Date: 1 May 2025
Pumps drive precision in automated chemistry. They control flow rates, deliver reagents, and maintain pressure across systems—from benchtop flow reactors to integrated microfluidic platforms. Each pump type offers distinct performance trade-offs in terms of pulsing and chemical compatibility. Selecting the right model depends on how tightly your process demands control. This guide maps out the core pump technologies used in lab-based processing – batch and continuous – and flow chemistry, explaining their mechanics, advantages, and where each excels.
Why Laboratory Pumps Matter
At its core, a pump’s job is simple: move fluid from point A to point B. But in the lab, that task often comes with nuance. You may need to:
- Deliver low volumes with extreme precision
- Maintain stable flow against back pressure
- Handle corrosive or viscous fluids
- Work continuously for extended runs
Different pump technologies are tailored to different requirements. Below, we explore the key types of pumps you’ll encounter in a modern laboratory.
Peristaltic Pumps: Flexible, Chemical-Resistant Workhorses
How it works:
A rotor compresses flexible tubing in a wave-like motion, pushing fluid forward without the fluid ever contacting the pump mechanism itself.
Key features:
- Tubing is the only wetted part—ideal for corrosive or sterile fluids when there is a need to exclude air or moisture (e.g. organometallic reagents)
- Can handle slurries and gases in liquid phase
- Simple maintenance (just replace the tubing)
- Pulsations which worsen under pressurised conditions–but some pumps, like the Vapourtec SF-10 pump, can minimize these
Use cases:
- Biological media, acids, solvents
- Flow chemistry, where chemical compatibility is critical
- Slurry or gas-liquid reagent delivery
In context:
The Vapourtec V-3 pump is a chemically resistant peristaltic pump capable of smooth, reliable delivery at pressures up to 10 bar—even with slurries or gas-evolving mixtures. It’s an excellent example of how advanced peristaltic design solves traditional flow and compatibility limitations.
Syringe Pumps: Precision at Micro Scale
How it works:
A motor-driven plunger moves within a syringe barrel, delivering liquid with highly controlled flow rates.
Key features:
- Exceptional accuracy at low flow rates (µL to mL/min)
- Ideal for microfluidics and precise reagent dosing
- Requires syringe refilling or dual-syringe systems for continuous use
- Minimal pulsation until the syringe is required to refill
Use cases:
- Feeding photocatalysts or specialty reagents in microreactors
- Drug delivery studies
- Precise, low-volume applications
Good to know:
While syringe pumps shine in precision, they’re less practical for long-duration or high-volume processes due to refill limitations.
Piston (HPLC) Pumps: Power and Precision Combined
How it works:
Dual pistons alternately draw and push liquid through check valves, creating a continuous, high-pressure flow.
Key features:
- Excellent for high-pressure and pulse-free flow
- Compatible with a wide range of solvents
- Requires periodic maintenance (seal and valve wear) due to its inability to handle biphasic solutions or solutions containing particulates
Use cases:
- HPLC and analytical systems
- High-pressure flow chemistry
- Supercritical fluid delivery
- Any application requiring high stability at >20 bar
In flow chemistry:
Systems like the Vapourtec R-Series use modular piston pumps with options for acid-resistant or high-performance configurations – ensuring optimal compatibility with demanding chemistries.
Diaphragm Pumps: Vacuum and Dosing Solutions
How it works:
A diaphragm flexes back and forth, changing chamber volume to draw in and expel fluid. One-way valves direct flow.
Key features:
- Good for gas/vacuum or low-pressure dosing
- Chemically resistant if built with Teflon/PTFE materials
- Pulsed flow; limited by variable flowrates depending on pressure
Use cases:
- Vacuum filtration or evaporation setups
- Low-pressure dosing of corrosive chemicals
- Portable, oil-free alternatives to rotary vane vacuum pumps
Note:
In reagent delivery, diaphragm pumps are less common than peristaltic or piston types, but they’re useful in auxiliary roles or where low-cost chemical compatibility is needed.
Gear Pumps: Steady Flow for Viscous Fluids
How it works:
Two meshing gears trap fluid between teeth and casing, moving it from inlet to outlet in a smooth, rotary action. These are used in conjunction with mass flow meters.
Key features:
- Continuous, low-pulse flow
- Handles moderate viscosities
- Limited chemical compatibility as flow rate is dependent on viscosity and delivery pressure
Use cases:
- Pilot-scale systems
- Viscous reagent delivery
- Applications needing steady, mid-pressure flow
Caution:
Gear pumps often aren’t used in analytical-scale labs due to size and compatibility, but they serve a role in process development and scale-up.
Centrifugal Pumps
How it works:
An impeller spins fluid outward by centrifugal force.
Key features:
- High flow, low pressure
- Not designed for metered dosing
- Useful in recirculation or bulk transfer setups
- Can have excellent chemical resistance
Use cases:
- Water circulation in cooling systems
- Bulk transfers in pilot plants
Choosing the Right Laboratory Pump: Why Variety Exists
There’s no one-size-fits-all pump. Each has its niche. Some pumps offer unmatched chemical resistance, others deliver high pressure with pinpoint precision. That’s why even a single flow chemistry platform may use different pumps depending on the task.
For example:
| Pump Type | Flow Rate Range | Max Pressure | Flow Stability | Ideal For |
|---|---|---|---|---|
| Peristaltic | Low–medium (0.02–250 mL/min) | ~10 bar | Moderate | Corrosive fluids, slurries, biocompatible tasks, multi-phase fluids |
| Syringe | Very low (µL–100 mL/min) | ~10 bar | High | Microfluidics, precise dosing, single phase fluids only |
| Piston (HPLC) | Low–medium (0.02–250 mL/min) | >200 bar | Very high | High-pressure chemistry, chromatography, single phase fluids only |
| Diaphragm | Low-medium (0.02–1000 mL/min or vacuum) | ~10 bar | Poor | Corrosive liquids, vacuum generation, pulsed flow, requires a mass flow meter for accurate dispensing. |
| Gear | Medium–high (10–500 mL/min) | ~20 bar | High | Viscous or bulk fluid transfer, requires a mass flow meter for accurate dispensing |
Final Thoughts
Pump performance sets the baseline for flow chemistry reliability. Flow rate stability, pressure control, and chemical resistance all shape experimental outcomes. At Vapourtec, we engineer pumps to meet these exact demands. The piston pumps handle aggressive solvents without degradation. The V-3 and SF-10 deliver steady, pulse-free flow under high back pressure. Both systems support precise, scalable synthesis. To explore their capabilities in detail, visit our product pages or contact our team for application-specific guidance.