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How does a diaphragm pump work?

In today's Rapid Insight, we will review how diaphragm pumps work.  So, how does a diaphragm pump work? 

It all starts with an electric motor used to generate up and down motion, and that's done with what we call an eccentric and a counterweight.

The eccentric is the piece in the middle. It is used to attach the piston with the hole drilled off center - that's why it's called an eccentric.  The amount of eccentricity determines the stroke.

So, what we want to do is we want to turn that up and down motion into a motion of a diaphragm so that we can drive the pump.   The way that's done is you put the piston inside the body, and you connect it to a diaphragm on the top.

So, what happens now is every time this piston goes up and down it drives this diaphragm up and down. That’s why it's called a diaphragm pump, but that's only half the story.

Now, we just got this thing pushing up and down. How does it create flow?

The way it creates flow is with a valve plate, and the valve plate has two valves, one that's pointing in one direction and one that's pointing in the other direction.  Basically, air can flow one way but not through the other and vice versus.

So, you have two one-way valves on opposite sides. What you do now is put that on top of the diaphragm. Now what happens is every time the diaphragm goes up and down, it sucks air in one way and pushes it out the other.

Then, we put a directional head plate on it, and now you can see the air coming in through the intake valve and going out through the output valve. By doing it this way, you can see that diaphragm pumps can be used either for suction by using the inlet or compression using the output.

Thank you for watching today's rapid insight. If you have any further questions, please leave us a comment, and we’d be happy to answer.

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