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Diaphragm Pumps: What You Need To Know

diaphragm pump internal parts diagragm

What is a Diaphragm Pump?

A Diaphragm Pump is a type of positive displacement pump which uses a set of two internal diaphragms either made from PTFE or rubber that work simultaneously to create pressure to push fluid through the pump. As diaphragm pumps are a type of positive displacement pump they are able to self-prime up to 5m from a dry suction pipe or 8m from a wetted pipe.

The Diaphragms also operate the internal valves on the side of the pump which help to control flow direction and fluid quantity being transferred to the discharge outlet. Diaphragm pumps are one of the most common and effective pumps on the market today for companies requiring to move high volumes at a low pressure with their versatility and robustness to withstand a plethora of applications.

 

How Does a Diaphragm Pump Work?

When a Diaphragm Pump is operated, one of the diaphragms creates a 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. Tapflo’s core Diaphragm Pump range is air operated meaning it is powered by a compressed airline. They work in a similar way but with an automatic cycling air valve system behind the diaphragms and feature two ball valves working together to ensure when one is open the other is closed off.

As there are so many variations on the market for Diaphragm pumps, their working principles will all differ slightly. For example, 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 and the application you will be pumping.

What applications are Diaphragm Pumps used for?

Air Operated Diaphragm Pumps can be used for an array of applications and industries. Within our range, we cater for a large variety of applications including our Sanitary Diaphragm Pumps, ATEX rated AODDs, Powder Transfer Pumps and we also have a Low Energy Pump available for those businesses looking to reduce their energy costs and reduce their carbon footprint.

Food & Beverage

The versatility of a Diaphragm Pump means that they are perfect for the Food & Beverage Industry. They can be used in the production of products ranging from dairy products to beer. Pumps are required to ensure the products are made in a sterile and hygienic manner, such as when the environment needs to be kept free from oil contamination. For this industry, Tapflo produces their Sanitary Diaphragm Pumps which are finished to high quality, from hygienic materials with a high grade of finish such as Stainless Steel AISI 316L.

Pulp & Paper

Believe it or not, Diaphragm Pumps can transport glue, adhesives and resin solutions, used in the Pulp & Paper Industry. An example of this is in the production of cigarette paper, where a pump is used to apply the resin to the paper.

Surface Coating

AOD Pumps are also excellent at transporting chemicals, including those used for Surface Coating, from storage tanks, containers and baths. For example, when galvanising and decreasing, such as in the production of linoleum. One example would be Tapflo Group providing a LEAP Pump to a company who were coating urinals. LEAP is a Low Energy Diaphragm Pump that has reduced pulsations, this was perfect for this application at the coating needed to be sprayed evenly.

Water Treatment

Diaphragm Pumps are perfect for handling a range of Waste Water Treatment applications, including transferring water, as well as, dosing acidic and alkali chemicals for treating water.

Print, Paint & Varnish

Tapflo Diaphragm Pumps can also be used for the transfer, recirculation and blending of ink, solvent-based liquids, resins and pigments. Some advantages of using an AOD Pump within this industry include competitive pricing, the ability to handle high viscosities and variable speeds. We have lots of options for this industry, including Mobile Decanting Trollies for large drums, you can check out the full range and a list of benefits in Tapflo’s Guide to Paint Pumps.

Petrochemical

Diaphragm Pumps can be used for offshore Oil drilling in order to carry oil to the surface and to lubricate the drill. Diaphragm Pumps have further application uses in the petrochemical industries such as in offshore mud drilling when rocks are brought to the surface for testing purposes.

Metal Electric Diaphragm Pump

Metal Electric Diaphragm Pump

How does an Electrically Operated Diaphragm Pump work?

Electric Diaphragm Pumps are a great alternative if you want the benefits of a standard Diaphragm pump but don’t have access to compressed air. Tapflo released an electrically operated diaphragm pump back in 2019 that uses the same design effective design principle as their air operated range but modified to create a reciprocating force (left to right) to drive the diaphragms as opposed to rotational.

