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AIR OPERATED DIAPHRAGM PUMPS

Verderair

Air operated diaphragm pumps or pneumatic diaphragm pumps are reciprocating pumps where the working elements are flexible diaphragms. They are a leak-free pumping option offering variable flow and discharge pressures.

Features include:

  • self-priming, dry running
  • rugged construction
  • metallic and non-metallic construction
  • various elastomer options
  • anti-freeze / anti-stall and lube free
  • externally serviceable air distribution systems

WORKING PRINCIPLE

Air operated diaphragm pumps are classified as positive displacement pumps and utilise two flexible diaphragms that reciprocate back and forth. They create a temporary chamber which works to draw in and expel the fluid through the pump. The two diaphragms act as a separation wall between the air and the liquid.

First stroke

The two diaphragms are connected by a shaft through the centre section where the air valve is located. The purpose of this air valve is to direct the compressed air to the back of the first diaphragm, which causes it to move away from the centre section. The second diaphragm is performing suction stroke, and the air behind is being purchased out to the atmosphere.

As this occurs, the suction ball is pushed away off its seat - allowing the fluid to flow past the ball valve into the liquid chamber.

Second stroke

When the first diaphragm has reached the end of its stroke, the movement of the air is switched from the first diaphragm to the back of the second diaphragm by the air valve. The compressed air pushes the second diaphragm away from the centre block, which results in the first diaphragm being pulled toward the centre block. In the second pump chamber the discharge ball is pushed off its seat, whilst in the first pump chamber the opposite occurs. As this stroke us completed, the air valve leads the air again to the back of the first diaphragm and restarts the cycle.

APPLICATIONS

General industry & manufacturing

  • drum and container transfer
  • dosing
  • ink
  • texture Coating
  • paper & pulp
  • general transfer

Water & Wastewater

  • water and dewatering
  • general transfer
  • building services
  • general transfer

Food & Beverage

  • drum and container transfer
  • trade waste
  • sanitary
  • transfer

Chemical

  • acids and chemicals
  • oils and hydrocarbons
  • drum and container transfer
  • dosing
  • acid bath circulation
  • flammable liquid transfer
  • drum transfer
  • CIP chemicals
  • sampling
  • drum cleaning
  • general transfer

Mining

  • acids and chemicals
  • oils and hydrocarbons
  • tanker unloading
  • flammable liquid transfer
  • water and dewatering
  • general transfer

FAQs

How do I read an Air Operated Diaphragm Pump curve?

Global Pumps created a video explaining how to read an determine the values outlined on an AOD pump curve. Watch it here.

Where can these pumps be used?

Air Operated Diaphragm Pumps can be used in a range of applications. They can be used in chemical processing and to pump paint and other viscous liquids. There are hygienic / FDA approved versions for the food and beverage industry and are a great option for dewatering in the mining industry, and can even be used to pump flammable or hazardous liquids.

What are the main features of an AOD pump?

  • They are self-priming
  • They can run dry without damage
  • They are available in different materials for pumping a range of liquids and dangerous chemicals
  • Diaphragm pumps are anti-freezing - meaning they are non-stalling and are lube free
  • Leak free

How many sizes and materials are available?

There are seven sizes available, with a variety of different materials of construction available (including plastics and metals).

How do I know what type of AOD pump to buy?

It is important that you match your requirements to the pump’s characteristics and abilities. Here are five important considerations for choosing an AODD pump:

  1. Fluid: the make-up of your process fluid is crucial to the choice of pump. Does it have special or corrosive requirements? Is it clean or does it contain particles (slurry)?
  2. Viscosity: the viscosity of your process fluid is also important. More viscous fluids require more robust pumps to move them.
  3. Flow rate: you need to know how much liquid you need to move per unit time in order to choose both the correct size pump and the correct size of piping
  4. Pressure: the pressure will also be a major factor, one that intertwined with the flow rate, in choosing an appropriate pump. Refer to your pump’s “pump curve” graph to help determine the relationship between flow and pressure.
  5. Temperature: your choice of pump will need to handle the temperature of the liquid being pumped

What kind of fluid does a diaphragm pump transfer?

Any kind.

