Grundfos 99200700 DDA 7.5-16 FCM-PP/E/C Dosing Pump

Grundfos 99200700 DDA 7.5-16 FCM-PP/E/C-F Digital Chemical Dosing Pump

The Grundfos 99200700 (DDA 7.5-16 FCM-PP/E/C-F 31U2U2FX) is a microprocessor-controlled positive displacement diaphragm dosing pump engineered for demanding continuous-duty chemical injection. Operating via an internal variable-speed stepper motor with eccentric drive, the DDA FCM delivers ultra-smooth, continuous stroke discharge without pressure surges, achieving a 1:3000 turn-down ratio and dynamic flow adjustment down to 0.0025 l/h.

The integrated FlowControl Management (FCM) suite continuously monitors injection dynamics without external flow meters. By sampling diaphragm position against hydraulic pressure profiles inside the liquid end, the pump detects cavitation, overpressure, discharge pipe rupture, and air-entrainment bubbles in real-time. The PP/E/C configuration combines a Polypropylene head, pure EPDM elastomer seals, and industrial Ceramic valve balls, optimized for alkaline dosing, boiler chemical injection, scale inhibitors, and cooling water biocides.

Technical Details:

Key Features

1. Turn-Down Ratio of 1:3000: Precision stepper motor eliminates pulsation damping buffers in low-injection scenarios by maintaining constant stroke speed while regulating suction speed.
2. Integrated Auto-Deaeration: Software-governed air-purge valve cycles activate automatically when bubbles accumulate during standby or high-off-gassing chemical metering (e.g., sodium hypochlorite).
3. Modular Control Cube: 3-position click-and-twist operator cube allows the backlit graphical display and jog wheel to face forward, left, or right inside restricted marine chemical enclosures.
4. SlowMode Cavitation Prevention: Adjustable suction stroke speed profiles preserve volumetric injection accuracy when drawing high-viscosity antifoams or coagulants without cavitation.

Applications

• Marine Boiler Feedwater Conditioning: Precise injection of oxygen scavengers (DEHA, hydrazine), alkalinity builders, and amine condensates directly into low-to-medium pressure steam lines up to 16 bar.
• Reverse Osmosis (RO) Plants: Dosing of sodium metabisulfite for chlorine neutralization and acid-based scaling inhibitors prior to membrane banks.
• Engine Cooling Water Chemistry: Continuous metering of corrosion inhibitors (nitrite/borate or silicate blends) into main engine jacket water systems.
• Municipal & Industrial Water Treatment: Accurate disinfection injection using sodium hypochlorite, chlorine dioxide, and PAC coagulants.

Frequently Asked Questions

What distinguishes the DDA FCM model from the DDA AR or DDE versions?

The DDA FCM is Grundfos’s top-tier intelligent configuration. Unlike the DDE (basic manual) or DDA AR (analog/relay basic) models, the FCM features internal strain-gauge sensors that measure flow in real-time, detect micro-bubbles/airlocks, auto-correct for line pressure fluctuations up to 16 bar, and deliver analog output feedback of line pressure and flow.

Can the Grundfos 99200700 run on 115V 60Hz marine electrical grids?

Yes. The pump features an active PFC universal wide-range switch-mode power supply that accepts 1 x 100-240 V AC at both 50 Hz and 60 Hz without adjustments or internal jumper re-wiring.

What happens if the discharge line clogs or an injection quill scales up?

The integrated pressure monitoring system senses the overpressure spike above the programmed threshold (up to 16 bar). The pump stops the stepper drive immediately to protect the diaphragm, trips the potential-free Alarm Relay 1 to the engine control room, and illuminates the LED display red.

What is the purpose of the rotatable control cube?

In cramped chemical dosing cabinets or skids, space is at a premium. The modular DDA control cube can be removed via a one-click locking clip and turned 90° left or 90° right, allowing front-facing control even when the dosing head is piped parallel along a bulkhead.

How do I clear an “Air Lock / Cavitation” alarm on this unit?

If the pump senses air-locking, its auto-deaeration function initiates short, rapid suction/discharge strokes to vent gas pockets out through the deaeration bypass line. Verify that the suction tubing clamps are tight, clear any suction strainer blockages, and prime the head using the click wheel’s manual prime function.