Features and benefits
DDI 222
Digital dosing pumps up to 150 l/h

The DDI series is firmly established on the dosing pump market with its combination of innovative drive technology and integrated microelectronics.
Users appreciate how they can simply enter the required dosing rate in litres per hour and let the DDI handle the rest.

Double-diaphragm system for optimum process reliability
Some processes must never be interrupted, not even in the event of a diaphragm rupture. The DDI is equipped with a double-diaphragm system. If the diaphragm fails, the DDI continues dosing thanks to the protective diaphragm.

Turndown ratio of 1:800
The DDI has a turndown ratio ten times better than that of conventional equipment. This allows us to create a complete pump series with just one motor, one gearing system, and two pump head sizes. You get the precision you want every time - and need only a minimum of spare parts and storage capacity.

Compact design
DDI pumps are smaller and quieter than conventional pumps in their class, which makes them easy to install anywhere. Order your DDI according to your wishes, with the control elements and display on the side or at the front.

Full stroke length every time
The DDI uses a full stroke length every time - a feature unique to Grundfos digital dosing pumps. Each stroke is carefully timed to bring you even concentrations in the system and optimum priming throughout the entire operating range.

Brushless DC motor
The brushless DC motor used in the DDI series ensures very smooth, continuous dosing while keeping energy consumption at a record low.

Anti-cavitation function
The SlowMode settings reduce the suction stroke systematically, so that difficult, viscous liquids are dosed with smooth precision. When set at 60 % of the maximum dosing rate, the DDI can dose liquids with a viscosity of up to 1000 mPas. When set at 40 %, the DDI can handle extremely viscous liquids up to 2600 mPas. You no longer need external dilution or treatment systems, but can dose chemicals directly and without waste.

Bus communication
The DDI is also available with a PROFIBUS DP interface.

Switch-mode power supply
DDI pumps can be used worldwide within the range of 110-240 VAC, 50/60 Hz.

FlowMonitor checks for malfunctions
The optional FlowMonitor detects any dosing errors on both the suction and discharge sides and immediately emits an error message if anything is wrong. It can also check for excess pressure: Just enter the maximum counterpressure allowed (in bar) and leave everything to the DDI. If the pressure is exceeded, the pump stops.

Diaphragm leakage detection
If the pump is supplied with diaphragm leakage detection, a differential pressure sensor sends an error signal as notification to replace the diaphragm.
When dosing crystallising media, the pump must be equipped with diaphragm leakage detection.
Examples of applications
• Industrial and municipal water treatment
• Industrial cleaning
• Polymer feed
• Paper production, paper finishing
• Optical technology and chip production
• Chemical industry
• Cleaning-In-Place (CIP) and disinfection
• Galvanic and surface treatment
• Air conditioning, water treatment in cooling towers
• Reverse-osmosis systems
• Semi-conductor industry.

Functional description
The DDI has a BLDC (brushless DC) motor and electronic power control.
The duration of each suction stroke is constant while the duration of each discharge stroke varies according to the set capacity.
This has many advantages:
• The full stroke length reduces gas build-up in the dosing head.
• Constant dosing ensures an optimum mixing ratio at the injection point.
• The significant reduction of pressure prevents mechanical stress on wearing parts such as diaphragm, hoses, pipes and connections.
• The installation is less affected by long suction and discharge lines.
• Easier dosing of highly viscous and volatile liquids