2: Can these horizontal double suction pumps be integrated with smart VFD controllers?
A2: Yes. All our units are fully VFD/PLC-compatible, allowing automated speed adjustments to lower power consumption during low-demand cooling cycles and support vessel EEXI/CII energy-efficiency targets. VFD control can reduce energy consumption by 30-50% compared to fixed-speed operation, with payback typically within 18-24 months.

Q3: What is the advantage of double suction over single suction end suction pumps for high-flow marine service?
A3: 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%. For flows above 500 m³/h, double suction pumps are generally more efficient and cost-effective than end suction pumps.

Q4: Are marine class certificates available for double suction split case pumps?
A4: Yes, we build to all major classification society requirements and arrange surveyor inspection with inspection certificates on a per-order basis, including ABS, BV, CCS, DNV, GL, LR, NK, and KR. We arrange the classification society inspection documentation, material test reports (MTR), hydrostatic test reports, and classification society surveyor inspection arranged on request, together with material test reports (MTR / EN 10204 3.1) and hydrostatic/performance test reports as required by the vessel's flag state and classification society.

Q5: Can you provide custom dimensions for vessel retrofitting projects?
A5: Yes. FILIPUSI specializes in custom-engineered marine pumps for vessel retrofitting and fleet modernization. We can manufacture pumps with custom flange-to-flange dimensions, shaft heights, and baseplate mounting patterns to match existing engine room boundaries and legacy flanges, enabling drop-in replacement of aging equipment without pipe modification.

Q6: What is the typical lead time for marine double suction split case pumps?
A6: Standard configuration pumps with cast steel or ductile iron construction typically have a lead time of 25-40 working days. Pumps with Bronze or Duplex stainless steel construction require 40-60 working days due to longer casting and machining times. Large pumps (above DN500) may require 60-90 working days. Pumps requiring classification society third-party inspection add 5-10 working days.

Q7: What is the maximum flow rate and head for the double suction series?
A7: The standard range covers flows from 50 to 20,000 m³/h and heads from 10 to 200 meters. For applications requiring higher heads, we can provide multi-stage configurations or recommend our VS vertical multistage pump series. For flows exceeding 20,000 m³/h, contact our engineering team for custom large-capacity pump designs.

Q8: Do you provide spare parts and after-sales technical support?
A8: Yes. FILIPUSI provides comprehensive after-sales support for all marine double suction pump models. We maintain an inventory of OEM spare parts including mechanical seal cartridges, bearing sets, impellers, wear rings, shaft sleeves, O-rings, and gaskets. Spare part kits can be shipped within 5-10 working days. Our engineering team provides remote technical support via email, WhatsApp, and video call.

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