Pumps are normally used to move fluids from one place to another. They have two different types, namely, hydrodynamic and hydrostatic. Hydrostatic pump is a positive displacement pump while hydrodynamic is a fixed or variable displacement pump. The variable displacement pump gives room for adjustment while a fixed displacement pump cannot make any adjustments.
To get a clear idea of what are positive displacement pumps, below are some positive displacement pump types. These types are classified according to the mechanism they use to move fluids.
- Reciprocating pumps normally use pistons and cylinders. They have a suction which discharges valves into pumps. This pump draws liquid in the cylinder using a suction valve and discharges them under positive pressure using outlet valves. Examples of reciprocating pumps are Diaphragm pumps, plunger pumps, radial piston pump and also piston.
- Linear pumps are another type of positive displacement pumps. These types of pumps are not affected by supply pressure, fluid thickness, fluid or pump pressure and needle size. Some of their features include dispensation of wide pattern range, spiral fills and dots for both filled and unfilled fluids.
- Rotary pumps use rotating vanes, gear or screws that create chambers on each revolution of the drive shaft. Rotating parts and stationery parts are kept clear to reduce any form of slippage. The close clearance of rotary pumps eases operation at a lower speed and gives reliable operation that helps in maintaining pump capacities. Rotary displacement pumps have been grouped into three, namely, screw pumps, moving pane pumps and gear pumps which are similar in operation to a positive displacement oil pump.
Among the list of pumps available, there are also positive displacement hydraulic pumps which have the ability of pushing larger liquids into hydraulic systems.
Some Uses of Pumps
- Domestic pumps are commonly used to supply water in homes.
- Industrial pumps are used as cooling systems, delivering water to industrial companies, facilitating water treatment. They are also helpful when washing using high pressure.
- Trash pumps come in handy when pumping huge amount of liquids for purification. They are essential in our day to day lives and are affordable.
When purchasing a positive displacement pump, you should first identify where you want to use it. Then you can check for the quality of the pumps whether you purchase them online or hardware stores that specialize with these types of pumps. It is always important to ask for advice from your local store as they are best equipped with the information to guide you on the best type of positive displacement pump to purchase.