When it comes to moving fluid for paint or related application you will often be evaluating between an airless piston driven pump or a diaphragm pump. To ensure you select the right type of pump for your application it is important to have a thorough understanding of each type of pump and their applications.

Diaphragm pumps

The material is transported by means of a stroke movement in the diaphragm. Products featuring this technology are robust and yet easy to handle on a construction site or workshop. Pneumatic double diaphragm pumps are ideal for woodworking applications and produce top surface quality. Electrically operated diaphragm pumps can be used as both Airless and AirCoat spray packs.

Piston pumps

Piston pumps transport the material by means of a stroke movement in the piston. This creates high suction performance, making them ideal for highly viscous materials. Some piston pumps are operated pneumatically. This provides protection against explosion and makes them suitable for use in workshops. Our hydraulic piston pumps offer even greater performance and can also be operated using petrol.

Design and function of a diaphragm pump

A plastic diaphragm generates rapid pressure and is generally powered by an electric motor, but there are also pumps operated by compressed air. In addition, an inlet valve and an outlet valve ensure the control of the pressure and uniform material flow. The desired operating pressure is regulated via a control valve. The design is therefore very simple. Further electronic components are not installed. Because of this simple design diaphragm pumps, unlike electric piston pumps, have no mechanism for detecting the pressure requirement and therefore operate as a “permanent rotor”. The pump is, therefore, running non-stop as it is switched on.

Design and function of a piston pump

An electric piston pump is more complex in construction than a diaphragm pump. These pumps are also generally powered by an electric motor (there are also air-operated models, however). By the piston stroke, ie, the movement of the piston, the paint is sucked in. Also with this pump type, valves ensure uniform material flow. As with the diaphragm pump, the piston pump also has a pressure regulating valve to obtain the desired working pressure. In contrast to the diaphragm pump, which functions as a “permanent rotor”, electric piston pumps detect the set operating pressure (eg 120 bar). The pump operates up to this pressure range, the motor switches off as soon as the desired working pressure has been reached. And while spraying, as the pressure drops, the piston pump immediately detects the pressure drop and begins pumping the material until the desired pressure range is reached.

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