The compressed air in the coaxial exchanger (A), which flows behind one of the two diaphragms, causes it to compress the pump chamber and the medium flows to the output side (B).

At the same time, the membrane on the opposite side, which is integrated in the coaxial exchanger, creates a negative pressure that sucks in the medium on the inlet side (C).

As soon as a cycle is completed, the compressed air flows in the coaxial exchanger behind the opposite membrane and the cycle is reversed.


• Pumping of aggressive and flammable substances, viscous liquids also with solids and media containing gas.

• Especially suitable for use in hazardous areas (ATEX certification).

• Reliability even at high humidity.

• Adjustable flow rate and head via air pressure.

• Suitable for continuous operation.

• Dry-running without any problems.

• Dry self-priming.

• Flow rate and head can be adjusted by the compressed air.

• Three suction and delivery connections.

• Operation with non-lubricated air.

• Manifolds can be separated. Therefore two different media can be pumped at the same time.

• Easy replacement of spare parts and maintenance by your service department.

The pumps are characterized by a high level of operational reliability and their diverse applications.

The air-operated diaphragm pumps can be used for almost any low to high viscosity media, whether neutral or aggressive, whether flammable or abrasive, with or without solids, whether used with or without gas components.

A wide range of different pump materials ensures optimum chemical resistance to the media be pumped, and the optimum thermal resistance with a view to the liquid or ambient temperature.

Because of their design principle, the air operated diaphragm pumps are qualified for a variety of difficult applications, especially in damp or hazardous locations.

Automotive technology • Chemical industry • Mechanical engineering • Paints and varnishes • Printing inks • Textile industry • Ceramics industry • Mining • Water treatment • Pharmaceutical and cosmetic industry • Food industry • Pulp and paper industry • Biodiesel oil & gas industry • Electroplating industry • etc.

Versions, accessories

The casings of most diaphragm pumps are available in PP, PVDF, aluminium and stainless steel.

In addition to a series with an approval for Ex Zone 2, we can also offer you another with ATEX certification for Ex Zone 1.

Accessories for air operated pumps such as hose connections, hoses or pulsation dampeners are available.

The pumping principle of diaphragm pumps

is proven for decades and is suitable for most applications.

The diaphragm pumps are among the group of positive displacement pumps. They are powered by an air motor. By the motor the two membranes, that are interconnected by a pump shaft, are moved back and forth by the compressed air with is introduced alternately into the air chambers behind the membranes. The switching process takes place automatically by a control valve, that switches if a membrane has reached the end position.

While the diaphragm on the one side of the pump shaft displaces the medium through the introduced compressed air, the membrane simultaneously creates a negative pressure on the other side. As a result, new medium flows into the pump chamber and is also displaced in the next pump cycle. The pump chamber, in which the medium is located, is alternately closed and opened by the ball valves (consisting of: balls, ball sockets and O-rings in different materials).

Different materials as well as our decades of experience in the pump division guarantees high reliability and long life of the pump.

Components of the pump

A = Balls, ball seats, O-rings
B = Pumping chamber
C1 = Product-side diaphragm
C2 = Air-side diaphragm

D = Suction connection
E = Delivery connection
F = Pneumatic exchanger

800.5 800.16 800.30 800.50 800.90 800.91 800.150 800.220 800.340 800.341 800.650 800.850
Materials PP PP, ECTFE PP, PVDF, Alu, SS PP, PVDF, Alu, SS SS PP, PVDF, Alu PP, PVDF, Alu, SS PP, PVDF, Alu, SS PP, PVDF Alu, SS PP, PVDF, Alu, SS PP, PVDF, Alu, SS
Connections 1/4″ 3/8″ 1/2″ 1/2″ 1″ 1″ 1″ 1 1/4″ 1 1/2″ 1 1/2″ 2″ 3″
Air connections 1/8″ 3/8″ 1/4″ 3/8″ 3/8″ 3/8″ 3/8″ 1/2″ 1/2″ 1/2″ 1/2″ 3/4″
Head dry 3 m 2 m 6 m 5 m 6 m 6 m 5 m 5 m 6 m 6 m 4 m 5 m
Max. flow rate 5 l/min 17 l/min 30 l/min 50 l/min 100 l/min 100 l/min 150 l/min 220 l/min 340 l/min 340 l/min 650 l/min 900 l/min
Max. head 70 m 70 m 70 m 70 m 70 m 70 m 70 m 70 m 70 m 70 m 70 m 70 m
Solids 0,5 mm 2 mm 4 mm 4 mm 4 mm 4 mm 5 mm 6 mm 6 mm 8 mm 10 mm
Operating pressure 7 bar 7 bar 7 bar 7 bar 7 bar 7 bar 7 bar 7 bar 7 bar 7 bar 7 bar 7 bar