Hydraulic Diaphragm
| Identification | |
| Manufacturer | Grundfos |
| Series | DMX |
| Model / size | DMX 125-8 |
| Dosing type | Hydraulic Diaphragm |
| Pump class | Category C — Hydraulic diaphragm, high-pressure industrial dosing. Oil-actuated PTFE composite diaphragm. Accuracy ±1.0%. Best for: critical process dosing, oil & gas, API 675 applications. Limit: 125.0 L/h, 80.0 bar. Highest reliability class. |
| Spec code | DSG-121 |
| Dosing duty | |
| Min flow | 50 L/h |
| Max flow | 125 L/h |
| Max pressure | 80 bar |
| Dosing accuracy | 1 % |
| Stroke frequency | 72 spm |
| Suction lift | 4 m |
| Max viscosity | 3000 cP |
| Control & drive | |
| Control type | Analog 4-20mA + Pulse + Profibus |
| Stroke adjustment | Variable speed 0-100% |
| Power | 662 W |
| Supply voltage | 100-240 VAC (auto) / 24 VDC V |
| IP rating | IP55 |
| Materials & chemical | |
| Liquid end | SS316 |
| Diaphragm | PTFE composite |
| Valve / ball | SS316 |
| pH range | 0-14 (full range — HF, concentrated acids, caustic) |
| Chemical compatibility | Coagulants, polymers, lime milk, sludge conditioning |
| Application | |
| Service | Wastewater Treatment, Water Treatment |
| Key features | Grundfos DMX 125, 125 L/h at 80 bar, hydraulic diaphragm, high flow, 1% accuracy, Profibus, 2-head |
A complete, shareable page for a single pump. It plots the performance curve (head, efficiency and NPSHr against flow, with the best-efficiency point marked, or dosing flow against stroke), decodes the API 682 / ISO 21049 mechanical seal plan, and lists the full specification — duty and operating range, drive and motor, materials of construction, build and reliability, connections, weight and certifications. Pop-up panels give the type-specific preventive-maintenance schedule (daily to annual tasks with procedures) and a troubleshooting guide (symptoms, probable causes and recommended solutions).
Run a centrifugal pump near its BEP and keep dosing pumps in their recommended stroke band. Data is from the engineering reference database — confirm against the manufacturer's certified curve before procurement.
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