Iwaki Metering Pump Price: How EHN Configuration Changes the Quote

There is no single Iwaki metering pump price, because the EHN solenoid pump is a family of configurations, not one product. The quote moves with five things written into the model code: the drive unit (BN or CN), the effective diaphragm diameter, the liquid-end material, the controller (standard R or advanced YN), and whether you need a special head such as auto-degassing NAE, high-compression 55 or high-pressure H. This guide is for buyers and plant engineers holding two or three EHN quotes that look nothing alike and trying to work out why.

Why the Iwaki metering pump price varies inside one series

A buyer asks for "an EHN" and gets two offers. One is a BN11 with a clear PVC head and the R controller. The other is a CN31 with a 316 stainless head and the YN controller. Both are EHN pumps, and comparing their Iwaki metering pump price line by line tells you nothing, because they are different machines. Before you compare numbers, decode each model string. Our walkthrough of the EHN model code position by position helps here.

Drive unit and diaphragm size set the flow class

The catalog lists two drive units: BN at an average 20 W and CN at 24 W. Effective diaphragm diameter comes in 10, 15, 20, 30 and 35 mm, shown as 11, 16, 21, 31 and 36 in the code. A bigger diaphragm moves more liquid per stroke, so the pump covers higher flow, and the Iwaki metering pump price climbs with each step.

A common mistake is buying the largest size "for safety." A solenoid pump running at a very low stroke rate delivers chemical in obvious pulses, and small doses get harder to hold steady. Size for your real maximum dose plus a sensible margin. You save money and usually get better control.

Liquid-end material: where most of the gap comes from

EHN offers several standard liquid ends:

• VC and VS: clear PVC heads. VC pairs alumina ceramic balls with FKM seats; VS uses balls equivalent to SUS316 with EPDM seats.
• PC, PS and PP: glass-fiber reinforced polypropylene (GFRPP) heads, with PP using PCTFE valve seats.
• FC: PVDF head.
• SH: SUS316 head with Hastelloy C276 equivalent balls.

Every version uses a PTFE-faced diaphragm with EPDM backing that never touches the liquid. Moving from PVC or GFRPP up to PVDF or stainless raises material and machining cost, and this choice usually explains the biggest part of the Iwaki metering pump price difference. Pick the material for your chemical, not to shave the Iwaki metering pump price. Sodium hypochlorite, sulfuric acid and caustic do not all want the same head, and stainless is not automatically the right answer.

R or YN controller: how it affects Iwaki metering pump price

The R controller lets you set stroke rate from 1 to 360 spm, and it supports EXT pulse multiplication and division plus a STOP input. Wire a level switch to STOP and the pump shuts off on low tank level. The YN controller adds analog input and digital input functions, and it can work with the optional FCM flow detector to alarm when the suction line has no flow.

Is YN worth the higher Iwaki metering pump price? If an operator sets a constant dose by hand, R is enough. If the pump must follow a 4–20 mA flow signal or a PLC for proportional dosing, buy YN. Saving on the controller and adding a signal converter later costs more in the end. Setup details are in our EHN digital controller settings guide.

Special heads NAE, 55 and H

Auto-degassing NAE

Sodium hypochlorite and hydrogen peroxide release gas. The gas collects in the pump chamber, the pump keeps clicking, and nothing comes out. NAE adds a built-in automatic air vent while keeping a manual vent, so it carries a higher Iwaki metering pump price than a standard head.

High-compression 55 and high-pressure H

The 55 type reduces dead volume in the chamber to raise the compression ratio, and Iwaki positions it for hypochlorite. The H type is for higher pressure points, such as dosing at a boiler feed pump discharge. Our comparison of auto-degassing and high-pressure EHN models covers the choice in more depth. Do not pay for a special head by default; a standard head with its vent valve handles many mild duties.

Accessories, sourcing and lead time

Injection check valves, foot valves, back pressure valves and the FCM flow detector are optional extras. One supplier bundles them, another quotes the bare pump. Line them up before you compare any Iwaki metering pump price.

Iwaki is a Japanese brand, and stock position and distribution channel also move the Iwaki metering pump price. Common models held locally ship and price differently from special builds that must be ordered. For the wider picture of imported versus Chinese-made pumps, read how imported metering pump prices compare.

One detail people miss: EHN housings are rated equivalent to IP66, yet the catalog states the pump must not be installed outdoors. An outdoor dosing point means budgeting for a protective enclosure.

What to send to get an accurate Iwaki dosing pump quote

To get a realistic Iwaki metering pump price, give the supplier:

1. Chemical name, concentration and temperature.
2. Maximum and normal dose rate.
3. Pressure at the injection point.
4. Control method: manual, level stop, or 4–20 mA proportional.
5. Accessories you need, such as an injection valve or back pressure valve.

Without these, a supplier quotes a default build. You only find out the head material is wrong or the pressure rating is short after installation. You can also compare other models on our solenoid metering pump page and see the full Iwaki product range.

Conclusion

Differences in Iwaki metering pump price come down to configuration. Drive unit and diaphragm size set the flow class, the liquid end sets chemical resistance, the controller decides whether the pump can follow a signal, and NAE, 55 or H solve gas locking and pressure problems. Fix the model code against your process first, then compare quotes for the same pump. Send us your flow, pressure and chemical and contact our engineers for a checked configuration and quote.

FAQ

Can you just tell me the Iwaki metering pump price for one EHN?

Not meaningfully. The EHN has many combinations, and a number given without chemical, flow and pressure data will not match the pump you actually need.

Is a PVC head cheaper than PVDF?

Usually yes, but only use PVC where the chemical and temperature allow it. A cheap head that cracks costs more than the saving.

Do I need NAE for every hypochlorite line?

No. NAE or 55 is worth it when the liquid is warm, the lines are long or the pump keeps losing prime. Mild duties can start with a standard head and its vent valve.

My quote has no back pressure valve. Should I add one?

If injection pressure is very low or the discharge line runs downhill, the pump can siphon and overdose. In that case add one and ask for it as a separate line item.

Can an EHN replace my old Iwaki EH pump directly?

In most cases, yes, but check mounting dimensions, tubing connections and control signals. Send the old nameplate and we will confirm.