Piston Diaphragm Pump

Icon - Piston Diaphragm Pump shadow

Piston diaphragm pumps are robust all-rounders and can therefore be used in many ways. They convey critical and environmentally hazardous fluids safely and reliably: Regardless of whether abrasive, aggressive or toxic media, this by the diaphragm seperated pump chamber protects machine, people and the environment.

Here’s an overview of how a piston diaphragm pump works and all of its relevant characteristics.

Delivery characteristics of the piston diaphragm pumps
from our alliance members

Delivery rate:  0.001 up to 1,350 m³/h  (0.004 up to 5,943 gal/min)

Delivery head:  up to 3,500 m  (up to 11,483 ft)

Pressure:  up to 350 bar

Viscosity:  0.1 up to 10,000 mPas

Temperature:  -20 up to +200 °C  (-4 up to +392 °F)

Solids:  up 80 %  (max. 20 mm particles)


partially self-priming

API standard available

Operating principle of a piston diaphragm pump

The technical principle of a piston diaphragm pump corresponds to that of a piston pump: The fluid to be conveyed is actively displaced by the compression of a piston. Here, the working chamber is separated by a diaphragm. The piston thus penetrates only the working medium, which presses against a diaphragm. The corresponding compression is transferred to the fluid and presses it out of the working chamber. Valves prevent flow in the wrong direction. With the movement of the piston out of the pump housing, the inlet valve opens, and fluid is sucked into the cylinder. When the piston moves back into the housing, the outlet valve opens, and the medium is conveyed out of the pump.

The particular feature of the piston diaphragm pump is a hermetically sealed, leak-free oscillating membrane, which seals the media chamber against the environment. The especially secure double hose-diaphragm pumps have a redundant diaphragm: In the pump head, there are two diaphragms one inside the other, which surround the liquid and doubly separate the hydraulic end of the drive. The conveyed medium streams straight through the pump and only comes into contact with the inside of the working chamber and the check valves. Erosion and corrosion are thus reduced to a minimum with such diaphragm pumps.

As with common piston pumps, piston diaphragm pumps are also available with one or more pump heads. Depending on the size and number of the working chambers with diaphragms that are used in parallel, they can also achieve large capacities and pressures.

Benefits of piston diaphragm pumps & their applications

Benefits with regard to safety and wear

The main benefit of diaphragm pumps is that only a few components touch the conveyed medium. The hermetic design enables especially safe transport of corrosive or abrasive liquids and sludges, as well as of toxic or aggressive media. In addition to excellent process and operational safety, diaphragm pumps are also especially low-maintenance. Piston diaphragm pumps also convey abrasion-free, hygienically, and without shear at high temperatures.

Manufacturers of high-quality piston diaphragm pumps offer diaphragms in many different materials in order to enable users to convey fluids of all kinds. FDA-compliant materials can also be used, so that the pumps fulfill hygiene requirements and can be used for the manufacturing of food and pharmaceutical products.

As positive displacement pumps, piston diaphragm pumps enable precisely controllable capacities. Their efficiency of more than 90% makes them economical units. In comparison to many other designs, they also save energy. The safety aspect of the pumps is supported by diagnostic systems for permanent condition monitoring. In terms of Industry 4.0, users can therefore exploit the benefits of digitalization, in that they are warned early about pending damage.

Areas of application

Their great focus on operational safety makes piston diaphragm pumps the ideal unit for conveying abrasive, aggressive, and toxic media, environmentally hazardous media and heterogeneous mixtures and sludges, some with a higher percentage of solid content. Areas of application for these pumps are above all industries where safety plays a large role:

•    Chemical industry
•    Food & pharmaceuticals
•    Oil & gas
•    Mining

Thanks to their displacement principle and the associated closed conveying of liquids, piston diaphragm pumps are also ideally suited as process & dosing pumps for precise handling of fluids.



Piston diaphragm pumps – always a good choice

Piston diaphragm pumps are always a good choice for applications where no safety compromises may be made, for they guarantee the greatest process and operational safety and can handle even the most difficult, challenging media without risks. In various designs, they can be used for countless applications, even as dosing pumps or hygiene pumps, and if they are designed as double piston diaphragm pumps, they offer even greater safety. With predictive maintenance, users reliably avoid unplanned breakdowns.

Does your process rely on high-performance, safe, yet gentle conveying of media? Then make a non-binding inquiry!
We’ll be glad to examine it in detail and find the right diaphragm pump for your application.


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