Doseuro Metering Pump Selection: How to Read the FPZ Catalog

Doseuro metering pump selection gets much easier if you read the catalog in a fixed order: return type, liquid end, flow and pressure, then material and control codes. Doseuro is now part of the Italian FPZ group, and you will find both a US edition (GPH and PSI) and European data sheets (L/h and bar) in circulation. This guide is for buyers and engineers who have the factory literature in hand and want to shortlist a model before asking for a quote.

What the catalog index tells you

For Doseuro metering pump selection, the index of the general catalog is basically a family tree:

Figure 1: Doseuro positive return (PDP) motor-driven metering pump. Image source: Doseuro official website (FPZ)

PDP series: AI positive return plunger pumps and SDI sandwich hydraulic diaphragm pumps
SR series: A plunger, D mechanical diaphragm, B&BR hydraulic diaphragm, SD sandwich hydraulic diaphragm and FM mechanical diaphragm
SDP series: S type solenoid pumps
H series polymer preparation plants, EM series mixers and accessories

The first split is the return mechanism. PDP pumps are positive return and the catalog says they comply with API 675 mechanical and performance requirements, with accuracy within ±1% over 10 to 100% of rated capacity. SR pumps use spring return, are simpler, and cover most water treatment and general chemical duties. If your project specification calls for API documentation, that alone narrows your Doseuro metering pump selection to the PDP pages. Background on the standard is in our API 675 hydraulic diaphragm pump guide.

Plunger or diaphragm in Doseuro metering pump selection

The liquid end is the second Doseuro metering pump selection decision. Each model page has a short "normally used when" list. Put them side by side and the differences are clear.

A type plunger pumps suit clean, non-abrasive liquids where drip-proof sealing is not essential and pressure is high. Flushing or leakage recovery is optional.

D and FM mechanical diaphragm pumps suit liquids with small amounts of suspended solids, toxic chemicals and leak-tight duty where high pressure is not needed. The FM has an all-plastic casing for acid environments and manual stroke adjustment only.

B&BR hydraulic diaphragm pumps combine a sealed diaphragm with plunger-like pressure capability; the BR version adds a built-in safety valve in the hydraulic circuit. SD and SDI use a sandwich diaphragm with rupture detection for duties where no leakage is accepted. For a deeper comparison, see Doseuro plunger vs hydraulic diaphragm.

Reading flow and pressure tables for Doseuro metering pump selection

The US catalog (FPZ USA 2020) lists capacity in GPH and pressure in PSI. The European data sheets use L/h and bar. Two conversions cover most cases: 1 GPH is about 3.785 L/h, and 1 bar is about 14.5 psi. Models prefixed AP are high-pressure versions; the AP A125N is rated to 3,335 PSI but delivers far less flow than the standard A125N.

Gear ratio columns and 50/60 Hz

The Model D sheet lists each head size with several reducer ratios, coded I, F, C and B. For the D050N-30, ratio I gives 35 strokes per minute and 5 L/h at 50 Hz, while ratio B gives 116 SPM and 17 L/h. On 60 Hz both stroke rate and flow rise. Size from the column that matches your supply; don't quote 60 Hz flow for a 50 Hz plant.

Metal vs plastic heads

Maximum pressure is often given in two columns. The D050N-30 is rated 14 bar with a metal head but 10 bar with a plastic head. If your Doseuro metering pump selection uses a PVC or PP head, read the plastic column. This is the line people miss most often.

Model and material codes that finish a Doseuro metering pump selection

The last page of the data sheet explains two code formats. A short code like D 100N 70 B 11 DV E reads as pump type, head size, diaphragm diameter, gear ratio, material, valve type and extras. The long code adds stroke control (1 manual, 2 4-20mA, 3 pneumatic, 8 PROFIBUS DP) and motor phase (0 no motor, 1 single phase, A three phase).

Standard wetted material codes include 11 (S.S.316L head with stainless balls), 12, 13 and 23 (PP, PVC and PVDF heads with Pyrex balls and PVDF seats) and 16 (PVC head with stainless balls). Diaphragms are PTFE coated and valve gaskets are FPM across these codes. Full Model D sizes are in our Doseuro Model D guide.

A six-step Doseuro metering pump selection routine

Putting it together, a typical Doseuro metering pump selection goes like this:

Liquid: solids, toxicity and leak tolerance decide plunger, mechanical diaphragm or hydraulic diaphragm.
Pressure: take maximum system pressure plus margin and check the correct metal or plastic column; go to AP versions if needed.
Flow: pick a gear ratio in the 50 Hz column so normal flow sits at roughly 30 to 80% stroke.
Materials: check chemical resistance, then map it to codes such as 11, 12, 13, 16 or 23.
Control: manual, 4-20mA actuator, pneumatic or fieldbus, plus motor voltage and whether explosion-proof or ATEX is required.
Accessories: safety relief valve, back pressure valve and pulsation dampener. The HSTPVC dampener is limited to 50 °C; use the stainless HSTX above that.

One Doseuro metering pump selection habit to avoid: oversizing "for margin" and then running below 20% stroke for years. Accuracy usually suffers at the bottom of the range, so it is often better to size for the normal duty and cover peaks with a second pump. For low flows without a motor, look at the Doseuro SDP solenoid pump.

Conclusion

Good Doseuro metering pump selection follows one sequence: choose return type and liquid end, find flow by gear ratio in the 50 Hz column, confirm pressure in the right material column, then lock material and control with the code. The catalog notes that data is for reference only, so send us your chemical, temperature, pressure and control needs and contact our engineers to verify each line. The full range is on our Doseuro brand page.

FAQ

Can I mix US and European catalogs for Doseuro metering pump selection?

Yes, but convert units first. The US edition uses GPH and PSI while European sheets use L/h and bar.

What does the AP prefix mean?

AP marks a high-pressure version. Pressure rating goes up sharply and flow is typically much lower than the standard size.

What do I need for stroke control code 2?

Code 2 is a 4-20mA automatic actuator. It needs a control signal from a PLC or controller; check the model manual for actuator power.

Why is the plastic head rated lower?

Plastic is weaker than stainless steel. The catalog lists metal and plastic pressures separately, so size PVC or PP heads from the plastic column.

Is the material list in the catalog the only option?

No. The catalog says other materials are available on request; confirm feasibility and lead time with the factory or with us before ordering.