Doseuro Model D Mechanical Diaphragm Pump: Sizes, Multi-Head and ATEX

Imported equipment lists often carry a code like D100N-70-B-11, and the questions we get are always the same: how much will it pump per hour, and is the pressure enough? Answering that for a Doseuro Model D means reading the code piece by piece. Model D is Doseuro's mechanical diaphragm metering pump. It's simple and easy to maintain, with one condition attached: it's meant for duties where pressure is not high.

Where the Doseuro Model D Fits

The data sheet opens with four conditions: the liquid contains small amounts of suspended solids, the liquid is hazardous, no leakage is allowed, and high pressure is not required. The more of these your duty ticks, the stronger the case for it.

Listed applications are coagulant, fertilizer, acid and polymer injection in fertigation, water treatment, paper, chemical, food and cooling tower service. In practice that means continuous low-to-medium pressure dosing in water treatment and general industry.

Reading the Doseuro Model D Code

Take D100N-70-B-11-DV-E:

1. D: pump type, mechanical diaphragm.
2. 100N: pump size, tied to stroke length.
3. 70: diaphragm diameter code.
4. B: reducer ratio, which sets strokes per minute.
5. 11: wetted material code.
6. The rest covers valve type and additional information.

On a Doseuro Model D the reducer letter matters. D050N and D100N have four ratios, I, F, C and B, giving 35, 58, 96 and 116 strokes per minute at 50 Hz. On the same pump head, the highest ratio delivers more than three times the flow of the lowest.

Flow and Pressure Across the Five Sizes

All figures below are at 50 Hz. Flow is somewhat higher at 60 Hz.

• D050N: D050N-30 covers about 5–17 L/h, up to 14 bar with a metal head and 10 bar with a plastic head. D050N-50 covers about 14–49 L/h at 10 bar.
• D100N: from 53–176 L/h on the D100N-70 to 132–438 L/h on the D100N-120, with pressure falling from 5 bar to 1.5 bar.
• D101N: D101N-70 reaches 8 bar, D101N-120 is 3 bar.
• D121N: D121N-120 covers about 332–570 L/h at 3 bar.
• D122N: metal and plastic versions. D122N-120 is 6 bar, -140 and -160 are 3 bar. Maximum flow is about 1330 L/h in metal and about 1400 L/h in plastic.

See the pattern? Bigger diaphragm, more flow, less pressure. It's the point we raise most often when going through Doseuro Model D figures with customers. A D100N-105 moves 360 L/h, but only at 1.5 bar, which won't get chemical into a pressurized main.

How We Size a Doseuro Model D

We work in three steps. Convert the maximum dose to liters per hour and add margin. Get the real pressure at the injection point and strike out every model that can't reach it. Only then choose a reducer ratio from what's left, so the normal flow sits in a middle setting rather than at the top.

A common example: antiscalant for a cooling tower, a few tens of liters per hour, into a return line at low pressure. Both D050N-50 and D100N-70 cover it. The first has more pressure margin, the second a higher flow ceiling, so let actual consumption decide. If the same flow has to go into a line at clearly higher pressure, the Doseuro Model D is the wrong tool and a hydraulic diaphragm pump makes more sense.

Installation matters too. When the injection point has almost no pressure, fit a back pressure valve on the discharge, otherwise liquid siphons through and flow swings. A relief valve protects the pump if someone closes a valve by mistake. On long lines, a pulsation dampener steadies the gauge a lot.

Wetted Material Codes

The Doseuro Model D has five standard material codes. 11 is all 316L stainless. 12 is a PP head, 13 a PVC head, 16 a PVC head with 316L balls, and 23 a PVDF head. All use a PTFE-coated diaphragm. Plastic heads use Pyrex glass balls, PVDF seats and FPM gaskets. Other materials can be made to order.

The usual rule applies: check chemical name, concentration and temperature together. With chlorine-bearing chemicals, don't assume stainless is the safe pick. Many customers just say "acid" or "caustic" without a concentration, and nobody can choose materials from that.

Simplex, Multi-Head and ATEX Motors

The Doseuro Model D comes in simplex and multi-head versions. A multi-head unit runs several pump heads from one drive, which helps when several chemicals go in near the same point or space is tight. Confirm the possible head combinations for your model with the factory.

Motors are 4-pole, UNEL-MEC compliant, 0.18–0.75 kW. Standard three-phase voltage is 220–240V(Δ)/380–415V(Y) 50Hz, and the standard single-phase supply is 230V 50Hz. For hazardous areas, an ATEX motor can be fitted, and voltage, frequency and higher insulation classes can also be specified.

Stroke Control and Construction

Stroke can be adjusted with the pump stopped or running, by hand or through an automatic actuator driven by 4-20mA, fieldbus or air. In the order code, stroke adjustment 1 is manual, 2 is 4-20mA, 3 is pneumatic and 8 is PROFIBUS DP.

The drive is a worm gear reducer on bearings, fully oil-bath lubricated, with a cataphoresis-painted gearbox. Standard connections are BSPP male from ½" to 1½", with flanges and other connections on request. A flushing pump head is available, and valves come in single ball or double ball.

Common Selection Mistakes

1. Choosing a Doseuro Model D by maximum flow without checking pressure. Large diaphragm sizes have low pressure ratings.
2. Treating metal and plastic heads as equal. D050N-30 is 14 bar in metal but 10 bar in plastic.
3. Forgetting that Model D is a low-to-medium pressure pump in the first place. High injection pressure means looking at hydraulic diaphragm or plunger pumps.

Conclusion

To read a Doseuro Model D, break the code into size, diaphragm diameter, reducer ratio and material code, and the flow and pressure fall into place. The range runs from a few liters to well over a thousand liters per hour, but pressure drops sharply as the diaphragm grows. For low-to-medium pressure duty with hazardous liquids or a no-leak requirement, it's a sound choice. Add an ATEX motor for hazardous areas, and a 4-20mA or fieldbus actuator for automatic control.

FAQ

How much does a D100N-70 pump per hour?

At 50 Hz, the four reducer ratios give about 53–176 L/h, with 5 bar maximum.

Can a Doseuro Model D take a PLC signal for flow control?

Yes. Choose an automatic actuator driven by 4-20mA, fieldbus or air. The order code has matching options.

Plastic or stainless head?

Start from the chemical. Corrosive chemicals usually call for PP, PVC or PVDF. On some models a metal head carries a higher pressure rating, as on the D050N-30.

Can a multi-head version dose two chemicals?

A multi-head unit is one drive with several heads, often used for different chemicals. Confirm the head combination with the factory.

Can it go in a hazardous area?

An ATEX motor can be fitted. State the hazardous area requirements on the order so the motor is matched.

If you want to compare the Doseuro Model D with a similar Chinese-made mechanical diaphragm pump, send the model and duty through our contact page.