YAMADA - High performance diaphragm pump operating principles

An air driven diaphragm pump will start working with compressed air at 1-7 bar.

The compressed air will flow through a valve mechanism to the left or right air chamber.

The two air chambers are separated from the liquid chambers by two flexible diaphragms connected to each other by a centre rod. If the air valve is in a position to allow compressed air to flow into the right air chamber, the left air chamber will exhaust through a muffler. The air flow causes the centre rod to move to the right so the liquid chamber becomes smaller and the liquid is pushed through the valve in the top manifold. The liquid pressure also closes the valve to the right chamber. At the same time the left liquid chamber will get bigger and creates a vacuum so that the bottom valve opens and liquid is pulled into the left chamber.

At the end of the stroke the air valve will switch over and the whole process is reversed.

If the liquid outlet of the pump is closed the pump will stop as the air and liquid pressures will be balanced.

The diaphragm will have balanced air and liquid pressures on each side which gives a long diaphragm life.