Split-case Centrifugal Pump

A split-case centrifugal pump is a powerful pump characterized by a casing that can be split into two separate chambers, typically along a horizontal plane. This unique design allows for straightforward access to internal parts, making the pump easier to inspect and maintain than many alternatives.  

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These pumps are extensively used in water and wastewater treatment plants, where they transfer large volumes of clean or lightly contaminated water at moderate pressures. Their rugged construction and efficiency at high flow rates make them a preferred solution for municipal and industrial water distribution, clearwell transfer, and booster station applications.

• Raw water intake (from rivers, lakes, or wells to treatment facilities)
• Clearwell transfer (moving treated water to storage or distribution)
• Distribution booster stations (raising municipal system pressure)
• Recirculation loops within plant processes
• Backwash pumping for filters with low solids
• Not recommended for highly abrasive or high-solids wastewater

• Monitor and record pump/motor parameters (pressure, flow, vibration, temperature) at regular intervals.
• Inspect pump for leaks, noise, or vibration.
• Check and maintain lubrication on bearings.
• Keep the pump area clean and perform routine visual inspections.
• Grease/lubricate bearings per schedule and inspect or replace seals/packing as needed.
• Annually inspect internal wear by opening the split case.
• Always lockout/tagout power and isolate piping before servicing.
• Confirm proper alignment after major maintenance.
• Watch for cavitation (noise/vibration indicative of suction problems).

• Pump casing (split body): Encloses and directs flow; horizontal split for access/maintenance; pressure/material selection.
• Impeller: Rotating element imparting velocity; single/double suction; size/material to match duty and resist wear.
• Shaft and bearings: Transfers power from motor; supports impeller; type and lubrication ease affect reliability.
• Mechanical seals or packing: Prevents leakage at shaft exit; material and type selected for fluid compatibility.
• Baseplate/mount: Provides stable mounting; alignment and vibration damping features.
• Suction/discharge flanges: Inlet/outlet connections, correctly sized and rated for pressure.

• Flow rate: typically 500–50,000 GPM
• Total dynamic head (TDH): 30–250 ft
• Solid size handling: up to ¼ inch (mostly for clean to lightly contaminated water)
• Motor power: 15–2,000 hp (application dependent)
• Operating temperature: up to 85°C (185°F)
• NPSH required: typically less than 20 ft
• Compatible fluid: clean water, chlorinated water, mild chemicals

• Pump selection software: Manufacturer-specific (e.g., Flowserve Pump-FLO, KSB EasySelect, Xylem Xylect)
• Hydraulic calculation tools: AFT Fathom, Bentley WaterCAD, EPANET
• 3D modeling: Autodesk Plant 3D, SolidWorks
• CFD analysis (rare for standards): ANSYS Fluent

• 22 14 29 (Sump Pumps)
• 43 21 23 (Centrifugal Pumps)
• 43 25 13 (Water Process Pumps)
• 43 25 23 (Wastewater Process Pumps)

• ITT Goulds – 3655/3755, 3409 Series
• KSB – ETA/ETA-N Series
• Sulzer – SMD Split-Case Pump

• End-Suction Centrifugal Pump: Simpler and lower cost for small flows and moderate pressures; more compact but less efficient for high-flow/high-head.
• Vertical Turbine Pump: Best for deep well or sump installations; handles variable suction depths, but requires more complicated maintenance and installation.
• Axial Flow Pump: Optimal for very high-flow, low-pressure uses such as flood control; not suitable for moderate-to-high pressures or general plant distribution.