AODD Solutions & Centrifugal Pump Problems
CENTRIFUGAL PUMP
A centrifugal pump design is simple, with easy to understand pumping principles. But they are one of the most difficult industrial pumps to choose for an application.
There are many inter-related design and set up variables that must be correctly determined for a specific application in order for a centrifugal to work as designed.
If the pump and process are set up properly, the pump works very well. However, even small changes to process conditions — flow, pressure, fluid viscosity, NPSHa, or particle level — can dramatically reduce the efficiency and reliability of the centrifugal pump. Rarely, if ever, are these pumps rechecked for viability after any process changes.
Centrifugal pumps are often a source of chronic maintenance and reliability problems. They are designed to operate near a single operating point or Best Efficiency Point (BEP). Moving process conditions even 10% from this point can cut the reliability in half and dramatically lower the efficiency.
AIR OPERATED DOUBLE DIAPHRAGM PUMP
Air-operated double diaphragm (AODD) pumps can be a more reliable choice than centrifugal pumps in many situations.
An AODD pump is easier to specify for an application and can run reliably across the entire rated operating range, not just a single Best Efficiency Point.
If any of the applications or conditions outlined below are part of your process, an AODD pump probably should be considered.
These are some common issues or applications where an AODD pump could be a better solution.
- Shear Sensitive / Highly Corrosive Liquids – Pumps tend to shear liquids / highly corrosive liquids – more as speed is increased, and centrifugal pumps are high speed pumps. This makes an AODD pump a better choice to handle shear sensitive / corrosive liquids. Diaphragm pumps operate at lower speeds, are gentler on products, and are usually preferred in these types of applications since liquid gets uplifted and transported without giving it potency.
- Suction Lift Applications – AODD pumps are capable of creating a suction lift. Standard ANSI centrifugal pumps do not create a vacuum and cannot create a suction lift. Diaphragm pumps are the logical choice when a suction lift is required.
- Variations in Flow – Centrifugal pumps do not operate well when being run too far off the middle of the curve. If a lower or higher flow is needed, efficiency is reduced or can result in cavitation damage, shaft deflection, and premature pump failure. An AODD pump is well suited for varying flow.
- Variations in Pressure or Viscosity – AODD pumps have stall capability. If pumping pressure increases in an application, an AODD pump will easily dead head, or stop pumping. Meanwhile a centrifugal pump will continue to build pressure until something fails, the pump is severely damaged, or both. Some liquids can vary in viscosity due to temperature or chemical reaction. A rise in viscosity alter the flow rate, efficiency, and increase pressure. AODD pumps are the right choice for applications with viscosity fluctuations.
- Power Consumption – Centrifugal pumps power ratio is directly proportional to its flow rate and delivery head and specific gravity. Increase in Viscosity of fluid means direct increase in Power consumption. Meanwhile, an AODD pump has no direct impact of viscosity or specific gravity on its power consumption. Only flow rate correction takes place due to change in viscosity.
- Metering – AODD pumps are an ideal choice for metering applications. They deliver measured flow, controlled and altered flow allowing them to easily meet process requirements.
Centrifugal Pump
- Unable to stall or deadhead without damage
- Narrow efficient operating point
- Shaft seal failure (leaking along rotating shaft)
- Rapid impeller wear due to abrasives, corrosives, or cavitation Internal corrosion due to fluid incompatibility
- Overheating due to low flow (critical with magnetic drive)
- Not self-priming (must have a flooded inlet or filled with fluid
- Surge, or random air pockets generated in the line
AODD Pump
- Deadheading without damage or energy use
- Wide reliable pressure and flow operating range without impacting efficiency.
- Zero leakage / spillage. Popularly known as seal less pump or zero leakage pump
- More broad chemical compatibility and/or viscosity range
- Greater flow control without any damage to pump and parts
- Self-priming
- Has less impact of air pockets and surge on its operation
We offer Global Warranty
We offer Global Warranty for our products, 12 months from the date of Invoice or 18 months from the date of Installation whichever is earlier.
We ship oversees and to P.O. boxes
Yes, we’ll ship your package anywhere that can accept deliveries.