A pump refers to a device used to lift or transfer fluids—such as liquids or gases—over long distances, from lower to higher elevations, or from low-pressure to high-pressure areas.
While many different structures and mechanisms exist, metering pumps (Constant flow pumps) are specifically used when a liquid must be delivered at a fixed flow rate or velocity. They are essential in fields such as food, pharmaceuticals, biotechnology, chemical synthesis, and semiconductors, serving a wide range of applications from laboratory research to full-scale production lines.
Key Selection Points for Pump Specifications and Performance
The selection points for metering pump specifications and performance are as follows.
Flow Rate This refers to the volume of the pump can deliver per unit of time. (Units: mL/min, L/h, etc.)
Discharge Pressure This refers to the pressure that the pump applies to the liquid. (Unit: Pa, etc.) The “pressure” converted into the height to which water can be lifted is called “Lifting height”. (Unit: m)
Dosing Accuracy (Constant Flow Characteristics) Maintains stability and reproducibility by delivering fluid at a constant flow rate and velocity.
Pulsation This refers to flow in which the flow rate changes periodically, or flow characterized by pulsation.
Self-priming Ability There are pumps that can “suction (self-prime) and discharge even if the pump interior is not filled with liquid” at startup, and pumps that “cannot start unless they are filled with liquid.”
Resistance to Fluids Material and structural suitability depends on the type of fluid being transferred (e.g., water, solvents).
Types of Metering Pump (Constant Flow Pump)
There are several types of “Metering pumps,” primarily categorized as follows.
Displacement
Types
Major pump
Flow rate
Discharge pressure
Dosing accuracy
Pulsation
Self-priming
Positive displacement
Rotary pump
Peristaltic pump
Small to Medium
Low
Excellent
With pulsation
Yes
Vane pump
Gear pump
Screw pump
Reciprocating pump
Piston pump
Small to Medium
Medium to High
Excellent
With pulsation
Yes
Plunger pump
Diaphragm pump
Non-positive displacement
Centrifugal pump
Volute pump Turbine pump
Large
Low to Medium
Medium
Pulse-free
No
Propeller pump
Axial pump Mixed flow pump
Low
Viscous pump
Cascade pump
Low
Peristaltic Tubing Pump “MP Series”
EYELA’s best-selling pump and the industry standard for tubing pumps. A comprehensive lineup of 20 models is available.
Compact and versatile for a wide range of liquid transfer applications.
Flow rate range
9 to 900 (mL/h)
Max. discharge pressure
196（kPa）
Number of channels
1 (NRO-1000), 3 (NRP-2000A)
Applicable tubing
OD 3.2, 4.2, 5.2 (mm)
Integrated tube case structure for easy tubing replacement.
The integrated tube case structure allows for tubing replacement simply by lifting the tubing case.
Clockwise and counter-clockwise rotation can be toggled with a switch.
NRP-1000 features a compact design with a width of only 73mm.
NRP-2000A features three tube case stages, with the second and third stages independently adjustable and lockable at 90-degree increments.
Since the suction and discharge directions can be aligned, tubing can be installed at the optimal length without excessive routing or kinking.
Equipped with a digital rotation display and a rapid switch for maximum flow rate, allowing for quick priming of the tubing line.
Includes external signal input terminals, enabling discharge flow control via electrical signals.
〈Option〉A leak sensor set detects leaks caused by tube ruptures or other failures and automatically stops the liquid transfer.
Peristaltic pumps (Roller pumps) NRP-2000B
High-flow rate type equipped with essential functions.
Flow rate range
0.7 to 66 (L/h)
Max. discharge pressure
137.3（kPa）
Number of channels
1
Applicable tubing
OD 7.94, 9.53, 11.1 (mm)
Integrated tube case structure for easy tubing replacement.
Switchable clockwise and counter-clockwise rotation.
Digital rotation display. Equipped with a rapid switch for maximum flow rate, allowing the tubing line to be primed quickly.
Includes external signal input terminals, enabling discharge flow control via electrical signals.
The tube case can be rotated and fixed at 90-degree increments. By aligning the suction and discharge directions, you can prevent improper routing or kinking of the tubing.
〈Option〉The leak sensor set detects leaks, such as when a tube ruptures, and stops the liquid transfer.
Peristaltic pumps (Roller pumps) NRP-3000 / 3000P
Compatible with three different tubing sizes and offers a wide range of features. Note: P-types are equipped with a chemical-resistant PPS tube case.
Flow rate range
11.7 to 2300 (mL/min)
Max. discharge pressure
137.3（kPa）
Number of channels
1 , 2 to 3 (Options)
Applicable tubing
OD 7.94, 9.53, 11.1 (mm)
Three types of tubing can be installed without needing to replace the tube retainer for each size.
Since the tubing case and tubing holder are integrated, there is no risk of losing the tubing case.
Features a multi-turn volume setting and digital display. Supports clockwise and counter-clockwise rotation. Equipped with a rapid switch and external signal input terminals.
The tubing case can be rotated and fixed at 90-degree increments. By aligning the suction and discharge directions, you can prevent improper routing or kinking of the tubing.
〈Option〉Up to 2 or 3 channels can be configured by adding multi-stage tubing cases. Tubing of different diameters can also be installed simultaneously.
〈Option〉The leak sensor set detects leaks, such as in the event of a tube rupture, and automatically stops the liquid transfer.
Introducing Peristaltic Pumps (Roller Pumps): NRP-3000 and NRP-3000P Series
Tubing for Peristaltic Pumps
You can select the tubing material from PharMed® BPT, Silicone, Tygon®, or Versilon® (Fluran®) to suit your specific application. Please click here for more details.
