What is a diaphragm pump?

A diaphragm pump uses a thin film to separate the fluid being transported from the actuator and pump chamber, thereby protecting them. The part of the diaphragm that contacts the fluid on the left side is made of corrosion-resistant material or coated with a layer of corrosion-resistant substance, while the right side of the diaphragm is filled with water or oil.

Main materials:

Diaphragm pumps, also known as control pumps, are the main types of actuators. They change fluid flow by accepting control signals output by the control unit and using power operation. The role of diaphragm pumps in the control process is to accept control signals from regulators or computers, change the flow of the medium being adjusted, and maintain the adjusted parameters within the required range, thereby achieving process automation. When comparing automatic control systems with manual adjustment processes, the detection unit is like the human eye, the control unit is like the human brain, and the actuator—diaphragm pump—is like the human hands and feet. To achieve control over process parameters such as temperature, pressure, flow rate, liquid level, etc., in the production process, diaphragm pumps are essential.

Pneumatic diaphragm pumps commonly use five materials: plastic, aluminum alloy, cast iron, stainless steel, and Teflon. Electric diaphragm pumps use four of these materials: plastic, aluminum alloy, cast iron, and stainless steel. Diaphragm pump diaphragms are made of different materials such as nitrile rubber, neoprene rubber, fluorine rubber, polytetrafluoroethylene, polytetrafluoroethylene, etc., and are used in various special occasions to pump various media as needed.


Due to the characteristics mentioned above, pneumatic diaphragm pumps have gradually penetrated the market of other pumps since their inception and occupy an important part of it. For example, in the paint and ceramic industries, diaphragm pumps have an absolute dominant position.


  1. Pumping peanut butter, pickles, mashed potatoes, sausages, apple jam, chocolate, etc.
  2. Pumping paint, gum, pigments.
  3. Adhesives and glue of all kinds can be pumped.
  4. Various tiles, ceramics, brick products, and glazes.
  5. After drilling oil wells, pumping sediments and grouting with pumps.
  6. Pumping various emulsifiers and fillers.
  7. Pumping various sewage.
  8. Using pumps to clear sewage from oil tankers and barges.
  9. Thin slurry of hops and yeast, syrup, molasses.
  10. Pumping water from mines, tunnels, tunnels, ore dressing, and slag.
  11. Pumping cement grout and mortar, various rubber slurry.
  12. Various abrasives, corrosives, petroleum and mud, cleaning scale and general containers.
  13. Various highly toxic, flammable, volatile liquids.
  14. Various strong acids, strong alkali, strong corrosive liquids.
  15. Various high-temperature liquids can withstand up to 150 degrees Celsius.
  16. As a primary pressure feeding device for various solid-liquid separation equipment.


Diaphragm pumps can be classified into pneumatic, electric, and hydraulic types according to the power source used by their actuators, namely pneumatic diaphragm pumps powered by compressed air, electric diaphragm pumps powered by electricity, and hydraulic diaphragm pumps powered by liquid media (such as oil) pressure.


Parameters of pneumatic diaphragm pumps.

型 号 流量
















QBY-10 0~0.8 0~50 6 5 1 7 0.3
QBY-15 0~1 0~50 6 5 1 7 0.3
QBY-25 0~2.4 0~50 6 7 2.5 7 0.6
QBY-32 0~6 0~50 6 7 4.0 7 0.6
QBY-40 0~8 0~50 6 7 4.5 7 0.6
QBY-50 0~12 0~50 6 7 8 7 0.9
QBY-65 0~16 0~50 6 7 8 7 0.9
QBY-80 0~24 0~50 6 7 10 7 1.5
QBY-100 0~30 0~50 6 7 10 7 1.5



Diaphragm pumps are a new type of conveying machinery that can transport various corrosive liquids, liquids with particles, high viscosity, volatile, flammable, and highly toxic liquids. Diaphragm pumps are available in four materials: plastic, aluminum alloy, cast iron, and stainless steel.

Diaphragm pumps use different diaphragm materials according to different liquid media, including nitrile rubber, neoprene rubber, fluorine rubber, polytetrafluoroethylene, polytetrafluoroethylene, to meet the needs of different users. They are used in various special occasions to pump media that conventional pumps cannot handle, achieving satisfactory results.

In the paint and ceramic industries, diaphragm pumps have an absolute dominant position. The advantages of pneumatic diaphragm pumps are:

  1. Due to the use of air as the power source, the flow automatically adjusts with the back pressure (outlet resistance) changes, suitable for medium and high viscosity fluids. In contrast, the working point of a centrifugal pump is set based on water, so if used for slightly higher viscosity fluids, it would require a reducer or frequency converter, significantly increasing costs, which also applies to gear pumps.
  2. In environments prone to flammability and explosion, pneumatic pumps are reliable and low-cost, such as in the transportation of fuel, gunpowder, and explosives. This is because: first, sparks cannot be generated after grounding; second, no heat is generated during operation, so the machine does not overheat; third, the fluid does not overheat because diaphragm pumps have minimal agitation of the fluid.
  3. In harsh environments such as construction sites, wastewater discharge from factories and mines, where sewage contains many impurities and complex components, pipelines are prone to blockage. This can lead to high loads on electric pumps and overheating of motors. Pneumatic diaphragm pumps can handle particles and have adjustable flow, automatically stopping when the pipeline is blocked until it clears.
  4. They can be used to transport chemically unstable fluids, such as photosensitive materials and flocculants. This is because diaphragm pumps have low shear forces and minimal physical impact on materials.
  5. In handling hazardous and corrosive materials, diaphragm pumps completely isolate the material from the outside world.
  6. They can ensure that raw materials are not contaminated with impurities in some experiments.

Additionally, diaphragm pumps are small in size, easy to move, do not require a foundation, occupy a small footprint, and are easy and economical to install. They can be used as mobile material conveying pumps.