A Diaphragm Pump is commonly chosen for its robustness, and its ability to easily pump thicker fluids, as well as liquids that contain dirt or waste.
Cotter Marketing Ltd. has been in the business of maintaining, repairing, and improving the efficiency of industrial machinery and components since 1973. We know the products that we work with, and feel the utmost confidence in offering parts and equipment that raise the quality and safety levels of our customers production processes, and reduce their overhead costs from repairs.
Our partnerships with some of the top manufacturers world-wide, such as Samson Pumps, Devcon, Blackmer, and Chesterton, result in relationships that are solution-oriented. We are driven to meet your goals, and are backed by our experience and expertise.
Browse our Pumps and Ancillaries listings. You will find our Diaphragm Pumps in the section below. Most of the diaphragm pumps are AODD pumps (Air Operated Double Diaphragm pumps).
Take a look at our selection of metal and plastic diaphragm pumps. We also offer a number of specialty options. The Cotter Solutions team is ready to help you with advice, ideas, and ultimately, solutions for your industrial processes.
Plastic Pumps
Metal Pumps
FDA and Hygienic Pumps
Speciality Pumps
Benefits of a Partnership Supplier for your pumping solutions
When you partner with the team from Cotter Marketing, your benefits are unlimited
- Our Solutions and Support Teams have seen it all. Our expertise thoroughly covers everything you need to know about our products, including our Diaphragm Pumps.
- We are the sole authorised Irish distributors for a number of world-renowned manufacturers, such as Samson Pumps, Chesterton, Woods Couplings, Blackmer Pumps, and Rhino Valves.
- Our on-site visits ensure that your equipment and operating environments are always kept safe, clean, and in top working order.
- We help prevent down-time with our support, services, and advice
- Our solutions include methodology that works to prevent erosion or abrasion of metal parts.
- We benefit from our partnerships with top quality manufacturers and then pass these benefits on to you, our valued customers.
Diaphragm pumps and their applications
The first air-operated double diaphragm (AODD) pump was introduced in 1955. It was initially used in mining and very heavy construction and needed to be extremely robust for those conditions.
Since that time, AODD pumps have been chosen for industries, such as food, pharmaceutical and chemical, wastewater treatment, and ceramics. These industries take advantage of the pump’s ability to handle fluids with high viscosity.
Advantages of diaphragm pumps
The advantages of diaphragm pumps are unique and should be taken into account in your pumping solution decisions:
- The ability to handle dry periods without incurring damage
- Accurate delivery, even under high pressures
- Strong suction lift
- No need to prime
- Relatively inexpensive because of its simple mechanics
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Our selection of diaphragm pumping solutions is available above. If you need to consult with our Solutions Team, we are always available to discuss your industry, and the pumping products that will suit your requirements.
Pumping systems are not necessarily simple to select. The materials, structure, and specifications of each pump are factors that must match your industry and your goals.
The AODD pumping option
Most of our diaphragm pumps are air-operated double-diaphragm pumps. This means that the tolerance window is somewhat wider than those of other pumping options in terms of wear and tear. Still, your purchasing choices must be carefully considered, and of course, this is where the Cotter Marketing team excels—in providing you with the support and advice you may need.
The following sections are a sampling of the diaphragm pumps that are available from Cotter.
Air-Operated Double Diaphragm pumps
How do the ALL-FLO AODD pumps work?
The ALL-FLO AODD pump is built from the following five main components:
- Diaphragm rod assembly
- Two diaphragms
- Check valves
- Main air valve
- Pilot air valve
The two sides of the pump take turns activating suction mode and discharging mode. Suction mode is activated by the diaphragm moving inward, causing the balls of the check valve to move towards each other, closing the top valve, and opening the bottom valve. Liquids can now enter the opened bottom section of the chamber. Conversely, the opposing diaphragm moves outward, activating the discharge, by moving the balls of the check valves away from each other, thus opening the top valve. The liquids can now exit the chamber. The check valves make sure that the fluids move in the correct direction.
How do the two diaphragms move alternatively inward and outward?
This is where the air operation comes into play. The main air valve directs pressurised air from the pump, onto the diaphragms, moving them from left to right. By moving up and down, the main air valve keeps the air flowing in the pilot air valve, which alternatively applies pressure to the left and right diaphragms.
The A200 two-inch pump—an example of our products
The ALL-FLO A-Series AODD pumps are available in metal or in a variety of plastic materials. The A200 is a two-inch pump, but this pump is also available in a range of sizes from ¼ inch to 3 inches. (The largest size of the plastic A-Series is 2 inches.)
