A positive displacement pump (PDP) is a pump type that captures a certain fluid amount inside its cavity, and then discharges it. The fluid displacement that occurs is done by a piston, plunger, diaphragm, and so on, depending on the pump type. Some equipment features an expanding capacity at the suction side or/and a reducing capacity at their discharge side. The fluid is brought in as a form of suction via the inlet side as the cavity expands, and is discharged when the cavity reduces.

Types of PDPs

There are two varying types of pumps generally – centrifugal pumps and PDPs. PDPs are a kind of Viking pump that could be further categorized into three varying formats.

  1. Reciprocating.
  2. Rotary.
  3. Linear.

The three categories comprise many pump mechanisms that are implemented by particular industries.

Rotary pump:

  • Screw pump.
  • Gear pump.
  • Rotary vane.

Reciprocating pump:

  • Piston pump.
  • Circumferential piston pump.
  • Plunger pump.
  • Diaphragm pump.

Linear pump:

  • Chain pump.
  • Rope pump.

Defining the rotary type

In this type of pump, the fluid is conveyed with the assistance of a rotary. The rotary’s rotation gets the fluid displaced from the reservoir into the discharging pipe. Some among the most common examples include screw pumps, flexible impellers, helical twisted roots, internal gears, sliding or flexible vanes, circumferential pumps, and so on.

Defining the reciprocating type

This is perhaps the most commonly used of all positive displacement pump types. In the pump type, the reciprocating part, which moves forwards and backwards, helps the liquid that is being conveyed to move forward from the part that functions as the reservoir. The reciprocating component could be a piston, plunger, or diaphragm. This type of pump features several valves including the outlet as well as the inlet ones. During the fluid suction process in which the pump takes the fluid in, the inlets are opened while the outlets are closed. The opposite of this is what occurs during the process of getting the fluid discharged from the valve. As the pump’s piston moves towards the right, its cavity is expanded and the fluid that is to be conveyed is then sucked into the cavity.

Defining the linear type

In this pump type, the fluid’s displacement occurs linearly, which actually means that it takes place in a straight line. Chain pumps, as well as rope pumps, are the basic examples of this type of pump. There is no calibration that is required when it comes to this type of pump. Its model is typically set in a location that is static. Nevertheless, volume happens to be a factor in this type of pump. As a result of the retraction of the piston inside their cavity, linear pumps produce a lot of noise and so, have to be installed far from residential areas.

In concluding, the positive displacement pump features a massive benefit with its wide range of differentiation when it comes to pump types. If you want to understand your individual requirements and get the most appropriate pump for your business, then hire a professional. The experts are always prepared to help you make the most appropriate choices.