How to Read a Metering Pump Model Number: Flow, Pressure, Materials

Plenty of buyers go looking for one master list of every metering pump model, hoping to look up a part number and be done. Even if that list existed it would not help much, because every manufacturer codes differently. The same "07" can mean pressure in one catalog and diaphragm size in another. Learning to split a code into its parts is far more useful than memorizing it.

The good news is that most metering pump model codes carry the same handful of facts: control type, flow, pressure, frame, liquid end material and power supply, sometimes with an adjustment option on the end. Two NEWDOSE coding systems make good worked examples.

What a Metering Pump Model Code Usually Contains

From years of checking codes for customers, we sort the segments into three groups:

• Whether the pump can do the job: flow, pressure and liquid end material. Get one of these wrong and the pump either won't fit the line or won't inject.
• How it is controlled: manual, pulse, 4–20 mA, RS485, or electric stroke adjustment.
• How it is powered: single phase 220 V or three phase 380 V, and whether a variable frequency or explosion-proof motor is needed.

Faced with an unfamiliar metering pump model, find those three groups first. Whatever letters remain are usually the frame or an option.

Solenoid Metering Pump Model Example: DFD-02-07-M-PPV-A

This example comes straight from the NEWDOSE selection manual. The six segments are:

1. DFD: control type. DFD is manual stroke frequency adjustment, DM takes an external current signal, DP an external pulse signal, and DC is adjusted over RS485.
2. 02: flow, 2 L/h.
3. 07: pressure, 7 bar.
4. M: frame. Options are M, HX, NX, GX, LM and X.
5. PPV: liquid end set. PP head, PTFE diaphragm and seats, ceramic balls, FKM seals.
6. A: power, 230 V 50/60 Hz with a 1.5 m cable. B is 115 V, C is a special requirement.

The manual also works one backwards. Maximum head 7 bar, 12 L/h, 230 V 50 Hz, a PVC head and current signal control gives DM-12-07-LM-PVT-A. Once you can take a code apart you can build one: fill in each segment from your duty.

Mechanical Metering Pump Model Example: NDWL-410-0.6-PVT-A-H

The mechanical diaphragm code adds an adjustment segment. First comes the series: NDJS, NDJL, NDWS, NDWL, ND1000, ND2000 or HND. Then 410 is flow in L/h, 0.6 is pressure in MPa, PVT is a PVC head, A is a standard three phase 380 V motor, and H is manual adjustment. Swap H for I and you get electric stroke length adjustment.

The power segment has more choices here. AVF is a variable frequency motor with an independent 380 V fan, AEX is an explosion-proof motor rated Exd Ⅱ BT4, and B is a standard 220 V motor.

The manual's own example is telling. The customer needs 370 L/h at 6 bar and the selected metering pump model is NDWL-410-0.6. The flow step is a little above the actual requirement, which leaves sensible margin.

Two Common Misreadings

Pressure units can change even within one brand

Put the two examples side by side. In the solenoid code, 07 means 7 bar. In the mechanical code, 0.6 means 0.6 MPa, which is 6 bar. Compare the raw numbers and the mechanical pump looks absurdly weak. When you read a metering pump model off a list or an old nameplate, confirm the pressure unit first.

The number is not always flow

Some brands put diaphragm size in the code. On the Iwaki EHN-BN11, for instance, 11 corresponds to a 10 mm diaphragm, not 11 L/h. Comparing numbers across brands without knowing the rules usually leads to the wrong answer.

Beyond the Metering Pump Model: Read the Data Table

A metering pump model code only tells you rated flow and pressure. For selection you still need the data table. Take the NDWS-18/1.6: 18 L/h, 16 bar, 2 mm stroke, 60 mm diaphragm, 118 SPM, 2.54 ml per stroke, 180 W motor.

Those figures tie together. 2.54 ml × 118 strokes × 60 minutes ÷ 1000 comes to roughly 18 L/h. Stroke rate and stroke volume together set the flow. A faster pump gives tighter pulses, while a bigger stroke volume hits the pipework harder, which is worth knowing when you size a pulsation damper.

Mechanical liquid end codes come in four types. PVT is a PVC head and PVDF a PVDF head, both with PTFE diaphragm and seats, ceramic balls and FKM seals. SST is an SS316 head with SS316 seats and balls. PTF is a PTFE head. The solenoid range adds PPV, a PP head.

How to Use Online Model Lists

Treat them as a way to check ranges: roughly what flow and pressure a series covers. Then go back to the manufacturer's selection manual and check every segment of the metering pump model. Never order straight from someone else's compiled list. One wrong letter and the material or power supply is completely off.

A better habit is building your own small list for the plant. For every metering pump model in service, record the nameplate code, the chemical and its concentration, the injection point and the line pressure, and note any head that was changed to a different material. When a pump fails and you need spares or a replacement, you look it up in seconds instead of climbing up to read a nameplate eaten away by chemical.

Conclusion

Reading a metering pump model is about taking it apart, not memorizing it. Find flow, pressure and material first, then control type and power, and finally check stroke rate, stroke length and stroke volume against the data table. Pressure units and the meaning of numbers vary between brands, and even between series from one brand, so check every segment against your duty before you order.

FAQ

The code doesn't show a pressure unit. How do I tell?

Check the manufacturer's coding notes. NEWDOSE uses bar for solenoid pumps and MPa for mechanical pumps, so even one brand differs. Don't guess.

Can I order a new pump from the old nameplate?

It is a good starting point, but recheck the chemical, flow and line pressure. If the duty has changed, the old metering pump model may no longer suit it.

Is the rated flow in the dosing pump model code what I will actually get?

Not exactly. Rated flow is measured under standard conditions. Viscosity and back pressure both affect real output, so calibrate on site after installation.

Why is there more than one metering pump model for the same duty?

Frame, stroke rate and stroke volume differ. The M, HX and NX solenoid frames overlap in range, for example, so control type and mounting dimensions decide it.

How does an explosion-proof pump show in the code?

On NEWDOSE mechanical pumps the power segment reads AEX for an explosion-proof motor rated Exd Ⅱ BT4. If the site needs explosion protection, get this segment right on the order.

Can't break a code down or not sure which step to pick? Send us your duty through our contact page.