Plastic ALL-FLO A200
We carry the A-Series pumps in either a polypropylene or a PVDF housing. These general purpose pumps are suitable for many chemical-based industries. The PVDF housing provides stronger resistance to acids and bases, and can withstand higher temperatures.
Specifications of the plastic A200:
- Liquid Port Size: 2 inches
- Standard Suction Port: Right
- Standard Discharge Port: Right
- Air Inlet Connection Size: ¾ inch FNPT
- Air Exhaust Connection Size: ¾ inch FNPT
Metal ALL-FLO A200
Available in aluminium, anodised aluminium, or stainless steel, our selection of metal diaphragm pumps from ALL-FLO are suitable for a variety of general purpose applications. The aluminium pumps offer medium-level resistance to corrosion and abrasion, whereas the stainless steel models provide higher resistance to chemicals and abrasive elements.
Specifications of the metal A200
- Air Inlet: ¾ inch FNPT
- Liquid Inlet: 2 inches
- Liquid Discharge: 2 inches
- Max Suction Lift Capability: 24.4 ft-H2O (7.4 m-H2O) Dry, 31.7 ft-H2O (9.7 m-H2O) Wet
- Max Flow Rate: 190 gpm (719 lpm)
- Max Pressure: 120 psi (8.2 bar)
- Max Diameter Solids: ¼ inch (6.4 mm)
Popular configurations of the A-Series
There are a number of popular configurations for the A-Series pumps. Speak to our technical staff about the various options.
Other examples of AODD pumps from Cotter
- The ALL-FLO S-Series AODD pumps are available in metal or in a variety of plastic materials. The S100 is a one-inch pump, but this pump is also available in a ⅜ inch size (plastic only) and a ½ inch size. The ALL-FLO Max-Pass S-Series is the pump you will turn to for handling solids.
- The ALL-FLO D-Series AODD pumps has a size range of ⅜ inch to 2 inches. The pumps are made from plastic or from conductive PTFE materials. The materials have high chemical resistance and the conductive plastic is ideal for fluids that might otherwise present a risk of electrostatic discharge.
Frequently Asked Questions
What is a Diaphragm Pump?
A diaphragm pump is a pump that works reciprocally, using positive displacement as the method for pumping the contents through the pump. The diaphragm pulses back and forth. This allows the pump to pull in and to push out.
Where are diaphragm pumps used?
The particular design and the robust nature of diaphragm pumps make them extremely versatile
- Low pressure pumps for viscous liquids, semi-liquid fluids that contain fine solids, and heavier oils, such as crude oils
- Diaphragm pumps that are made with Teflon, for high pressure industrial applications that require precise processes
- The distilling abilities for many industries, including food processing, pharmaceutics, cleaning products, mining, and oil
- Automotive and aircraft industries
- Pumping of abrasive, acidic, and alkaline fluids
- Textiles, paper, and semiconductors
- Treatment of waste water and sewage, and of course, the pumping of water, which includes transferring, filling, and removal
- Medical applications that require positive displacement pumping, for example, artificial hearts—they work the same way!
Some acids can be moved through the pumps in lower percentages of concentration. It is important to check whether the material casings can handle your required tasks. For example, PVC pumps can be used for hydrochloric or sulphuric acid, as well as sodium hydroxide. You will need stainless steel housing for lithium chlorides.
Can a diaphragm pump run dry?
Yes! And this is an advantage of a diaphragm pump. They can run dry for extended periods, and because of the simple design of the pump, no damage is incurred.
Do you need to prime a diaphragm pump?
No. Priming a pump is typically required when the level of the fluid is lower than the level of a pump that does not perform suctioning. Without priming, slurry or viscous fluids are near-to-impossible to pump, especially if air bubbles enter the pump. This is all irrelevant when using a diaphragm pump. Positive displacement pumps operate with the air and the fluids, in a reciprocal push-and-pull motion.
Let’s talk!
When it comes to pumps, there is a lot to talk about! After considering the design, the advantages, the mechanism, and the housing materials of diaphragm pumps, you may still need to clarify which solution is best for your industry. At Cotter Marketing, our technical experts can help you build your own custom-designed solutions. We are proud of our technical specialists, who can support your needs in other areas, as well. You can contact us with your questions about diaphragm pumps, as well as any enquiries you may have about mechanical seals, couplings, gaskets, non-destructive testing, industrial lubricants, and metal and concrete coating.
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