Category: 

What is a Diaphragm Pump?

Article Details
  • Written By: J. Stanley
  • Edited By: C. Wilborn
  • Last Modified Date: 30 October 2016
  • Copyright Protected:
    2003-2016
    Conjecture Corporation
  • Print this Article
Free Widgets for your Site/Blog
Snake charmers get snakes to “dance” because of the movement of their flute-like instruments, not their music.  more...

December 4 ,  1945 :  The United States Senate approved of US participation in the United Nations.  more...

A diaphragm pump is a positive displacement pump that uses a flexible membrane to pump fluids. The pump uses a series of check valves to ensure that fluid can only travel in one direction through the chamber. The diaphragm itself can be expanded and contracted using pressurized air or fluids, or motors.

Generally speaking, a diaphragm pump moves fluids using a two-part cycle. In the first part, the diaphragm is pulled away from the input/output valves so that the volume of the chamber increases. This increase in volume results in a decrease in pressure within the chamber relative to the input and output, creating a vacuum effect that draws fluid in. Check valves on the input and output connections ensure that fluid can only enter the chamber through the input connection.

After the first phase completes, the membrane in the diaphragm pump is pushed back into the chamber. The volume within the chamber then decreases and the pressure increases. The fluid within the chamber is pushed through the output connection. As with the input cycle, the attached check valves allow fluid to exit the chamber only through the proper connection.

Ad

In most cases, the diaphragm itself is sealed to the sides of the pump, completely separating the chamber from the actuating mechanism. Because the mechanism doesn’t actually move the diaphragm, but rather stretches and contracts it, there is little friction within the pump itself. This feature of the diaphragm pump sets it apart from other types in that it allows the pump to run dry for extended periods of time without incurring damage. This, along with their flexible designs, allows diaphragm pumps to be used in anything from heavy industrial applications to artificial hearts.

There are two primary types of actuators for diaphragm pumps. The first utilizes pressured air or fluid to expand or contract the diaphragm. An increase in the pressure on the actuator side of the pump pushes the diaphragm into the chamber, increasing the pressure on the fluid within the chamber and forcing it through the output. Likewise, a decrease in pressure on the actuator side causes the diaphragm to flex away from the chamber.

The second type of actuator uses a mechanical device attached to the diaphragm to push and pull it into and out of the chamber. The effect within the chamber is identical regardless of the type of actuator used. Only the mechanism used to drive the pulsations of the diaphragm is different.

Ad

You might also Like

Recommended

Discuss this Article

Sinbad
Post 2

@Tomislav - There is most definitely a connection, but the word diaphragm is used in other applications to simply mean a thin sheet of metal or other material that forms a division between parts. But again that resembles what the diaphragm in our bodies does so you are on point with your connection!

Tomislav
Post 1

How brilliant that they used the muscle action of the diaphragm in our bodies to create such as useful product. I had seen these diaphragm pumps in industrial supply store websites but had not made the connection until I was in my biology class discussing the respiratory system.

Am I right in making this connection? Or is diaphragm a more commonly used word for other applications than I am assuming?

Post your comments

Post Anonymously

Login

username
password
forgot password?

Register

username
password
confirm
email