How to Select a Diaphragm Pump

What is a Diaphragm Pump?

Diaphragm Pumps, one of the most commonly used pump types on the market today, are Positive Displacement Pumps that use two sets of internal diaphragms, constructed from PTFE or rubber, that work simultaneously to create pressure to push fluid through the pump.

Advantages of Diaphragm Pumps:

All Tapflo Diaphragm Pumps use no-nut, clean-face diaphragms to ensure that no liquid can penetrate the diaphragm and are built with 70% fewer parts than other AODs on the market today. Some key benefits of using Diaphragm Pumps are:

• Self-priming capabilities, eliminating the need for external priming
• Handles corrosive, abrasive, viscous, and shear-sensitive materials
• No seals or glands, reducing the risk of wear and tear on common working components
• Can operate under dry-run conditions without damage
• Handles fluids containing solids or particles
• Bi-directional operation
• Steady and pulse-free flow
• Safe for hygienic applications
• Leak-free operation
• Explosion-proof options
• Air-driven and electrically driven options available
• CIP and SIP executions available

Common industries & applications:

• Chemical
• Surface Treatment
• Water Treatment
• Pulp & Paper
• Hygienic
• Food & Beverage
• Mechanical
• Print, Paint & Varnish

What are your fluid & media transfer characteristics?

To choose the appropriate Diaphragm Pump for your application, ask yourself the following questions:

1. What media will be pumped? Consider the chemical composition of the media you will be pumping – is it chemically neutral or corrosive, shear sensitive etc.
2. What is the viscosity of the media you intend to pump? Consider viscosity limitations, shear sensitivity etc.
3. Do you need to pump fluids containing solids?
4. Is your environment or fluid explosive?
5. Do you require self-priming?
6. Do you require CIP/SIP?

Materials Available:

• HDPE and PTFE: HDPE offers a superior wear resistance which is 6 – 7 times stronger than polypropylene (PP), offering greater mechanical strength. Polypropylene is a standard material used by most Diaphragm Pump manufacturers and often weakens over time when used with aggressive applications, which is why Tapflo offer HDPE. PTFE is a thermoplastic polymer which can handle the most aggressive chemicals, with a max liquid temperature of 100°C.

• Aluminium, Cast Iron, Stainless Steel: Our metals are best for viscous, chemically aggressive fluids & fluids containing coarse solids.
• Sanitary: Our sanitary range offers FDA and EHEDG-approved materials suitable for all fluids that are meant for consumption and cosmetics.

Some of our materials offer an ATEX option on request for explosive applications and environments.

Maintenance required to keep your Diaphragm Pumps running:

• Conduct routine visual inspections of the pump’s components
• Check and tighten the pump’s main nuts and bolts to the specified torque settings
• Monitor and clean/replace the air filter regularly
• Keep the air exhaust muffler clear of any obstructions
• Inspect diaphragms for signs of wear
• Check valve balls and seats for wear or damage and replace any worn/broken components
• Regularly inspect suction and discharge pipework for blockages or leaks
• Routinely monitor suction and discharge pressure gauges to ensure the system pressure remains within the working parameters of the pump
• Consider maintenance intervals

Depending on the size of your pump and the fluid you are pumping, a more detailed maintenance schedule may be required.

Additional Factors to Consider:

Will your pump be stationary, or do you need it to be portable? If you require portability, Diaphragm Pumps can be fitted to trolleys of any size to suit your needs.

Will you require additional accessories for your pump? Diaphragm rupture protection, level controllers, pulsation dampeners, and many other accessories to improve the performance of your pump even further are available.