Chemical Metering Pumps (Precision Flow Control)
When your analyzer or PLC demands accuracy, metering pumps deliver steady, measurable flow across wide turndown. We build solenoid metering, motor‑driven/mechanical diaphragm, hydraulic diaphragm, and peristaltic systems from LMI (including KML/KBL peristaltic), Walchem, Neptune, Emec, and Grundfos—integrated with flow verification and safety hardware.
Match Metering Technology to Signal, Fluid & Pressure
| Requirement | Best Metering Type | Recommended Brands | Notes |
|---|---|---|---|
| High turndown, tight control from PLC/4–20 mA | Digital solenoid metering | LMI PD, Grundfos SMART Digital (DDA/DDE), Walchem EWN, Emec | Very high turndown; fast stroke‑rate response; ideal for pH/ORP loops |
| Higher pressure lines / long runs | Motor‑driven mechanical diaphragm | LMI TD/SD, Neptune 500, Grundfos DMX | Robust drives; handles back‑pressure; steady output |
| Very high pressure / critical containment | Hydraulic diaphragm (API‑675 style) | Neptune 600, Grundfos DMH | Hydraulic oil isolates diaphragm; relief & burst protection |
| Viscous, shear‑sensitive or polymer solutions | Peristaltic | LMI KML / LMI KBL | Low shear, constant flow; excellent for flocculants and slurries |
| Off‑gassing oxidants (NaOCl, H2O2) | Solenoid metering with degassing head | LMI PD, Grundfos DDA, Walchem EWN | Flooded suction, back‑pressure valve, vertical discharge orientation |
Recommended Metering Packages (Placeholders)
Tip Provide target flow, discharge pressure, control signal (pulse/4–20 mA), chemical, temperature, and required turndown. We’ll include curves, accessories and P&ID.
How We Engineer Metering Systems
- Accuracy & verification—calibration columns, stroke‑count verification, optional flow verification.
- Hydraulics—back‑pressure valves stabilize checks; relief valves protect lines and heads.
- Installation—flooded suction, short straight runs; injection quills to pipe centerline.
- Materials—PVDF/316SS/PTFE by SDS and temperature; FKM/EPDM/FFKM elastomers as needed.
- Controls—pulse pacing, 4–20 mA, batch, or PID with local/remote starts and alarms.
Common Metering Applications
- pH/ORP control (acid, caustic)
- Disinfection & dechlorination
- Coagulants & flocculants
- Scale & corrosion inhibitors
- Boiler & cooling chemistry
- RO antiscalant & bisulfite
- Food & beverage sanitation
- Metal finishing/plating additives
- Waste neutralization & polishing
- Polymer make‑down & feed
Hit Your Setpoint—Every Shift
Send chemical, flow/pressure target, control signal, turndown, and site sketch. We’ll quote a metering system with the right accessories and documentation.
Chemical Metering FAQs
How much turndown do I need?
Most treatment loops need 10–100:1. Digital solenoid units can reach very high turndown; motor‑driven units offer excellent accuracy where pressure is high.
What verifies actual metered flow?
Calibration columns, stroke counting, or inline flow verification. We add alarm interlocks if commanded vs. measured flow deviates.
Why is my metering pump losing prime?
Common causes: off‑gassing fluids, long/undersized suction, no back‑pressure, or worn checks. Fix with flooded suction, degassing heads, a back‑pressure valve, and short suction lines.