Recent improvements, low maintenance costs can give diaphragm pumps an advantage.
by Erik Solfelt
June 20, 2018

One of the most crucial operations is the transfer of liquids along the production chain.

Due to the importance of the many fluid transfer operations along the breadth of the chemical manufacturing chain, facility operators need to identify the best pumping technology for the job. The technology must possess the versatility to perform reliably and efficiently at any number of points in the production hierarchy.

AODD pumps can offer a number of operational advantages:

  • They are appropriate for use with high-viscosity fluids and can handle fluids that range from water-like to medium and very viscous liquids.
  • They can run dry and strip discharge lines without getting damaged. If the pressures get to be too much, the pump will just stop running, but it will not break.
  • They are simple devices and their control relies solely on solenoid operators, pump cycle counters and surge-dampener assemblies.
  • Their operating costs can be lower when all of the maintenance, accessories and controllers are included, and in many cases their total cost of ownership is lower over their entire operational lifespan when compared to competitive pump styles.

Additionally, some of the AODD pump styles have been designed to be direct bolt-to-bolt and pipe-to-pipe drop-in replacements in existing pumping systems. This makes the AODD pump styles a cost-effective way to upgrade fluid transfer performance while simultaneously realizing the benefits inherent in the operation of an AODD pump that features an advanced air distribution system. These benefits include reduction in air consumption and expense, optimized product handling and containment, and scaled-back maintenance and replacement costs.

Finally, the design and operation of AODD pumps allows them to transfer a wide range of liquids with varying handling characteristics. One of the most prominent is viscosity, or the thickness of the liquid that is being transferred.

The operation of AODD pumps virtually eliminates product slip, regardless of the fluid’s viscosity, since the pump’s ball check valves control fluid transfer. Conversely, gear, screw and lobe pump technologies use fixed tolerances to control slip, which means they are less likely to adequately adjust to viscosity changes.

Image 3. One diaphragm is designedImage 3. One diaphragm is designed with a piston that is integrated into the diaphragm itself. The result is that unlike conventional diaphragms, this diaphragm has no outer piston abrasion, which is a key failure mode for conventional diaphragms and eliminates a potential leak point around the outer piston. This means improved diaphragm life and peace of mind when handling hazardous liquids.

Pump Construction

Quality pump construction is key when handling dangerous chemicals, and using a pump designed with the right materials is important to the safety of a plant. To satisfy these demands, AODD pumps are available in a wide range of materials of construction in order to meet a variety of chemical handling needs. Common chemical pump materials include polypropylene, Kynar, stainless steel, ductile iron and Hastelloy, with some companies possessing the capability to offer special materials like super duplex when really unique materials are required to ensure uninterrupted production processes and the safety of plant personnel.

If metal pumps are required, one overlooked material in the chemical processing world is ductile iron, which works well in both acidic and basic pH application ranges of 4 to 10. Provided that the chemical compatibility is correct, operators who use ductile-iron pumps can realize all of the benefits of stainless steel, but at a lower purchase cost.

A bolted design does not, as mentioned earlier, rely on packing or expensive mechanical seals to prevent leaks. In this case, the most important benefit of bolted pumps is their ability to offer one of the highest levels of product containment. This is critical for two main reasons: many raw or finished chemicals are high-value products and any loss through leakage can be detrimental to the operation’s bottom line and, second, most chemicals can be harmful to humans and the environment.

Go-To Technology

Thanks to its simple yet innovative design, the AODD pump has proven to be able to consistently meet the demands of chemical processors while building a reputation as a go-to pumping technology where basic fluid transfer capabilities are required. The AODD pump, which possesses a stable of notable operational characteristics, has become a first-choice technology for chemical manufacturers who are searching for a pump that meshes cost-conscious air consumption with reliable production rates.

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