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Volumetric Pumps vs. Syringe Pumps

Apr. 16, 2022

Most positive displacement pumps or volumetric pumps move the fluid handled within a closed volume. However, syringe pumps are also volumetric pumps, the difference being that the volume handled is fixed. The differences between classic volumetric and syringe pumps are discussed here to help the reader distinguish and select the right pump for your application.

 

Volumetric pumps

Most volumetric pumps work through two general mechanisms: reciprocating or rotary mechanisms. Engineers use positive displacement pumps for systems that require pressurized fluids, especially in the chemical industry. However, you can find these types of pumps in small plants and factories. The injection system of the engine is another classic type of positive displacement pump. Positive pumps in this mode are traditional piston or plunger pumps.


Volumetric Pumps vs. Syringe Pumps

 

Reciprocating positive displacement pumps

In a reciprocating pump, the displacement body as a piston vessel gradually and periodically increases and decreases the working volume as pumping occurs, so that a volume is delivered from the inlet to the outlet. For this process, the working volume must be kept isolated by separating elements that act as check valves; during pumping, the intrinsic pressure difference controls these elements In the case of rotational mechanics, the rotational speed controls the valves. The main advantage of the isolation device called a valve is to prevent fluid backflow into the suction or discharge line; this function maintains positive displacement. The most common type of displacement pumps are piston pumps / plunger pumps. Their displacement body, such as a plunger, describes the linear motion.

 

Reciprocating positive displacement pumps

With regard to variable volume displacement, these pumps are rotary principle; traditional rotary pumps are gear pumps, screw pumps or peristaltic pumps. In general, such pumps move finite elements, gear pumps perform the process of driving the fluid between the gear teeth, peristaltic pumps perform the same process with the presence of a hose between the rotating elements. As the rotating elements move in different positions, the displacement pattern is slightly different, and after hundreds of operating hours, the displacement of each rotating shaft may not be accurate. However, for peristaltic pumps; it is not recommended to use these pumps for microfluidic characterization.

 

Syringe Pumps

Syringe pumps are volumetric pumps with a fixed volume and usually do not belong to the previous classification. Syringe pumps offer several advantages over standard volumetric pumps: operation at a minimum rate of 1 µl/min, picoliter control, high viscosity and pressure, and flow control. HEDY syringe pumps allow for the most accurate and reliable operation at a wide range of rates.

 

Comparison

In general, all of these pumps allow fluid movement. However, the most important feature to distinguish is the accuracy and rate they can provide. In-plane, syringe pumps are the more useful pumps for microfluidic applications, high-tech development and research applications. According to the previous description, a pump that allows similar control is the peristaltic pump, which also provides no contamination, since the element never touches the fluid. Nevertheless, the hose should be cleaned or sterilized depending on the application. The syringe pump is very intuitive and reliable, although flow fluctuations at low flow conditions (~uL/hr) can be problematic.

 

HEDY solution

HEDY syringe pumps offer a higher standard; these pumps use miniature stepper motors that can be customized for high pressure and high viscosity applications. As a result, HEDY syringe pumps can develop microfluidics for the most exciting areas of biochemistry, biotechnology, materials synthesis and chemical synthesis.

 

Volumetric Pumps vs. Syringe Pumps