Diaphragm Pump Pros and Cons

by Patrick Harmon

Whenever you are moving a material whether it be paint, chemical, or any other substance you may often be evaluating a diaphragm pump as a potential option to transfer material or even to feed a spray gun. Regardless of the specific application, it is good to have a thorough understanding of the pros and cons of diaphragm pumps to understand whether they will work well for your pumping needs.

How Diaphragm pumps work

A diaphragm pump consists of rubber diaphragms that are actuated in an open and closed cycle via a rod that moves the rubber diaphragm. The rod is commonly moved by air or an electric motor. The diaphragm closes the fluid chamber forcing material out of the pump and then the diaphragm direction is switched by the rod movement creating a pulling effect and bringing new material into the pump. This video goes into additional detail on diaphragm pump operations. Having a basic understanding of a diaphragm pumps operation will help understand the pros and cons of diaphragm pumps compared to other pump types.

Diaphragm pump Pros

• Large displacement volume – Diaphragm pumps can move significant volumes of material. For example a standard 2 inch diaphragm pump will usually be able to safely move about 75 Gallons per minute of material.  This makes diaphragm pumps a perfect solution for transferring materials between drums, filling chemical baths, and similar applications.
• Great Wear Resistance – Air operated diaphragm pumps do not have many friction points as the only section of a diaphragm pump to contact material is the diaphragm. Compared to other types of pumps like a piston pump that has a piston moving through a cylinder which can wear over time.
• Variety of Drive Options – Diaphragm pumps can be powered by an electric motor and compressed air making them versatile in application
• Available in Food Grade Designs – If you need equipment to be rated for sanitary applications then a diaphragm pump will be a perfect solution as many are made food grade ready.
• Capable of lifting material – Diaphragm pumps have a lift height rating which references how many vertical feet the pump will draw material up from efficiently. The ability to suction material upward makes a diaphragm pump a great option for moving material out of an area like a well or similar situation.

Diaphragm Pump Cons

• Can be less consistent in fluid delivery during pumping action – One common problem that people mention they have with their diaphragm pump is an issue called a wink. A wink looks like a momentary slowdown or pause in the material being fed and results when the drive shaft switches from pumping on one side of a double diaphragm to pumping on the other side. Winks are usually only an issue when you need a consistent steady material feed, like when used with a spray gun. However, you can often add a back pressure regulator to prevent winks from happening.
• Doesn’t provide high pressure when pumping – High pressure can sometimes be important if you are trying to deliver material over a very long distance or need pressure on your material for another reason.

Common Uses for Diaphragm Pumps

• Material Transfer – Moving paints, chemicals, and fluids between storage containers or storage and working containers
• Feeding Spray Equipment and Spray Lines – If your looking to fed an

   

  air spray

   

  gun a diaphragm pump is a great option
• Material Removal – If you have material stuck in an area and want to move it out a diaphragm pump can be a fast and efficient way to move material out.

Summary

Ultimately diaphragm pumps are versatile and can be used for a variety of applications. By consider the pros and cons of diaphragm pumps you can better decide whether a diaphragm pump will be well suited for your particular application .