Examples include water, acids and lubricants. AODD pumps will handle viscous fluids as long as the viscosity has been taken into account when choosing the pump and designing the system, as some highly viscous fluids require large bore piping to be adequately pumped.

Are there specific considerations for plastic diaphragm pumps?

Because they are plastic, they can change shape slightly over time. As will be seen in the answer to the next question, plastic AODD pumps require more frequent inspection to make sure that the bolts holding the pump casing, haven’t become loose. The only other consideration for a plastic pump is to ensure that the fluid being pumped is compatible with the pump’s plastic/material.

Why do air operated diaphragm pumps freeze?

Although Verderair pumps are anti-freeze, we have created an article here explaining why air operated diaphragm pumps freeze.

What are the key factors for diaphragms pump maintenance?

The good news is that AODD pumps are comparatively easy to maintain. Importantly, and like every other pump, a regularly scheduled maintenance is crucial. You want to monitor things over time, to prevent mishaps before they happen. There are essentially 4 main things to keep an eye on during the life of the pump, these include:

  1. Quality of the air used to operate the pump. Air can come in many different qualities, with various amounts of water. Impurities are removed by an in-line air-filter. Making sure that this is operated and doesn’t become clogged with debris from poor quality air is important to prevent these particles from reaching the pump and causing premature wear on the pump diaphragms.
  2. Examine the pump’s elastomers (diaphragms) routinely for signs of wear - replace these if necessary.
  3. Make sure you frequently check the fluid inlet and outlet of your pump. If either of these become clogged, it can lead to premature failure of the pump.
  4. If the pump is constructed of plastic, which can change shape over time, becoming compressed, make sure that you check the torque settings of the pump’s bolts.

What is the purchase process? How do I find out pricing for an air operated diaphragm pump?

Our Global Pumps team will discuss the application at hand, fluid being pumped and environment the pump is entering. This will provide them with the information they require to offer a quote and outline pricing and other considerations that should be made.

Where do you deliver and what is your estimated shipping times?

Below is a guideline of how long it takes to ship our products to major Australian cities. Of course, we can deliver elsewhere around the county. Our team can advise of specific lead times.
Locations Shipping Time Range
Melbourne 1-2 Days
Sydney 2-3 Days
Brisbane 2-4 Days
Perth 2-4 Days
Adelaide 1 Day
Kalgoorlie 3-5 Days
Mt Isa 3-5 Days

PRODUCT INFORMATION

Global Pumps offer the following Verderair Air Operated Diaphragm Pumps:

Verderair Air Operated Diaphragm - Non-Metallic Series

The Verderair non-metallic series double diaphragm pumps are suitable across multiple industries, including ink and paper, surface finishing, car wash chemicals and water-based paints.

There are four construction materials available in the non-metallic series:

  • polypropylene - wide chemical compatibility, general purpose and limited temperature resistance
  • conductive polypropylene - like standard polypropylene but electrically conductive
  • PVDF - conductive polypropylene and acetal, suitable for use in ATEX rated zones. PVDF is the recommended choice for chemically aggressive media
  • acetal - compatible with many solvent applications and can withstand extreme fatigue. Good resistance to abrasive media and is conductive for ATEX applications.
Verderair Air Operated Diaphragm Pumps - Metallic Series

Global Pumps suggest the metallic series for process fluid that is abrasive. The Verderair metallic series are offered in aluminum, cast iron and SS316.

These Verderair metallic series are commonly utilized in slaughterhouse waste, waste water, chemical transfer, ceramic slurry and solvent-based paints.

There are three construction materials available for the metallic series:

  • aluminium - general purpose, good for solvent-based coatings and inks, resistant to mild chemicals
  • cast iron - highly abrasion resistant, often used in paper, waste water industry and mining
  • stainless steel 316 - resistant to most acids, bases and solvents, can handle halogenated hydrocarbons, good resistance to abrasive media

Air operated diaphragm pumps are controlled by means of compressed air being applied to the air valve incorporated into the pump. The air valves’ unique design guarantees a perfect, non-stalling operation, even at low pressure and does not need any lubrication.

Key features of air operated diaphragm pumps include:
Leak free operation

As AOD pumps do not have plungers or piston rods, leakage could only occur if the diaphragm (or membrane) breaks. Preventative maintenance is necessary to replace the diaphragms and ensure leakage does not occur.

