The pneumatic pump uses to transfer air or gas. It is also known as an air pump. These types of pumps are most widely used in different industrial applications.

## Types of Pneumatic Pumps

### 1) Piston Pneumatic Pump

In this pneumatic pump, the piston is connected to the air motor and moves alternately up and down. Liquid enters the piston through a series of check valves and then drains through the outlet.

Pneumatic piston pumps are those whose ratio is important and can create very high fluid pressure.

The very simple above given piston pump diagram shows the basic concept of a piston pump, which is the relationship between the effective area on the air piston surface and the effective area on the fluid piston.

It also means that if the pump supply pressure is 100 psi, the fluid pressure can reach 300 psi. At 300 psi, the forces on the air and liquid sides are equal, so the pump stops and maintains this pressure in the system until the air or liquid pressure changes (i.e., the personal storage of the system under pressure).

For high pressure pumps, such as grease pumps, this ratio is generally between 50:1 and 100:1, so how can this be achieved by keeping the air motor size low?

There are two points to remember here:

1. What matters is the actual level difference between the piston ends.
2. The relationship between pressure and flow.

#### i) Actual area differences

This is usually influenced by the size of the rod used to connect the two ends of the piston, which generally have different sizes in the bladder than the liquid chamber.

At extremely high pump pressures, the piston axis in the liquid piston is slightly smaller than in the real liquid piston, which reduces the effective piston surface. At the same time, there is a tree large enough on the wind side to provide the necessary force, but no more, to maximize the effective area.

#### ii) Pressure vs flow relationship

When the piston fluid area is smaller than the air piston of the pneumatic pump, the pressure is high, but the flow velocity is low.

Conversely, when the effective piston area of ​​a fluid piston is much larger than that of a pneumatic piston, the pressure is low, but the flow velocity is high.

In fact, for oil and grease pumps, the maximum effective area of ​​the liquid piston will never be larger than the air piston because there is not enough pressure to squeeze the liquid through the tube or tube.

Leaving aside the different pumping technologies, let’s suppose we have two pumps with the same operating principle, the same ratio (same difference in effective area) and the same working pressure range, but the flow rate of one is faster than the other. . This is the only way to cross. Reduce the two larger pistons of the flow model, keeping the same ratio of area difference between the pistons and you can get a higher flow rate.

There are many other ways to improve the performance of a piston pump outside of this topic, but the difference in piston size still determines the ratio and therefore the pressure output potential.

So just to check; For a 1:1 pump, the maximum outlet pressure is theoretically equal to the supply pressure, a 3:1 pump is 3 times the beverage pressure, 5: 1 is 5 times the supply pressure, 50: 1 is 50 bar, and soon.

### 2) Double diaphragm Pump

This pneumatic pump has two chambers on each side of the pump and each chamber has an opening inside. The two diaphragms are actually connected by a rod and between them there is an outlet and air exchange mechanism.

Air is applied to the inner surface of the flexible diaphragm, but only one side of the air is applied at a time, causing reciprocal movement.