Grundfos DME Digital Dosing Pump
Overview
Grundfos DME is a digital diaphragm dosing pump built around a microprocessor-controlled, variable-speed stepper motor that stays in direct mechanical contact with the diaphragm throughout the entire suction and discharge stroke. This continuous control – rather than the simple on/off solenoid stroke used in conventional dosing pumps – is what gives the Grundfos DME its defining characteristic: a turndown ratio of up to 1:800 with virtually unchanged dosing accuracy across the full capacity range. Covering outputs from 60 l/h up to 940 l/h depending on model variant, the pump is engineered for the precise, low-pulsation injection of disinfection, coagulation, pH-correction and other water-treatment chemicals into process lines where over- or under-dosing carries a direct cost or compliance risk.
As the official authorized partner and exclusive regional representative for Grundfos, Seven Star LLC proudly supplies the Grundfos DME digital dosing pump to municipal water authorities, desalination plants, industrial utilities and district cooling operators across the Sultanate of Oman and the wider GCC. Every unit shipped from our Muscat-area warehouse is backed by genuine Grundfos spare parts availability, manufacturer warranty and local commissioning support, so plant engineers in Muscat, Sohar and Salalah get factory-grade dosing performance without the lead times and uncertainty of grey-market imports.
Operating Principle
The dosing capacity of the Grundfos DME is set by automatic adjustment of motor speed during the discharge stroke, while the suction stroke runs at a separately configurable fixed speed – selectable at 100%, 75%, 50% or 25% of maximum. This decoupling of suction and discharge dynamics allows the pump to prime reliably and displace even outgassing or high-viscosity dosing media without air-locking, while the discharge side maintains a smooth, closely regulated flow rate rather than the sharp pressure spike typical of fixed-stroke diaphragm pumps. An integrated anti-cavitation function further slows the suction stroke automatically whenever difficult liquids or long suction lines threaten to starve the pump head, protecting the PTFE-coated diaphragm and check valves from dry-running damage.
Because dosing rate is derived from direct stepper-motor position control rather than stroke-length adjustment or bleed valves, the practical consequence for the operator is repeatable, linear dosing that holds its calibration as backpressure and viscosity vary through a shift or a season. The pump accepts manual dosing setpoints in ml/h, l/h or USgal/h, external 4–20 mA (or reverse-acting 20–4 mA) analogue control, pulse control from a flow meter or external controller, and both timer-based and pulse-based batch dosing – giving plant control systems a single dosing element that can be integrated however the process demands, including native PROFIBUS DP fieldbus communication for full SCADA visibility.
Engineering Design of the Grundfos DME
The Grundfos DME pump head and wetted assembly – pump head body, PTFE-coated diaphragm, ball check valves and manual bleed valve – are available in polypropylene, PVDF or 316 stainless steel, allowing the correct chemical compatibility to be matched to sodium hypochlorite, ferric chloride, caustic soda, acids or other aggressive dosing media without substituting the drive unit. The motor and control electronics are housed in an IP65-rated glass-fibre-reinforced plastic enclosure, giving the pump full protection against washdown, dust and the humid coastal conditions common to GCC water-treatment facilities.
Operator interaction runs through a logical control panel with one-touch buttons and a backlit, multi-language LCD display available in 14 languages, so capacity, calibration and alarm settings are configured directly at the pump without external software. A built-in on-site calibration function lets commissioning engineers calibrate the displayed dosing rate against the actual installed piping and backpressure in a single guided step. The unit also provides low-level and empty-tank signal inputs, an alarm relay output, overload protection, and onboard counters for pump strokes, operating hours and power cycles – giving maintenance teams the diagnostic data needed to schedule diaphragm and valve service proactively rather than reactively.
Key Features
The Grundfos DME digital dosing pump combines the following capabilities in a single compact unit:
- Dosing capacity range from 60 l/h to 940 l/h across the DME model range, covering small trim-dosing duties through to large plant injection points.
- Turndown ratio of 1:800 with consistent accuracy, eliminating the need to change pump size as process demand fluctuates.
- Stepper-motor controlled discharge stroke with independently adjustable suction speed (100/75/50/25%) for reliable priming of difficult liquids.
- Wetted parts available in polypropylene, PVDF or 316 stainless steel to match aggressive dosing chemicals.
- Manual, 4–20 mA analogue, pulse, timer-batch and pulse-batch control modes for direct integration with PLC and SCADA systems.
- Built-in PROFIBUS DP fieldbus communication module for remote monitoring and setpoint control.
- IP65-rated enclosure with backlit multi-language display and one-touch calibration for fast, tool-free commissioning.
- Integrated low-level/empty-tank alarm input, alarm relay output and stroke/hour counters for predictive maintenance.
Industrial Applications
The Grundfos DME is specified wherever a facility needs to inject a precise, repeatable volume of liquid chemical into a process stream: disinfection dosing (sodium hypochlorite, chlorine dioxide) at municipal and industrial water treatment plants, coagulant and flocculant dosing ahead of clarifiers and filters, pH correction with acid or caustic soda in RO desalination and boiler feedwater trains, and scale-inhibitor or biocide injection in cooling towers and district cooling plants. Its wide turndown and fieldbus connectivity also make it a common choice for pharmaceutical and food-processing utilities where dosing accuracy is tied directly to product quality and regulatory compliance.
As the officially authorized partner for Grundfos, Seven Star LLC distributes the Grundfos DME to water treatment contractors, EPC firms and utility operators throughout Oman and the GCC, including the industrial and free zones of Sohar and Salalah, the desalination corridor along the Omani coast, and the hospitality and healthcare sectors in and around Muscat that depend on continuously dosed potable and process water systems. Regional stock holding means replacement diaphragms, pump heads and control modules are available locally rather than on an import lead time, keeping dosing skids online through planned maintenance and unplanned failures alike.
Technical Specifications
The table below summarizes the core specifications of the Grundfos DME digital dosing pump range.
| Parameter | Specification |
|---|---|
| Model | Grundfos DME Digital Dosing Pump |
| Dosing capacity range | 60 – 940 l/h (model dependent) |
| Turndown ratio | 1:800 |
| Drive type | Microprocessor-controlled variable-speed stepper motor |
| Control modes | Manual, 4–20 mA / 20–4 mA analogue, pulse, timer-batch, pulse-batch |
| Fieldbus | PROFIBUS DP (built-in module) |
| Wetted materials | Polypropylene, PVDF, 316 stainless steel |
| Diaphragm | PTFE-coated |
| Enclosure rating | IP65 |
| Display | Backlit LCD, 14 selectable languages |
| Alarm & monitoring | Low-level/empty-tank input, alarm relay output, stroke/hour counters |
| Suction stroke speed | Adjustable: 100%, 75%, 50%, 25% of maximum |
Request a Quote for Grundfos DME Digital Dosing Pump
Seven Star LLC is ready to support your dosing project from specification through commissioning. Submit a formal RFQ for the Grundfos DME digital dosing pump to receive configuration guidance on wetted materials, capacity sizing and control interface, along with lead times from regional warehouse stock across Oman and the GCC. Technical datasheets, calibration guidance and installation drawings are available on request from our instrumentation division. As the authorized partner for Grundfos in Oman and the GCC, Seven Star LLC backs every DME pump supplied with genuine manufacturer warranty and locally stocked spare parts.
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