Air-operated double-diaphragm (AODD) pumps are an investment that pays off with proper installation and maintenance.
While AODD pumps are known for their reliability, durability, and versatility, there are things you can do during installation that will make them even more efficient.
In this blog, we’ll discuss AODD pump installation tips to avoid downtime and damage—before fluid ever begins to flow through your pump.
Choose the Right Pump Position Within the System
A pump's location within the system is critical to its performance and longevity. This is because AODD pumps can be used in three main ways:
1) Suction Lift
AODD pumps are self-priming, pulling a suction lift up to 32’ (9.8m). In some instances, the pump must be placed above the fluid, which is then pulled into the unit. Ideally, the length of the suction pipe is as short as possible.
WHY THIS MATTERS: This helps with priming while reducing stress on the pump’s diaphragms.
2) Submerged Suction
AODD pumps can be submerged in the fluid that is being pumped. Before submersion, however, you need to ensure that all pump materials, including hardware, are compatible with the fluid and that the pump's air exhaust is above the fluid level. A suction screen is recommended if solids are present in fluid.
WHY THIS MATTERS: This ensures that solids larger than the pump can handle don't enter the unit.
3) Flooded Suction
In this scenario, there is fluid pressure coming into the AODD pump. The pump center line is below the fluid being pumped in this scenario. It's important to place the pump as close to the fluid vessel as possible, reducing the length of the suction line.
WHY THIS MATTERS: This will reduce diaphragm stress and valve ball chatter. Controlling the fluid pressure coming into the suction side of the pump is also important; ideally, it should be less than 10’ of pressure. If the inlet pressure (NPSHA) is greater than 10’ (3.04 m), you should consult the pump manufacturer.
Calculate the NPSHA for a Flooded Section
To calculate NPSHA, you need to know:
- Absolute pressure on or at the liquid surface
- Static head, which is simply the vertical distance from the top of the water surface to the pump impeller eye (or pump centerline if they are the same)
- Vapor pressure of the liquid being pumped, which you can easily calculate based on the temperature and is a value that is easy to look up
- Friction head
NPSHA = absolute pressure - vapor pressure + static head - friction
Properly Size Pump Fittings
Make sure the fluid inlet and outlet piping/fitting are at least as large as the pump’s connection size. This means if you are installing a 2” pump, it should be connected to a 2” or larger piping.
WHY THIS MATTERS: If the piping is smaller than the pump size, fluid will be restricted and negatively affect pump flow, efficiency, and diaphragm life. This step is crucial for long pump life and the most effective operation of the pump.
Filter and Regulate Compressed Air
Perhaps nothing affects the pump’s longevity more than air quality.
Air leaving most compressors is wet, dirty, and often unregulated. The combination of dirty, unregulated air can damage and/or shorten the life of downstream equipment like AODD pumps. Compressed air should be filtered and regulated. Clean, regulated air is the key to trouble-free pump operation.
Air filters/regulators play a crucial role in the performance of AODD pumps, offering protection and precision control by removing solid and liquid contaminants while controlling the air flow. Air filters/regulators provide clean, controlled, consistent air pressure while reducing downtime and maintenance costs.
WHY THIS MATTERS: If you don't use a regulator, you're almost certainly using more air (SCFM) and/or pressure (PSI/BAR) than the pump needs. By not controlling the air volume and pressure, it can cost you efficiency while shortening the life of the pump due to over-pressurization, hard startups, and additional unnecessary pump cycles.
Versamatic: A Vendor You Can Trust
Do you have questions about installing your AODD pump? Put our decades of innovation and engineering expertise to work.
With Versamatic, you get an industry-leading support team that provides guidance on proper pump selection, installation, and operation, and offers troubleshooting tips and maintenance instruction to ensure the safest and most reliable product solution.
Our team of engineers and customer support specialists helps you throughout the process, from selecting the pump to purchasing and providing post-sales support. Trust Versamatic’s experience to understand your specific needs, provide expert guidance, and develop ideal solutions to keep your pumps working at the highest, most efficient level possible.
For more information, please reach out to one of our seasoned application engineers.