Diaphragm Pump for Oil-Free Vacuum and Chemical-Resistant Fluid Transfer

Diaphragm Pump covers oil-free laboratory vacuum and fluid transfer pumps that use an oscillating flexible diaphragm instead of oil lubrication to move gas or liquid. These pumps are chemically resistant, require minimal maintenance, and generate no oil contamination risk, making them the standard choice for rotary evaporator vacuum, Büchner funnel filtration, SpeedVac concentration, gel drying, and chemical-resistant fluid transfer. Single-stage models achieve moderate vacuum; two-stage models reach deeper vacuum for demanding applications. Laboratories can benefit from guidance when selecting diaphragm pump specifications based on vacuum depth, chemical compatibility, and application requirements.

Looking for a suitable diaphragm pump? Contact customerservice@mbpinc.net to get expert recommendations on vacuum level, chemical resistance, and system configuration for your specific laboratory application.

Diaphragm Pump

Per Page:

Sort By:

No Products Found

Back to home

What is a diaphragm pump?

A diaphragm pump is a positive-displacement pump where a flexible membrane alternately expands and contracts a pump chamber to draw fluid or gas in on the intake stroke and push it out on the discharge stroke, without oil lubrication or sealing. Because no oil is used, diaphragm pumps are inherently oil-free, eliminating oil contamination of samples or solvents and oil disposal requirements, and the PTFE or chemically resistant diaphragm material provides broad chemical resistance. They are the recommended replacement for oil-sealed rotary vane pumps in most standard molecular biology and chemistry vacuum applications.

What you will find:

Air-powered operation for safe and efficient liquid transfer without electricity
High flow rate of 46.2 gpm for demanding fluid handling applications
Double diaphragm design for smooth and reliable pumping performance
Oil-free operation helps reduce contamination risks in sensitive workflows
Self-priming capability for easier startup and operation
Can handle liquids with small solids and slurries for versatile processing
Durable 316 stainless steel body construction for chemical resistance
Suitable for laboratory, chemical handling, and industrial fluid transfer applications
Compact design supports efficient integration into existing workflows

How to choose a diaphragm pump

Choose based on the ultimate vacuum required

Single-stage diaphragm pumps reach ultimate vacuums of 5–15 mbar, suitable for Büchner filtration, gel drying, and aqueous concentration. Two-stage models reach approximately 0.5–2 mbar, adequate for rotary evaporation of common organic solvents and SpeedVac concentration of samples with low boiling point components.

Select PTFE-wetted models for chemical resistance

PTFE diaphragm and valve construction provides resistance to a wide range of organic solvents, concentrated acids, and corrosive gases, making PTFE-wetted models the standard for chemistry and molecular biology labs working with organic solvents and corrosive materials.

Match pumping speed to the connected system volume

Pumping speed in liters per minute determines how quickly the pump evacuates the connected volume from atmospheric to operating pressure. A pump with insufficient pumping speed for a large rotary evaporator flask system will take a long time to reach operating vacuum and may struggle to maintain it.

Consider a chemistry vacuum system with integrated vacuum control

Integrated chemistry vacuum systems combine a diaphragm pump with a vacuum controller that automatically maintains a set pressure, providing more consistent and reproducible rotary evaporation than a pump at full vacuum adjusted manually with a bleed valve.

Check noise level and ventilation requirements

Diaphragm pumps are generally quieter than oil-sealed rotary vane pumps, but noise levels still vary by model. Checking the decibel specification and whether the pump exhaust requires ventilation is important for bench placement.

Specifications context

Diaphragm pumps are characterized by ultimate vacuum and pumping speed, with two-stage models achieving deeper ultimate vacuum by routing the first stage exhaust into a second stage in series. As of 2026, PTFE-diaphragm two-stage chemistry pumps with integrated vacuum controllers have become the standard vacuum solution for rotary evaporator setups in synthetic and analytical chemistry labs, replacing oil-sealed rotary vane pumps due to lower maintenance, eliminated oil disposal obligations, and adequate vacuum for routine evaporation and concentration.

Contact our team at MBP to get advice on choosing the proper diaphragm pump system.

FAQ

Oil-sealed rotary vane pumps require regular oil changes, can back-stream oil contaminating samples and solvents, and require oil disposal, while diaphragm pumps are oil-free, eliminating contamination risk and most maintenance burden. Diaphragm pumps can also pump solvent vapors directly without oil degradation, making them the preferred choice for most chemistry and molecular biology vacuum applications.

Single-stage diaphragm pumps achieve ultimate vacuums of 5–15 mbar, suitable for Büchner filtration, gel drying, and aqueous concentration. Two-stage models achieve 0.5–2 mbar, adequate for rotary evaporation of most common organic solvents and SpeedVac concentration where lower pressures improve evaporation rates.

PTFE-diaphragm pumps are designed to handle organic solvent vapors including ethanol, acetone, methanol, and dichloromethane, since the PTFE diaphragm and valves are chemically resistant. An oil-sealed pump would rapidly degrade its oil when exposed to solvent vapors, while a PTFE diaphragm pump operates continuously with solvent exposure without the same degradation.

A two-stage diaphragm pump connects two stages in series so the exhaust from the first stage feeds into the inlet of the second, achieving deeper ultimate vacuum than a single-stage design. Two-stage models are needed for applications requiring vacuum below 5–10 mbar, such as rotary evaporation of higher-boiling solvents, SpeedVac concentration of heat-sensitive samples, or providing rough vacuum to a lyophilizer.

Pumping speed is the volume of gas the pump removes per unit time at a specified pressure and determines how quickly the connected volume is evacuated from atmospheric to the desired operating vacuum. Selecting adequate pumping speed for the connected system volume ensures operating vacuum is reached quickly and maintained against leaks or gas load from evaporation.

A diaphragm pump connects to the rotary evaporator vacuum port via chemically resistant vacuum tubing, typically PTFE or thick-walled silicone, with optional inline solvent vapor traps between the condenser and pump inlet to capture uncondensed vapors before they reach the pump. A vacuum controller between pump and evaporator allows the vacuum level to be set and maintained automatically.

Diaphragm pumps require less maintenance than oil-sealed pumps — no oil to change or dispose of — but the diaphragm and valve discs eventually wear and need periodic replacement, typically every 2000–4000 operating hours. Manufacturers offer maintenance kits with replacement diaphragms and valves installable without specialized tools or factory service.

Yes, MBP offers competitive pricing for single-stage and two-stage PTFE diaphragm vacuum pumps and chemistry vacuum systems, with specialist support for matching specifications to your application. Contact MBP's US office in Houston, Texas, for pricing in both USD and CAD.

We provide the highest quality of products and anytime customer service.

Featured Categories

Useful Links

+1 416-549-8100

customerservice@mbpinc.net

online payment

fast delivery

technical support

24/7 support