APV Pumps (SPX FLOW)
DW Series – Piston & Bi-Lobe Rotor Pumps
DW Series – Piston & Bi-Lobe Rotor Pumps
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Product Type: Positive Displacement Pumps
Description:
The APV DW Series of positive displacement pumps is designed to deliver high volumetric efficiency while minimizing internal clearances — reducing both operating costs and energy consumption. Engineered for ultra-hygienic performance, DW pumps handle aggressive CIP/SIP cycles, offer pulse-free operation for smooth flow, and ensure gentle handling of sensitive, high-viscosity products.
Key advantages include:
- Low NPSH requirements, helping to eliminate cavitation
- Quiet operation, even at high speeds
- Simple maintenance with easily accessible components
- Reliable performance across a wide range of sanitary applications
Features – APV DW Positive Displacement Pump Series
The APV DW Series includes 26 hygienic pump models, all 3-A certified and designed in accordance with EHEDG standards to meet the most demanding sanitary requirements. The series offers a wide capacity range — from 3 liters/100 revs to 1016 liters/100 revs — with maximum pressure handling up to 435 psi (30 bar). All product-wetted parts are manufactured from AISI 316L stainless steel, and all elastomers are fully compliant with FDA requirements.
Key Benefits
- High Volumetric Efficiency
The DW pumps are built on the principle of delivering more performance per unit cost. With minimized internal clearances, the pump achieves exceptional efficiency — enabling the use of a smaller pump size in many medium-viscosity applications. This results in lower capital investment and reduced energy consumption.
- Ultra-Hygienic & CIP-Ready
All models are CIP/SIP cleanable and engineered to withstand rapid temperature shifts, making them suitable for harsh and frequent cleaning cycles in hygienic environments such as dairy, food, beverage, and pharmaceutical processing.
- Pulse-Free Operation
DW pumps provide completely pulse-free flow, even when handling high-viscosity products. This ensures process stability and protects sensitive downstream equipment, including filling machines and valves, from pressure spikes and surges.
- Low NPSH Requirement
With enhanced suction capabilities, the DW pump series offers a significantly reduced NPSHr, minimizing the risk of cavitation. Combined with its pulse-free operation, this makes it an excellent choice for applications such as ultrafiltration.
- Gentle Product Handling
Engineered for delicate processing, the DW’s circumferential piston and twin-lobe rotor options ensure maximum product integrity across a range of viscosities. These rotors can also handle challenging inclusions such as cheese curds, whey, soft fruit, and minced meat, without requiring custom rotor adaptations.
- Easy Maintenance
Designed for serviceability, the pump features front-loaded mechanical seals for quick access and minimal downtime. All shaft seal O-rings are standardized, and rotor timing is straightforward — simplifying routine maintenance and seal replacement.
- Low Noise Levels
A unique rotor geometry drastically reduces hydraulic noise, while helical gears contribute to smoother, quieter gearbox operation — creating a more comfortable working environment on the production floor.
Theory of Operation – APV DW Series
The APV DW Series pumps are positive displacement, low-slip units engineered for consistent flow and gentle handling of a wide range of fluids. Constructed from stainless steel, DW pumps are built with oversized shafts to deliver enhanced strength and rigidity, minimizing deflection under load. The shafts are supported by a robust cast iron bearing frame (with an optional stainless steel version), and feature double-tapered roller bearings to ensure long-term durability and smooth operation under demanding conditions.
Operating Principle
During operation, as the rotors begin to rotate, they create expanding cavities at the inlet. This draws fluid into the pumping chamber. As the rotors continue to turn and intermesh, the cavities collapse, and the liquid is gently displaced toward the outlet, resulting in pulse-free, consistent flow. This positive displacement mechanism ensures minimal shear, preserving the integrity of sensitive and viscous products.
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Blue-shaded areas represent product-filled zones in diagrams
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Empty cavities indicate suction phases in the pumping cycle
Key Mechanical Components
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Profiled Front Cover Gasket – Ensures reliable sealing and hygienic cleanability
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Front Cover – Protects internal components and allows for easy access
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Front Bearing – Supports the main shaft for smooth rotation
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Rear Bearing – Provides stability and alignment of the rotor assembly
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Main Shaft – Transmits torque to the rotor
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Auxiliary Shaft – Synchronizes rotor movement
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Helical Gears – Maintain precise rotor timing and reduce noise
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Clamp Ring – Secures front cover and components
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Pump Feet – Provide structural stability during installation
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Rotor Case – Houses the rotor assembly and defines the pumping chamber
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Rotor Nut – Locks the rotor in place
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Rotor – Main rotating element that displaces fluid
This design enables the DW pump to handle a wide range of product viscosities with excellent volumetric efficiency, low noise, and hygienic operation — making it ideal for food, dairy, beverage, and pharmaceutical applications.