Variable flows

The double diaphragm pump provides variable flow and discharge pressures of up to 870 kPa by simply adjusting the air supply. The compressed air can be used to balance liquid pressure and give high discharge capability. A single air pump can provide a broad spectrum of pumping capabilities from a few litres, up to 1,060 l/min.

Dry-running capabilities

AOD pumps are designed to run dry without damage and are capable of self-priming from a dry start. The air operated diaphragm pumps can also run completely submerged or installed with flooded suction. For ease of maintenance, they don’t require gland packing and there are no close-fitting, sliding or rotating parts to maintain.

Why Air Operated Double Diaphragm pumps?

Backed by extensive research and development, the Verderair® range are the AOD pumps we trust and supply to our customers. Verderair® offer an extensive choice of materials, with the diaphragm series available in both metallic and non-metallic options to suit the application.

They have the capability to transfer even the stickiest of substances, including slurry and solids in addition to standard water like liquids.

We have many varieties of Verderair® AOD pumps that guarantee the safe, efficient and controlled transfer of all types of liquids and chemicals.

Click here to download a free copy of our AODD Cheat Sheet to see which product is right for you, or call on of our specialists on 1300 145 622.

Air operated diaphragm pumps or pneumatic diaphragm pumps are reciprocating pumps where the working elements are flexible diaphragms. The control is by means of compressed air being applied to the Air Valve incorporated into the pump. The air valves’ unique design guarantees a perfect, non-stalling operation, even at low pressure and does not need any lubrication.

Leak free air operated diaphragm pump

Air operated diaphragm pumps are leak free because they don’t have plungers or piston rods which pass through the pressure boundary. A leakage can only occur if the diaphragm, also referred to as the membrane, breaks. In preventive maintenance, or to avoid breakdowns, it is necessary to replace the diaphragms.

Variable flow

The double diaphragm pump will provide variable flow and discharge pressures of up to 870 kPa by simply adjusting the air supply. The compressed air can be used to balance liquid pressure and give high discharge capability. A single air pump can provide a broad spectrum of pumping capabilities from a few litres up to 1,060 l/min.

Dry running capabilities

Air operated double diaphragm pumps have outstanding dry run capabilities. These pumps are designed to run dry indefinitely without damage. The AOD pumps are also self-priming from a dry start. The Air Operated Double Diaphragm pump can also run completely submerged or installed with flooded suction. For ease of maintenance, they don’t require gland packing and there are no close-fitting, sliding or rotating parts to maintain.

Capabilities

As flow and discharge of the air operated diaphragm pump or pneumatic diaphragm pump is infinitely variable (as mentioned above) one pump can be used for an extremely wide range of capabilities. This eliminates the need for costly motor drives and critical calculations.

Why Verderair?

Besides the general advantages of any air operated double diaphragm pumps on the market, Verderair offers many other advantages for users. Having a wide range of proven products for different applications Verderair offers experience. Verder (diaphragm pump-set manufacturers) has over 50 years of experience with applications for the air operated diaphragm pump. This experience comes from both the industrial and sanitary segments.

Stock

Generally, people expect Air Operated Double Diaphragm pumps to be available on a short term. Therefore Verderair works with an efficient stock-management (for both pumps and parts) and flexible production. With this, Verderair offers a real advantage if you need a pump within a short time frame.

Global Pumps supply businesses across all industry sectors with the most advanced diaphragm pumps Australia.

The air operated diaphragm pumps Australia we stock are from the Verderair® range, which uses compressed air that is effectively shifted from one chamber to another by a linking shaft. The simultaneous back and forth motion forces product out of one chamber, while the opposite chamber is being consistently re-filled to create a continuous cycle.

Within the air-operated range, we have products which differ in port size, flow, and pressure. Some of the core features include:

  • Self-priming capabilities
  • Robust construction
  • Anti-freeze/anti-stall and lube free
  • Externally serviceable air distribution systems
  • Non-metallic construction to reduce corrosion, weight and cost
  • Various elastomer options

For more pumping solutions delivered Australia-wide, contact Global Pumps now.

Enquire here for more information or to request a quote: