What are the Differences Between a Pump and a Compressor? Pumps vs Compressors (PDF)

Pumps and Compressors are widely used hydraulic machines in chemical, oil & gas, refinery, and petrochemical industries. Both of them even find applications in domestic usage. Both Pumps and Compressors are machines that increase the pressure from the inlet side to the discharge side. Because of this, sometimes the terms “pump” and “compressor” are used interchangeably. But there are some distinct differences between a pump and a compressor. In this article, we will discuss 10 major differences between a Pump and a Compressor.

1. Pump vs Compressor: Flowing Media

Pumps are best suited for incompressible fluids like water, oil, liquids, etc. However, they can operate on gases, or mixed fluid mediums as well. But Compressors operate only for a compressible medium like air, gas, vapor, etc. Compressors reduce the volume of the gas whereas in pumps as it mostly moves incompressible fluid the volume remains unchanged.

2. Pump vs Compressor: Working Principle

A pump forces fluid from one place to another by increasing its pressure. The mechanical energy from the pump engine is transferred kinetic energy to the flowing fluid which subsequently increases the pressure energy. On the other hand, a compressor reduces the volume of gases while increasing the pressure and the mechanical energy is stored in the gas as potential energy.

The main objective of a pump is fluid transfer whereas the main objective of a compressor is fluid compression. As pumps mostly work for liquids there is no density and volume change. But for compressors density increases and volume decreases.

3. Pumps vs Compressors: Storage

Pumps do not have any storage facilities. It only takes the fluid from the suction pipe and discharges it into the outlet pipe. Compressors normally have storage facilities attached to them. So, it can store compressed gases and deliver them when required.

4. Compressors vs Pump: Cost

Pumps are economical whereas Compressors are costlier than pumps.

5. Pump vs Compressor: Cavitation

Cavitation is a characteristic of pumps and can cause pump failure. Compressors do not exhibit a cavitation phenomenon.

6. Pump vs Compressor: Complexity of Design Structure

Industrial Pumps are relatively simple in design as compared to Industrial Compressors. In most cases, Industrial Compressors consume more workspace and are considered more critical as compared to pumps. Compressors have a more vibrating tendency as compared to pumps.

7. Pumps vs Compressors: Temperature Change

During the compression of air or gas in a compressor, heat is generated and the temperature of the flowing media increases as compared to the inlet temperature. But in pumps, such changes are not significant.

8. Compressors vs Pumps: Primary Operating Parameters

A pump is defined by the following basic operating parameters: Flow rate, Head, Specific speed, Efficiency, and Output power. On the other hand, a compressor is defined by Operating Pressure, Flow rate, Compressor power, and Efficiency.

9. Compressors vs Pumps: Primary Components

A pump consists of its casing, impeller, volute, motor, and shaft. Whereas a compressor typically has a motor, storage tank, valves, drains, and intake filters.

10. Pumps vs Compressors: Applications

Domestic Pumps are found in washing machines, cars, ships, airplanes, etc. Industrial pumps are found in every chemical, water, and power industry. They are also used as irrigation pumps, mining pumps, etc. Compressors are often found in the refrigeration and air conditioning industries, processing industries, breweries, refineries, technical gas plants (O₂, N₂ bottles); in pneumatic tools and automatics: shipbuilding, construction, vehicles, etc.