Three-stage chemistry-design diaphragm pumps are an excellent solution for continuous, oil-free pumping of corrosive gases and vapors and meet high requirements regarding ultimate vacuum. The three-stage construction provides the advantageous combination of high pumping speed and deep ultimate vacuum in a pump with a very small footprint. All parts in contact with pumped media are made of chemically resistant fluoroplastics. Well-proven PTFE sandwich diaphragms increase reliability and extend operating life. The MD 1C with gas ballast valve is optimally prepared for pumping easily condensable vapors (high boiling solvents). Three-stage chemistry diaphragm pumps are an excellent solution for applications involving corrosive gases and vapors at high vacuum requirements. Typical applications are vacuum generation at rotary evaporators, vacuum concentrators and many other laboratory applications. Due to their excellent ultimate vacuum they are the ideal solution for evaporation of high boiling solvents even with gas ballast. The MD 1C pump is the heart of a whole line of reliable chemistry pumping units.