Sandwich hydraulic diaphragm dosing pumps – SD series
Doseuro SD pumps are sandwich hydraulic dosing pumps for dosing toxic, corrosive, hazardous liquids or liquids containing small amounts of solid particles, and where complete tightness and no leakage are required.
Doseuro SD dosing pumps are reliable and easy to maintain. They are equipped with a special layered diaphragm and a rupture detection system, which reduces the risk of leakage of the dosed liquid. Pumps in this series have adjustable stroke both during pump operation and during downtime. They are available in a standard version and a high-pressure ‘HP’ version.
In addition, pumps in this series have a built-in safety valve installed in the hydraulic circuit to protect the diaphragm from excessive pressure. Doseuro SD dosing pumps comply with the ATEX standard.
FAST FACTS
FEATURES AND BENEFITS
Doseuro SD pumps are sandwich hydraulic dosing pumps for dosing toxic, corrosive, hazardous liquids or liquids containing small amounts of solid particles, and where complete tightness and no leakage are required.
Doseuro SD dosing pumps are reliable and easy to maintain. They are equipped with a special layered diaphragm and a rupture detection system, which reduces the risk of leakage of the dosed liquid. Pumps in this series have adjustable stroke both during pump operation and during downtime. They are available in a standard version and a high-pressure ‘HP’ version.
In addition, pumps in this series have a built-in safety valve installed in the hydraulic circuit to protect the diaphragm from excessive pressure. Doseuro SD dosing pumps comply with the ATEX standard.
| Pump performance | Qmax = 1068 l/h | |
| Max. discharge pressure: | 14 bars 40 bars in the “HP” high-pressure version |
|
| Motor power: | 0.18, 0.25, 0.37, 0.55 or 0.75 kW, 1/3-phase, 1400 rpm | |
| Head material: | AISI 316L stainless steel, PP, PVC or PVDF | |
| Valve ball material: | AISI 316L stainless steel or “PYREX” glass | |
| Valve seat material: | AISI 316L stainless steel or PVDF | |
| Membrane material: | double PTFE membrane | |
| Valve O-ring Material: | FPM | |
| Connection types*: | ½”, ¾”, 1” male BSP *other connection types available on request |
|
| Example of using translate |
| Dosing of chemicals such as coagulants, fertilizers, acids, polymers, oxygen scavengers, amines and many others. Commonly used in the following applications:
|
Dosing pumps, SD series are spring-loaded plunger pumps designed for water treatment and industrial applications. They are reliable and easy to maintain, with the option of a flushing or leak recovery system. Doseuro SD dosing pumps are available in a standard version and a high-pressure ‘HP’ version.
SD sandwich diaphragm dosing pumps can be used wherever:
The most important feature of this pump series is the special laminated diaphragm (two PTFE diaphragms) and the reliable diaphragm rupture detection system. This significantly reduces the risk of leakage of the dosed liquid from the pump head due to the absence of hydraulic seals in direct contact with the pumped liquid. In the event of a membrane rupture, the special double membrane design prevents the dosed liquid from escaping or mixing with the hydraulic oil.
Pumps in this series have adjustable stroke both during pump operation and during downtime. Stroke adjustment can be performed manually or automatically using an automatic actuator driven by 4-20 mA; various BUS; or pneumatically.
Dosing pumps are positive displacement piston pumps with controlled volume. The reciprocating motion provides a sinusoidal flow rate, therefore the flow of the pumped product is not continuous, but pulsating. The flow rate or volume of the pump is controlled by changing the stroke of the piston/diaphragm. The reciprocating motion of the piston/diaphragm of the dosing pump determines the flow thanks to directional valves located at the inlet and outlet of the pump head. The liquid is pumped in the following phases:
Sucking phase
During the suction phase, the valve at the outlet closes (sealing the leak), and the valve at the suction opens. Fluid enters the pump head chamber. The theoretical volume is equal to the piston displacement.
Stamping phase
During the compression phase, the suction-side valve closes and the discharge-side valve opens. The liquid leaves the pump head and flows into the pipe.
| Plunger dosing pumps | Doseuro A series
The SR-A series dosing pumps are plunger metering pumps with spring preload designed for water treatment and industrial applications. They are reliable and easy to maintain, with the option of a flushing or leak recovery system. Tapflo A series dosing pumps are ideal for applications where:
Want to know more? Check out Doseuro A dosing pumps. |
![]() |
| High-pressure plunger dosing pumps | Doseuro A series ‘HP’
The SR-A series dosing pumps are plunger metering pumps with spring preload designed for water treatment and industrial applications. They are reliable and easy to maintain, with the option of a flushing or leak recovery system. Tapflo A series dosing pumps are ideal for applications where:
Want to know more? Check out Doseuro A ‘HP’ high-pressure dosing pumps. |
![]() |
| Mechanical diaphragm dosing pumps | Doseuro D series
The SR series diaphragm dosing pumps are metering pumps with a return spring designed for water treatment and industrial applications. They are designed for pumping liquids with a low solid content in applications that do not require high pressure. Tapflo D series dosing pumps are ideal for applications where:
Want to know more? Check out Doseuro D dosing pumps. |
![]() |
| Mechanical diaphragm dosing pumps | Doseuro FM series
The FM series dosing pumps are spring-loaded plunger pumps designed for water treatment and industrial applications. They are reliable and easy to maintain, with the option of a flushing or leak recovery system. Doseuro FM dosing pumps with a mechanical diaphragm are designed for pumping liquids with a low solid content. These devices are ideal for applications where:
Want to know more? Check out Doseuro FM dosing pumps.
|
![]() |
| Hydraulic diaphragm dosing pumps | Doseuro B/BR series
The B and BR series dosing pumps are hydraulic diaphragm dosing pumps designed for water treatment and industrial applications, for pumping liquids with low solid content in applications requiring high pressure. Tapflo B/BR series dosing pumps are ideal for applications where:
Want to know more? Check out Doseuro B/BR dosing pumps. |
![]() |

