Air diaphragm pumps (AOD), also referred to as pneumatic pumps, are a suitable option for a wide range of industries, particularly the food and beverage industry. Their rugged construction, leak-free operation and variable flow and discharge pressures offer operators reliable and safe pumping.
In this blog, our team discusses everything there is to know about selecting a food-grade air diaphragm pump, including top tips to ensure you choose the ideal AOD solution for your delicious product.
What is an air diaphragm pump?
AOD pumps are a reciprocating pump that work using flexible diaphragms. These air 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 separate the air and liquid.
You can watch a video on how an air operated diaphragm pump works here.
What to consider when selecting a food-grade air diaphragm pump
When it comes to choosing your food-grade air diaphragm pump, it is critical you understand what the pump can handle.
Air diaphragm pumps are commonly installed in applications that demand the flexibility to alter flow and discharge pressures. In food or beverage applications, air diaphragm pumps are a popular choice given their ability to handle sticky substances including liquids with solids as well as standard water-like liquids.
To select the appropriate food-grade air diaphragm pump, Global Pumps suggest understanding your product’s characteristics, such as:
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Is your product highly viscous?
Viscosity refers to the fluid’s resistance to flow. Products that are thicker, such as honey or oil, have a greater resistance to flow. In some instances, high temperature or the pumping action, can influence the product’s viscosity - which ultimately influences the integrity of your product. We discuss the importance of understanding viscosity during pump selection in this blog.
Food-grade air diaphragm pumps are a suitable choice for products of high viscosity. Since AOD pumps are a type of positive displacement pump, they can operate at lower speeds and transfer less shear energy to the fluid in comparison to centrifugal-style pumps.
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Does your product change when it is ‘worked’?
Shear sensitivity refers to those products that change when they are ‘worked’. Products like mayonnaise and tomato sauce change in viscosity and become thicker or thinner the more they are pumped.
Food-grade air diaphragm pumps are a common choice when products experience material shear. The gentle pumping action of AOD pumps do not alter the nature or integrity of the product.
- How abrasive is your product?
If your product is abrasive, consideration should be made on the materials of construction for the food-grade air diaphragm pump. If not, the abrasive liquid can cause increased wear to your pump by eroding the surfaces through physical force.
In most instances, stainless steel 316 is recommended for applications that require hygiene or sanitary equipment. Stainless steel can withstand the nature of abrasive material.
- Have you thought about the materials of construction?
Global Pumps recommend a stainless steel construction for your food-grade air diaphragm pump, as they offer operators safe, hygienic transferring and can handle abrasive materials. Besides this, they are capable of withstanding acids, which may be utilised in your clean-in-place (CIP) processes.
If you are looking for a pump to dose or transfer high concentrations of CIP chemicals, we have generated this handy blog that outlines what you should consider.
Different types of food-grade air diaphragm pumps available
There are a wide variety of food-grade diaphragm pumps available and depending on your application there may be more than one option.
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Verderair Air Operated Diaphragm Pump
The Verderair range of food-grade air diaphragm pumps offer operators the flexibility of stainless-steel 316 construction- ideal for applications that demand hygienic practices. Most importantly, the Verderair AOD pump is ideal for fluids that are shear sensitive and/or abrasive - given their rugged construction. The stainless-steel construction is also suitable for those CIP practices - making it a truly universal food-grade air diaphragm pump.
Want to learn more about food-grade air diaphragm pumps? Do you have a few more questions?
Get in touch with Global Pumps! With over forty years’ experience working closely with food and beverage manufacturers, we have a clear understanding of what makes a suitable food-grade air diaphragm pump. Our team works closely with clients to comprehend the application and discuss exactly what is required to meet production demands. Contact us today.
