Grundfos Smart Digital DDA-C Compact Positive-Displacement Diaphragm Dosing Pumps

The Grundfos SMART Digital DDA‑C series is a line of compact, positive‑displacement diaphragm dosing pumps built for precision chemical injection. Designed to replace the previous DDA models, the ‑C suffix stands for Connectivity . These pumps are available across a broad range of flow rates and pressure ratings, with multiple wetted material configurations to handle aggressive chemicals, degassing liquids, and high‑viscosity fluids. All models operate on a universal power supply (100‑240 VAC, 50/60 Hz) and share a modular mechanical architecture for flexible installation.

Flow Rate, Pressure & Chemical Compatibility

The DDA‑C series spans a flow range from 0.0025 L/h up to 30 L/h (0.00066 GPH to 8 GPH), with maximum pressure ratings varying inversely with flow. Higher‑pressure variants reach 16 bar (232 PSI) at low flow rates, while high‑flow variants deliver up to 30 L/h at 4 bar (60 PSI) . Representative performance points across the line include:

Each flow/pressure variant can be ordered with multiple wetted materials to match specific chemicals. The available dosing head materials include Polypropylene (PP), Polyvinyl Chloride (PVC), Polyvinylidene Fluoride (PVDF), and 316 Stainless Steel . Gasket options include EPDM, FKM (Viton), and PTFE; valve balls are available in ceramic or stainless steel . For fluids that require exceptional chemical resistance, PVDF heads with PTFE gaskets and ceramic balls are offered . Additional configurations are made to order.

Control Variants, Actuation & Connectivity

The DDA‑C series is offered in two control variants:

• AR (Advanced Relay): Manual speed control via a potentiometer, pulse control in ml/pulse, and an output relay for alarm or timer functions .

• FCM (Flow Control Measurement): Adds integrated flow measurement, pressure monitoring, and the AutoFlowAdapt correction function that maintains target flow despite fluctuating back pressure .

All pumps are driven by a variable‑speed stepper motor operating at full stroke length, which ensures accurate priming and smooth, continuous flow even when handling high‑viscosity or off‑gassing fluids . An integrated auto‑deaeration function prevents air locks during standstill periods by automatically purging accumulated gas from the dosing head . SlowMode (two anti‑cavitation steps at 50% and 25% flow) further improves performance with high‑viscosity or degassing liquids .

All DDA‑C pumps feature embedded Modbus RTU and TCP communication, enabling direct integration into industrial control networks without external gateways. The pumps also include integrated Bluetooth for wireless setup, monitoring, and fleet management via the Grundfos GO app . Fieldbus modules (CIM/CIU) are available for Profibus DP, Profinet, and EtherNet/IP.

User Interface & Installation Flexibility

The pump is operated via a click‑wheel (turn‑and‑push knob) and a multi‑lingual, backlit graphical LCD with a four‑color “traffic light” status indicator . The control cube can be rotated to three positions (front, left, right) without tools , and the mounting plate offers three click‑stop orientations. A transparent cover protects the control interface while allowing at‑a‑glance status checks.

Accessories & Integration

The DDA‑C series is supported by a broad ecosystem of accessories:

• M12 5‑pole signal/power cable (e.g. Grundfos 96632922): 5 m length with a straight M12 plug, used for connection to external control devices such as process controllers, flow meters, start/stop contacts, and level sensors .

• Fieldbus modules (CIM/CIU 900): Enable Profibus DP, Profinet, or EtherNet/IP communication with the appropriate signal cables .

• Mounting kits, dosing heads, valve kits, and service parts: Available for all wetted materials .

All pumps have a turndown ratio up to 1:3000, allowing a single pump model to cover from trace dosing to near‑maximum flow . The enclosure is rated IP65 for use in harsh, washdown‑prone environments.

Applications

The DDA‑C series is used in water treatment, chemical processing, agriculture, and irrigation. Representative dosing tasks include:

• Oxidizer injection (e.g. sodium hypochlorite, chlorine dioxide, hydrogen peroxide) – with auto‑deaeration handling off‑gassing fluids

• Acid and alkali neutralization (pH control) – with PTFE diaphragms and ceramic balls for corrosion resistance

• Coagulant and flocculant metering in clarification and sludge treatment

• Antiscalant and biocide injection in reverse osmosis and cooling towers

• Fertigation and micronutrient injection in greenhouse and field irrigation

• Disinfection of drinking water, wastewater, and process water

• CIP chemical dosing in food, beverage, and pharmaceutical sanitation loops