Speak to our Experts: 02380 252 325

02380 252 325

Brochures & Manuals
Pump Support

Tips for Choosing the Right Diaphragm Pump

Here at Tapflo, we have a large range of Diaphragm Pumps to handle any application so we know how overwhelming it can be to figure out which you need. The majority of our range featured air operated Diaphragm Pumps but we also released an Electric Operated Diaphragm Pump in late 2019. We’re here to run you through some of the questions you may be having about your options when choosing your next Air Pump, so sit back as we try to make the process as easy as possible for you.

HDPE/PTFE Diaphragm Pump

Why choose a Diaphragm Pump?

An Air Operated Diaphragm Pump is the best solution for any application where you are required to move high volumes at a low pressure. Diaphragm Pumps have become a popular choice of pump for many businesses for a few very important reasons, one of which is the reduced risk of air contamination. An Air Pump is powered by exactly that, air, some Diaphragm Pumps are also electrically driven, this means that oil isn’t necessary within your pump which could potentially be harmful to your pumping process by contaminating the pump’s surrounding environment or even your product! Diaphragm Pumps are a type of Positive Displacement Pump that use pressure created by the diaphragms to operate the valves, opening and closing them to allow fluid to move through the pump. AOD Pumps are robust due to the diaphragms within the pump being made from PTFE rather than a piston and cylinder system which will cause wear to the internals of your pump.

Diaphragm Pump Applications

  • Food – milk, mayonnaise, tomato products
  • Beverage – beer, wort, fruit juice
  • Chemical – acids, solvent, emulsions
  • Print & Paint – glue, adhesives
  • Cosmetics – shampoo, toothpaste

Visit the Diaphragm Pump product pages for a full list of applications for each range.

How does an Air Operated Diaphragm Pump work?

We talk a lot about the benefits of using a Diaphragm Pump and how easy they are for anyone to use, even without technical training, so let’s take a quick look at the way these pumps operate. The compressed air line in a Diaphragm Pump operates the pump by moving the two diaphragms side to side simultaneously. As one diaphragm creates suction to draw a set amount of fluid into one side of the pump, the other diaphragm will drive the same volume of liquid through the outlet port from the other side of the pump. There are two ball valves on each side of the pump, operating together when one is open, the other is closed, as shown in this diagram.

This should give you a basic understanding of how the pump operates in order to move product through the pump. Due to the positive nature of an AOD Pump, they are extremely versatile. To ensure you choose the right Diaphragm Pump for the job, we’re going to run you through some of the technical details that need to be taken into account.

How Does a Diaphragm Pump work?

Volume Needs of an Air-Operated Diaphragm Pump

The first factor you should consider is the volume of material you’ll need to move. Air Pumps come in an array of sizes so it’s likely that we’ve got something to fit your needs. There are Diaphragm Pumps that can move about a gallon of material per minute – and then there are those that can move hundreds of gallons in a minute. It all depends on the size of the pump and how fast it works. It is also important to note that your required volume will affect the speed at which the pump can operate. The amount of space in the pump head affects how fast material can be pumped through, so you’ll need to get a bigger pump if you want it to move more material, or to move material faster. You’ll want to choose a pump that runs at about half of its maximum capacity during ordinary use. This way, the pump will last a long time with minimal wear to the pump’s internals, therefore requiring less maintenance. If your pump is always running at close to 100 per cent capacity, you’ll need to buy a replacement sooner. You can easily find out the capacity of a pump before you buy – just check the product pages for more information or ask a member of the Sales Team.

To find out more about maintaining your Diaphragm Pump, head over to our ‘How To’ guide

Drive Type

You should also think about the type of drive behind the diaphragms. As we mentioned before, there are 2 types of drive options available with Diaphragm Pumps, electrically driven and Air-Operated Diaphragm Pumps The drive can affect where you can use the pump and how safely you can operate it. For example, if you choose electrically driven pumps, they’ll work anywhere electricity is available. However, in areas where flammable material is nearby, they aren’t a safe choice. This is an advantage of using an Air Operated Diaphragm Pump, particularly as Tapflo can supply these as ATEX rated. An air-driven pump can be used anywhere, as long as compressed air is available. You can use air-driven pumps around flammable and toxic materials without concern because the air can’t ignite anything.


One of the obvious differences in our Diaphragm Pump range is the material your pump can be manufactured from. We have a few options such as Metal, PTFE or HDPE. There are usually a couple of different materials in a Diaphragm Pump: one used to make the ball and seat, and one to make the body of the pump. For example, you may see ball and seats made of Stainless Steel and diaphragms made from PTFE. The material you should choose depends on your needs; Stainless Steel costs more but resists wear for longer and is heat-resistant, whereas PTFE materials cost less but don’t stand up as well to abrasion. For Sanitary applications, such as the Food, Beverage, Pharmaceutical or Cosmetics Industries, a high grade of Stainless Steel is required; all of Tapflo’s Sanitary Diaphragm Pump range is manufactured from high-grade Stainless Steel and ensure optimal hygiene, visit the product pages for more information.

Performance Curve

All of our pumps come with a performance curve which can give you a lot of helpful information. For example, the performance curve of an Air Operated Diaphragm Pump will tell you the volume of air that the pump needs at multiple levels of operation, it will also show you how much material can be moved at each operating level and how far it can be taken. You’ll need to pay particular attention to the amount of air that you’ll need to provide for the pump, to move as much material as you need it to. Keep in mind that you’ll be aiming to operate the pump at about 50% capacity most of the time. The curve will show you higher operating rates, but you don’t want to always operate your pump at the highest rate.

Buying an Air Operated Diaphragm Pump on a budget

We all know that sticking to the budget set from above can prove tricky sometimes so don’t waste money buying the wrong pumps, only to have to replace them later on. A little bit of knowledge goes a long way toward choosing the best Diaphragm Pump for the job. That’s why Tapflo should be your number one choice for AOD Pumps, we’re ready to share our expert pump knowledge with you and we can provide quality Diaphragm Pumps at a competitive price. Our Diaphragm Pumps have long lives when maintained properly which means you won’t spend lots of money on spares or time with your pump out of action. Don’t believe us? Check out the video of our Sales Executive below, he’s got a pump that was installed 11 years ago!

We can also save your company money in the long-term. Tapflo UK has developed revolutionary Diaphragm Pump technology called LEAP – Low Energy Air Pump – this is installed in Tapflo’s TC range of Diaphragm Pumps and is sold globally through the Tapflo network. This revolutionary technology could save your company up to 70% in energy savings by reducing the amount of compressed air used to operate the pump but don’t just take our word for it, check out this case study – LEAP beats leading American Diaphragm Pump!

Electric Diaphragm Pump

In 2019, Tapflo released their Electrically Operated Diaphragm Pump. Benefits of this pump include being able to dry run without damage to the pump and low spares costs. The pump is available, like all our Tapflo Diaphragm Pumps, as HDPE/PTFE, Metal and Sanitary.

Why choose an Electric Diaphragm Pump over an Air-Operated Diaphragm Pump?

  • If you want the benefits of an AOD but don’t have access to compressed air.
  • If you’re looking for more accurate flow control an electrical inverter can be used with the EODD Pump.

Ready to buy a Diaphragm Pump?

Diaphragm Pumps are a great way to get the job done without contributing to pollution and when you choose the best pump for the job, you won’t need to worry as much about maintenance or replacements. With the factors that we’ve shared above, you’ll easily be able to select the right pumps for any application, if you’re still not sure, that’s no problem, our friendly team are on hand to advise you on the best pump for the job!

Want to know more? Contact the sales team for additional support with your application or pump requirements

Contact the sales team today