A diaphragm pump is a type of positive displacement pump that uses a combination of the reciprocating action of a rubber, thermoplastic, or Teflon diaphragm and suitable valves on either side of the diaphragm to pump a fluid. The diaphragm pump is also known as a membrane pump. The pump delivers a hermetic seal between the drive mechanism and the compression chamber, allowing the pump to transfer, compress, and evacuate the medium without a lubricant. The diaphragm pump has the following characteristics:

• Self-priming and have good suction lift characteristics.
• Can be effectively driven by compressed air.
• Hydraulically driven versions are suitable for discharge pressure up to 1,200 bar.
• Internal pump parts can be suspended and isolated within oil to promote pump longevity.
• Can be up to 97% efficient.
• Low to moderate capacity and pressure.
• Very low efficiencies.
• No seal.
• High pulsation.

The diaphragm pump is capable of handling liquids with various levels of viscosity as well as liquids with suspended solids. This type of pump, thanks to the special design configurations and type of materials used, is also capable of safely and efficiently handling particularly aggressive chemicals. The diaphragms are available in a wide variety of materials and designs and act both as a barrier with the task of separating the fluid side of the pump from the air side and contextually to create the pumping action through their expansion. The diaphragm pump is used in many industries, and there is an extensive number of construction materials available to produce many configurations for difficult fluids.