This was achieved by an eccentric shaft, with a cam and piston which is used to essentially convert the moment from rotary to reciprocating. This force then drives the diaphragms, as usual, using one diaphragm in one of the chambers to create a suction action when being pulled back from the housing. Simultaneously, the diaphragm in the other chamber transmits the pressure to the liquid in the second chamber, pushing it towards the discharge port.

 

Our EODD Pumps are available in hygienic, metal and HDPE/PTFE executions to suit a range of industries. Find out more about Tapflo EODD Pump.

Why Choose Tapflo’s Air-Operated Diaphragm PumpsTapflo Pumps 5 Year Product Guarantee

Tapflo Air Operated Diaphragm Pumps have a compact design and have a simple operating principle whilst still meeting the demands of our customers with heavy industrial applications. Below are some of the main benefits of a Tapflo Diaphragm Pump:

  • Can be run dry without damage
  • Machined from Solid Block HDPE & PTFE
  • FDA/EHEDG Approved
  • 70% less parts than other Diaphragm Pumps on the market
  • No nut, clean face Diaphragms
  • Easy to use, simple design for the operator to take apart if needed
  • No need for guarding device
  • Infinitely variable flow control
  • Fastest Delivery
  • Flexible and easy to adjust
  • Customisable with various diaphragm accessories 
  • Few components
  • Low downtime and maintenance costs
  • 5-year guarantee across the whole range of Tapflo manufactured pump products!  
low energy diaphragm pump range at tapflo

Low Energy Diaphragm Pumps

 

Considerations

  • Compressed air is an expensive way to power a pump, which means that these pumps can be costly to run.

Solution: Low Energy Air Pump and compressed air

  • Air Operated Pumps can be noisy when running at high pressures.
  1. Solution: As LEAP technology can run at a lower flow, using less compressed air so reduces noise pollution.
  • The flow of air from air pumps can be uneven.

Solution: If your application requires a steady flow of air then ask the team about our Active Pulsation Dampener

 

Can a Diaphragm Pump Run Dry?

Diaphragm pumps do have the added benefit of being able to run dry without damage to the pump! However, as a general rule, dry running is usually not recommended for long periods of time as it could cause higher wear to work parts due to there being no fluid within the pump to prime the internals.

To avoid dry running your pump unnecessarily, we recommend using a Guardian System accessory. They are effective at monitoring the fluid discharge pressure of the pump, which stops if the pressure falls below a set point. They are a great alternative to having an operator manually shut off the pump when it’s finished running every time and can also be used for deadhead, stop/restart and barrier protection.

Another way to avoid dry running your pump is to use a level control, which can also be purchased from Tapflo UK and will work with any Diaphragm Pump. The level system monitors the level of media on the suction or discharge and can be set to either a high or low level, which will, in turn, switch the pump off when the levels reach a set point, meaning an all-around easier solution for you!

HDPE diaphragm pump material being machined Material Options

We have a few material options to choose from for your application including 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 balls 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.

What’s the difference between a solid block and a moulded Diaphragm Pump?

Moulding side housings are generally the industry standard within the Diaphragm Pump sector which means that the plastic is melted down and poured into a moulding, this can cause stress to the plastic and can destroy some of its original compounds.

All of Tapflo’s Plastic Diaphragm Pumps are machined from either solid block HDPE or PTFE meaning the original compounds are still intact resulting in much higher resistance to harsh substances like chemicals, making them perfect for use as a Chemical Pump. Tapflo’s AOD design also reduces the risk of leakages compared with a standard

What Types of Diaphragm Pumps are available?

Want to find out more about Tapflo’s Diaphragm Pump Range? Take a look at the video below with Sales Executive Steve at Tapflo UK explaining all about the possibilities of using a diaphragm pump! 

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

Contact the sales team today