| When it comes to using positive displacement | | | | opposite directions, causing the vacuum which |
| pumps, you will be required to know a bit about | | | | then traps the air and the liquids, making the |
| these pumps and how they are used. When you | | | | pumps work. |
| know how they work, it will help you to | | | | Then there are also screw pumps but these are |
| understand how they are used in your business or | | | | considered more difficult and more complex in |
| personal uses. | | | | how they work. They will have two screws with |
| There are two main types of positive | | | | opposing threads that work in two different |
| displacement pumps used today: rotary and | | | | directions to cause the motion. Then there are |
| reciprocating. These each have their own function | | | | also moving vane pumps which make up the third |
| that while similar, are still distinct from one another | | | | common type of rotary pump. |
| in a variety of ways. To fully understand this, you | | | | These have has two parts that work in opposite |
| need to take some time with each one to see | | | | directions in order to create the vacuum that is |
| how it works. As the name suggests, rotary | | | | needed to clear the hose or pipe of air and fluids. |
| displacement pumps work with rotation. They will | | | | If you will be using any of these types of rotary |
| use this rotation to create suction or a type of | | | | positive displacement pumps, it's important to |
| vacuum that draws fluid from the hoses. This | | | | know which type you have and to understand the |
| prevents the need of doing this manually which | | | | basics of how it works. |
| often leaves missed fluids in the hoses or the | | | | The next main type of positive displacement |
| pipes. This will ensure a more thorough job is | | | | pumps are reciprocating. Again as the name |
| done with the pump. Some of these pumps even | | | | suggests, these work with a tapered cylinder that |
| have suction pressure control features. | | | | creates suction when the rotors are turned inside |
| Every pump does have its own issues that need | | | | the pipe or hose. This works in a reciprocating |
| to be addressed of course, and the rotary is no | | | | method, creating the vacuum needed. The liquid |
| exception. One problem you may face with this is | | | | and air are pulled into the chamber that is created |
| the clearance that you need for rotary blades to | | | | by the conical shape of the cylinders. This means |
| work properly. If there is too much room | | | | less air or fluid is going to be trapped in the hose |
| between the outside edge of the hose or pipe | | | | or pipe than if using the rotary pumps. |
| and the pump, it can leave room for the air or | | | | You might also hear of this type being called |
| liquid to become trapped inside instead of | | | | "piston pumps" or "diaphragm pumps". These will |
| vacuuming it out. This can also damage the pipe | | | | cause less air or liquid to be caught in the hose or |
| or hose to the point where it is no longer | | | | pipe than when you use rotary pumps which is |
| effective for the job it was intended. This is why | | | | one reason they are sometimes preferred. It all |
| a popular type of rotary pump is that with gears | | | | depends on what you will be using the pump for. |
| that have sprockets to fit into each other and | | | | So choose your positive displacement pump |
| cause the motion of the rotation. They will turn in | | | | carefully. |