Solvent transfer pumps provide safe, controlled movement of liquids such as Acetone, Benzene, Ethanol, Hexane, Propanol, Toluene and Xylene. Many solvents are low in viscosity, volatile and capable of forming flammable vapour-air mixtures. Some may also be toxic, corrosive or environmentally hazardous.
AxFlow supplies industrial solvent pumps for tank transfer, drum and IBC unloading, process circulation, loading, recovery and chemical dosing. Available technologies include magnetic drive, canned motor, regenerative turbine, rotary vane and air-operated double-diaphragm pumps.
What Is a Solvent Transfer Pump?
A solvent transfer pump is selected to move an organic solvent safely while maintaining chemical compatibility and controlling leakage, vapour release and ignition risks.
There is no single pump design suitable for every solvent. The correct choice depends on:
- The exact solvent and concentration
- Flow and discharge pressure
- Operating temperature
- Vapour pressure
- Material compatibility
- Required containment
- Suction conditions
- Hazardous-area classification
Why Are Solvents Difficult to Pump?
Flammable Vapours
Many solvents release vapours that can form a flammable atmosphere when mixed with air. Safe handling therefore requires more than an appropriate pump: ventilation, ignition-source control, hazardous-area assessment and suitable operating procedures may also be required.
Under DSEAR, UK employers must assess and control fire and explosion risks arising from dangerous substances such as flammable solvents.
Volatility and Cavitation
Volatile solvents can have relatively high vapour pressures. If pressure at the pump inlet falls too close to the liquid’s vapour pressure, the solvent may flash and cause:
- Cavitation
- Unstable flow
- Reduced pump performance
- Vapour locking
- Loss of prime
The system’s NPSH available must therefore be checked against the pump’s NPSH required across the full operating range.
Chemical Compatibility
Pump casings, internal bearings, containment shells, seals, O-rings, diaphragms and hoses must be compatible with the specific solvent.
Compatibility should be checked using the precise chemical name, concentration and temperature. A material that is suitable for one solvent or concentration may not be suitable for another.
Low Viscosity and Lubricity
Many solvents are thin, poorly lubricating liquids. This can affect product-lubricated bearings and increase internal slip in some positive displacement pumps.
The hydraulic design, materials and internal clearances must therefore be suitable for low-viscosity operation.
Which Pump Is Best for Solvent Transfer?
| Pump technology | Best suited to | Key consideration |
| Magnetic drive pumps | Clean, corrosive, toxic or flammable solvents requiring high containment | Avoid dry running and confirm internal bearing compatibility |
| Canned motor pumps | Continuous process duties where eliminating the dynamic shaft seal is important | Internal cooling, lubrication and vapour conditions must be checked |
| Regenerative turbine pumps | Low-flow, high-head duties involving clean or volatile solvents | Particularly useful where conventional centrifugal pumps provide insufficient head |
| AODD pumps | Drum and IBC unloading, mobile transfer and intermittent duties | Check diaphragm compatibility, pulsation, air consumption and hazardous-area suitability |
| Rotary vane pumps | Loading, unloading and controlled transfer of compatible low-viscosity liquids | Confirm lubricity, vane materials, sealing and pressure limits |
| Centrifugal process pumps | Continuous, higher-flow transfer of clean solvents | Seal arrangement, NPSH and materials must match the duty |
Solvent Transfer Pump Applications
Solvent pumps are used throughout:
- Chemical and Petrochemical Processing
- Paints, Inks and Coatings
- Pharmaceutical and Fine Chemicals
- Tank, Drum and IBC Transfer
- Solvent Recovery and Recycling
- Oil, Gas and Refining
How to Choose a Solvent Transfer Pump
Identify the Exact Solvent
Start with the current Safety Data Sheet and confirm:
- Chemical name and concentration
- Flash point
- Vapour pressure
- Density and viscosity
- Operating temperature
- Toxicity and corrosiveness
- Electrical conductivity
- Potential contamination or solids
Do not select a pump using the general description “solvent” alone.
Define the Pumping Duty
Establish:
- Minimum, normal and maximum flow
- Suction pressure
- Discharge pressure or total head
- Pipework losses
- Duty cycle
- Required priming capability
- Minimum and maximum temperature
Decide the Required Level of Containment
For hazardous, toxic or environmentally sensitive solvents, consider whether the duty requires:
- A mechanically sealed pump
- A double-seal arrangement
- A magnetic drive pump
- A canned motor pump
- Secondary containment
- Leakage detection
Check Materials and Elastomers
Confirm the compatibility of every wetted component, including:
- Pump casing
- Impeller or rotor
- Containment shell
- Internal bearings
- Mechanical seals
- O-rings and gaskets
- Diaphragms
- Hoses and connections
Review Suction and Vapour Conditions
Evaluate the solvent’s vapour pressure, NPSH available, suction lift and risk of gas entering the pump.
Self-priming capability does not guarantee stable performance if the solvent flashes within the suction line.
Assess the Hazardous Area
The pump, motor, controls and accessories must be appropriate for the site’s hazardous-area classification. ATEX certification for one component does not make the complete installation compliant.
Bonding, earthing, ventilation and ignition-source control should be addressed through the site’s DSEAR assessment.
Frequently Asked Questions
What is a solvent transfer pump?
A solvent transfer pump is a pump designed to handle solvents safely and reliably, especially where the liquid is flammable, corrosive, toxic or low in viscosity.
Why are solvents difficult to pump?
Solvents can be highly flammable, may ignite on contact with oxygen, can be corrosive and toxic, and often have low viscosities.
What pump types are used for solvent transfer?
The page highlights magnetically driven pumps and canned pumps as leak-free, high-containment solutions for solvent transfer.
