Comparing Different AODD Variants: The Proof is in the Pump

Related Vendors

Lutz Pumpen GmbH

Angst+Pfister AG

Anton Paar GmbH

Pump Solutions Group (PSG)

Wilden Pump & Engineering, LLC

Although the technology is more than 50 years old, AODD pumps can be made more efficient by recent ADS developments that better control the air flow and prevent wasteful air overfilling, which will reduce air consumption, and operating and maintenance costs.

Two primary methods have been introduced to control airflow and prevent overfilling by cutting off the air supply to the air chamber before the end of the pump cycle: electronically controlled and mechanically actuated ADSs.

Air-operated double-diaphragm (AODD) pumps have only a few wetted parts and are driven by compressed air rather than an electric motor. (Picture: Wilden)

The Benfits and Shortcomings of Electronic Pump Controll

Electronic control has two shortcomings. First, the electronics raise an entirely different set of maintenance and operational concerns, including prohibition of use in explosive environments like mines and an inability to be submerged. Second, this electronic ADS technology requires a ‘learning period’ of 30 to 40 seconds where it monitors the operation of the pump before it can estimate when to cut off the air supply prior to the end of the stroke. This can result in erratic and sometimes wasteful flow rates during this learning period.

During the time period from the end of each stroke to the completed shift of the valve, the air is allowed to ‘overfill’ the air chamber without any corresponding displacement of fluid. This volume of compressed air is entirely wasted.

The race is on for AODD pumps to move volume faster and more cost effectively. In head-to-head comparisons with the competition, the Wilden Pro-Flo Shift Air Distribution System proved it is not just an incremental improvement in ADS technology, but an entirely new way of looking at how pneumatic pumps operate
(Picture: Pump Solutions Group)

A Mechanical Alternative for AODD Pumps

The mechanically actuated methodis a simple yet extremely effective way to control the air with each stroke and prevent wasteful overfilling. The air is mechanically controlled on a constant basis to maximize efficiency, minimize complexity and maintenance considerations, and allow for operation in explosive and submerged pumping environments.

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