A diaphragm pump, also known as a membrane pump, is a positive displacement pump that helps industries standardize on a pump type that works best with a variety of fluids. It only requires a compressed air supply.

Diaphragm pumps are extensively used in construction for configurations of difficult fluids. These pumps can also be specified for ATEX zones, EC1935/2004, FDA, and 3A hygienic applications.

In this blog article, we will discuss the use of diaphragm pumps, their basic components, their working principles, how they work, their applications, and why they are used. Let's explore it!

What Is an Air-Operated Diaphragm Pump?

An air-operated double diaphragm pump, also called an AODD pump, a membrane pump, or a pneumatic diaphragm pump, is a positive displacement pump that uses compressed air as its power source. A connected shaft is used to transfer compressed air from one chamber to another, which allows the chambers to work simultaneously. This movement causes the liquid to flow from one chamber to the discharge pipe while the second chamber remains filled with liquid. 

They belong to "positive displacement" because, at a given pump speed, the flow cannot be maintained if the pump's flow head changes too frequently. Diaphragm pumps can carry low, medium, or high-viscosity liquids and even large solids in the liquid. They can also easily handle corrosive liquids like acid because of their construction using a variety of valve body materials and diaphragms.

Key Components of an AODD Pump

Air Chambers: Two air chambers are used to supply air, one on the right and the other on the left. Compressed air flows through both air chambers.

Fluid Housings: There are two fluid housings as well, one on the left and one on the right, and the fluid is pumped through these housings.

Diaphragm: It is a material that flexes with increasing and decreasing pressure. They have air chambers and fluid housings. A common connector is used to connect both diaphragms.

Inlet manifold: Fluid flows through the inlet manifold to the right or left of the fluid housing.

Air valve: the air valve directs air to the chambers. Through the port, the air valve directs the air to one chamber, while the other chamber has an exhaust port.

Check valves: An air diaphragm has two inlet check valves and two outlet check valves. The check valves control fluid from the fluid housings and manifolds of the pump. Ball-type valves are used in most air diaphragm pumps.

How an AODD Pump Works: Step by Step

1. Compressed air enters the right air chamber, flexing the right diaphragm outward.
2. Pressure builds in the right fluid housing: the right inlet check valve closes and the right outlet valve opens, pushing fluid out through the discharge manifold.
3. Because the diaphragms share a connecting shaft, the left diaphragm is pulled inward at the same time, creating a vacuum in the left fluid housing.
4. The left inlet valve opens and the left outlet valve closes, drawing fresh fluid into the left housing.
5. At the end of the stroke, the air valve switches direction — compressed air now flows into the left chamber instead.
6. The cycle reverses: the left diaphragm pushes fluid out through discharge, while the right diaphragm is pulled inward to draw in the next intake of fluid.
7. This alternation repeats continuously, giving a near-constant flow with no motor and no dynamic seal to wear out.

You may also read:

1. Navigating Reactive Maintenance: A Deep Dive into Strategies and Best Practices
2. Demystifying Partial Discharge: Understanding Its Impact and Detection
3. Exploring Technomax’s Ferrography Services 

Why Use a Diaphragm Pump?

AODD pumps are versatile and provide a diversity of capabilities that allow industries to standardize on a single pump to handle a variety of fluids. The supply of compressed air ensures you can install pumps wherever you want. If the circumstances change, you can easily move it and use it for other operations. Diaphragm pumps are portable, which further makes it viable to use them whenever and wherever you need them.

For fluids that require gentle pumping action because of their chemically or physically aggressive nature, AODD pumps positive displacement, providing an efficient and low-maintenance solution. Once pumps are installed and connected to compressed air, they can function at full autonomy.

The ecological design of AODD pumps saves up to 60% of air. It decreases impacts on the environment significantly. Less air consumption also means a smaller air compressor, leading to savings on energy and costs. Their static seals ensure longevity, resulting in very low maintenance. Maintenance of these seals is also inexpensive.

Lets hover over the benefits of Double diaphragm pumps, also known as Air Operated Double Diaphragm pumps (AODD):

• Portable — powered by compressed air, so they can be relocated wherever an air line reaches
• Gentle on product — low shear action suits fluids that can't tolerate agitation or frothing
• Low maintenance — static seals mean little upkeep, and what maintenance is needed is inexpensive
• Efficient by design — modern AODD pumps can cut air consumption by up to 60% versus older designs, which also means a smaller (cheaper) air compressor to run them

For the full list of AODD pump benefits — dry-run capability, certifications, deadhead safety, and more see our diaphragm pumps overview.)

Applications Of Air Diaphragm Pumps

AODD pumps are used in oil and gas for settling pond transfer, filter press, and bulk fuel transfer.

In pulp and paper, they are used in printing inks, glues, and bulk adhesive transfers.

AODD pumps are used in water and wastewater treatment for transferring suspended solid media in filter presses and utility pumps.

In mining, the use of AODD pumps is extensive for transferring fuel for vehicles or heavy construction equipment, transferring slurries and sludge, and dewatering above and below ground at sites and quarries.

In the ceramic industry, they are used in ceramic slips, day tank transfers, and filling moulds.

In electroplating and anodizing, AODD pumps are used for mixing cleaning solutions, filtration, and replenishing chemicals in plating or metal finishing tanks.

There are wider uses for these pumps in chemical processing in portable utility pumps, for batching or dosing chemicals, and for loading and unloading tankers.

These lists of extensive uses of AODD pumps in different industries show how they are widely used across varied industries.

 Conclusion 

Air-operated double diaphragm (AODD) pumps are highly regarded for their robustness, reliability, and cost-effectiveness. As a result, they are extensively utilized across diverse industries. Their ease of maintenance and low operating costs make them a popular choice for fluid transfer applications. These pumps operate by means of compressed air, which drives the diaphragms to create suction and discharge pressure. The simple design of AODD pumps makes them easy to install, operate, and maintain. Furthermore, their versatility and adaptability to various types of fluids, including abrasive and viscous materials, make them a preferred pumping solution for many applications.

Key takeaways are:

• Many viscous liquids work well with air diaphragm pumps.
• They find applications in several industries, such as chemical processing, mining, and electroplating.
• Due to their safe discharges, variable discharges, and several customization options, AODD pumps are remarkably simple to assemble.
• Maintaining AODD pumps is hassle-free and does not require any concerns about potential leakages.
• The environmental impact decreases considerably as they consume 60% less air.

Looking to specify a diaphragm pump for your application? talk to our team about Yamada AODD pumps.