| 1. Pump housing | Aluminum casting. |
| 2. Recirculation tank and valve | The recirculation valve in the hydraulic system protects the pump head from excessive pressure in the system by opening at a set pressure and discharging oil to the recirculation tank, then re-engaging it via a reset valve when the system pressure returns to the working pressure value. |
3. Diaphragm rupture detection system![]() |
SD series dosing pumps are built with a pump head that features two PTFE diaphragms and a stainless steel separating ring placed between them. At the top of the ring there is a nipple and a one-way valve, which at the customer’s request can be connected to a pressure gauge or a pressure switch, which can indicate whether one or both of the two diaphragms are damaged. |
| 4. Pump head | Pulls liquid from the inlet valve and pushes it through the discharge valve using a PTFE diaphragm. Various multi-head units are available upon request. Each pumping element has independent adjustment while running or stopped. |
| 5. Regulation | Regulating the flow rate is possible while the pump is running or stopped. The movement of the diaphragm is based on a precise piston gear, which ensures accurate volumetric displacement. Stroke adjustment can be performed as follows:
|
| 6. Reducer assembly and transmission | Reduces the motor’s number of revolutions to the number required for dosing by converting rotary motion into linear reciprocating motion using an eccentric shaft, with a slider and return spring. The transmission has a flexible coupling. |
| 7. Electric motor | Three-phase or single-phase (CVE – Ex – Gr. B14 – Cl. F- 50/60 Hz- IP 55 or higher). |
| Hydraulic elements | Plastic or metal depending on product compatibility. |
![]() |
The RAPIDA 2.0 system is a combination of a three-phase asynchronous electric motor and an inverter board, designed to enable motor speed control. Equipped with an LCD display, a control system and a multitude of functions that allow for immediate change of pump settings. Functions:
|
Availability of the Rapida 2.0 system for individual Doseuro dosing pump models:
| Pomp model: | RAPIDA2.0 0.2 0.25 kW |
RAPIDA2.0 0.3 0.37 kW |
RAPIDA2.0 0.5 0.55 kW |
RAPIDA2.0 0.7 0.75 kW |
| D050N | – | – | – | |
| D100N | – | – | ||
| D101N | – | – | ||
| D121N | – | – | – | |
| D122N | – | – | ||
| A-B-BR-SD 125N | – | – | – | |
| A-B-BR-SD 175N | – | – | ||
| A-B-BR-SD 250N | – | – | ||
| A350N | – | – | – |


Safety valves
A safety valve is installed on the pump’s discharge pipe and is connected to the bypass pipe as a safety device, so that it opens (discharges) when the limit value is reached to protect the installation and pump from pressure overload.

Relief and check valves
A check valve is installed on the pump’s discharge line to counteract existing pressure on the suction side, preventing backflow. The use of this valve allows for flow regulation in cases where the discharge pressure is low or non-existent.
A relief valve is installed on the pump’s discharge pipe and connected to a bypass pipe as a safety device, so that it opens (discharges) upon reaching a limit value to protect the system and pump from pressure overload.

Pulsation Dampeners – HSTX Type
316 stainless steel housing, consisting of two parts connected by a special closure, which under dynamic pressure tends to close automatically. Design compliant with ASME VIII° Div. 1. 1.

Pulsation Dampeners – HSTPVC type
PVC body, consisting of two parts connected by a special hose, which under dynamic pressure tends to close automatically: + 50 °C. The membranes are compatible with the process liquid.

Polyethylene tanks
They are suitable for mounting with a dosing pump on top.

Calibration columns
A calibration column is installed on the suction line of a metering pump. It consists of a graduated cylinder. Its function is to determine the flow rate of the pump by checking the volume of liquid drawn in a given time, under actual operating conditions.
| Pump performance | Qmax = 1068 l/h | |
| Max. discharge pressure: | 14 bars 40 bars in the “HP” high-pressure version |
|
| Motor power: | 0.18, 0.25, 0.37, 0.55 or 0.75 kW, 1/3-phase, 1400 rpm | |
| Head material: | AISI 316L stainless steel, PP, PVC or PVDF | |
| Valve ball material: | AISI 316L stainless steel or “PYREX” glass | |
| Valve seat material: | AISI 316L stainless steel or PVDF | |
| Membrane material: | double PTFE membrane | |
| Valve O-ring Material: | FPM | |
| Connection types*: | ½”, ¾”, 1” male BSP *other connection types available on request |
|