LEWA Metering Pump Applications: Where ecoflow and ecodos Fit Best

A LEWA metering pump is usually found where a small solenoid dosing pump would not survive: refinery injection points, offshore chemical skids, chemical reactors and hygienic food lines. The German manufacturer builds process-grade diaphragm pumps, and the real question for most buyers is not whether the pump is good, but whether their duty actually needs one.

This guide walks through the duties where a LEWA metering pump earns its price, where it is overkill, and what information to collect before you request a quote.

Two product lines to know first

Most enquiries end up with one of two series on the LEWA brand page.

Figure 1: LEWA ecodos mechanical diaphragm pump. Image source: LEWA official website

• LEWA ecoflow is the hydraulically actuated diaphragm metering pump. LEWA states it follows API 675, comes with the patented DPS diaphragm protection system, a sandwich diaphragm with monitoring, and an adjustable pressure relief valve in the hydraulic section.
• LEWA ecodos is the mechanically actuated diaphragm pump for low-pressure work. It is oil-free on the process side, quoted at ±1% flow adjustment accuracy, with a turndown of up to 1:50 using stroke length and speed.

If pressure is high or the fluid is dangerous, start with ecoflow. If pressure is low and the fluid must never see oil, start with ecodos.

High-pressure chemical injection

Corrosion inhibitor, methanol, demulsifier and scale inhibitor injection are classic jobs for a LEWA metering pump. Injection points sit against well or process pressure, and a stopped pump can mean hydrate plugs or corrosion damage. LEWA lists suction capability down to 0.1 bar absolute for ecoflow, and a spring pulls the diaphragm into a safe position when the pump is idle, which makes start-up gentler on the diaphragm.

Service life is the other selling point. LEWA says that with regular maintenance these pumps can run for 40 years or more. On a continuous plant, that matters more than the purchase price gap.

Toxic, flammable or expensive fluids

A diaphragm pump has no dynamic seal on the wetted side, so the working chamber is hermetically sealed. With a sandwich diaphragm and rupture monitoring, a diaphragm problem is flagged before the process fluid is contaminated. That is why plants dosing hydrofluoric acid, chlorine, catalysts or pharmaceutical intermediates often specify a LEWA metering pump even for modest flow rates.

For a wider view of pressure classes and pump types, see our high-pressure metering pump selection guide and the article on the API 675 standard for hydraulic diaphragm pumps.

Clean low-pressure dosing with ecodos

Not every duty needs a hydraulic diaphragm. In food, beverage and fine chemicals, many feeds run at low pressure but demand accurate flow and zero oil contact. LEWA offers ecodos in six output ratings, with wetted parts in 316/316L stainless steel, PVC, PVDF or PTFE.

Flow can be controlled through a frequency converter on the motor or an automatic stroke actuator, which keeps DCS integration simple. LEWA also notes that a sanitary ecodos handles diatomaceous earth slurry during beer, wine and juice filtration, a good example of a low-pressure duty that is still demanding.

Multiple injection points and special temperatures

A single process unit often has several injection points. LEWA drive units can be combined, with identical or different outputs, to reduce pulsation or to run recipe dosing. One motor driving several pump heads saves space compared with a row of single pumps and keeps piping tidier.

Temperature is easy to forget on a data sheet. Pump heads can be fitted with heating or cooling jackets, so a LEWA metering pump can handle cold liquefied gases or hot melts. Wetted parts are available in Hastelloy and duplex steel as well as standard stainless steel. State the full temperature range up front so the right jacket and valve design are chosen.

What to prepare before asking for a quote

A LEWA metering pump is engineered to the duty, so vague data means slow quotes. Gather the following:

1. Fluid: name, concentration, temperature, viscosity, solids content and any tendency to crystallise or gas off.
2. Flow: normal, minimum and maximum, not just one figure.
3. Pressure: maximum discharge pressure at the injection point and the suction condition, flooded or lift.
4. Site: hazardous area classification, indoor or outdoor, ambient temperature range.
5. Control: manual, 4-20 mA, VFD or stroke actuator, and any required signals back to the control system.

With this list, the supplier can settle head material, diaphragm design and drive size in one pass instead of three rounds of email.

Common mistakes we see

Using a process pump for an easy job. Dosing ferric chloride or hypochlorite at a few bar in a municipal plant does not need a LEWA metering pump. It will work, but spares and capital cost will not pay back.

Quoting only discharge pressure. Suction conditions often decide the pump. A fluid close to its vapour pressure on a lift suction is harder than a high discharge pressure.

No spares on the shelf. Imported diaphragms and valve sets can take weeks. Keep a set of wear parts for every critical LEWA metering pump.

Conclusion

A LEWA metering pump fits best where pressure is high, operation is continuous and the fluid is hazardous or expensive, and ecoflow is the workhorse there. For clean, oil-free low-pressure dosing, ecodos is the better match. Ordinary water treatment dosing rarely needs process-grade hardware.

Collect fluid, flow range, pressure, site and control data first, then narrow down the series. If you want a second opinion on pump type or materials, contact our engineers and we will check the duty with you.

FAQ

How is a LEWA metering pump different from a solenoid dosing pump?

Solenoid pumps cover small, low-pressure water treatment dosing. LEWA builds motor-driven process diaphragm pumps with far higher pressure capability and duty ratings, at a different cost level.

Is every ecoflow a hydraulic diaphragm pump?

The standard ecoflow uses a hydraulically actuated diaphragm with DPS protection. LEWA also offers a packed plunger version of ecoflow for certain duties.

Can a LEWA metering pump be used in a hazardous area?

Yes. LEWA designs injection packages to standards such as ATEX. Specify the zone and gas group at the enquiry stage so the motor and accessories match.

What fluids suit the ecodos?

Ordinary chemicals and food-grade products at low pressure. Choose stainless steel, PVC, PVDF or PTFE wetted parts according to chemical compatibility.

How do I deal with long lead times on imported spares?

Run critical points with a duty and standby pump, keep a diaphragm and valve kit on site, and follow the service interval rather than waiting for a failure.