"Compressors" is used in all aspects of gas industry including gas injection, gas transmission, refrigeration, and distribution systems of domestic gas. Compressors are gas movers where mechanical work is done on the gas resulting in an increased pressure. In gas transmission, two basic types of compressors are used: reciprocating and centrifugal. The reciprocating is well suited for high pressures and low volume flow rates. It can be single or multistage with ratings from fractional to more than 20,000 horsepower per unit. The pressures range from a vacuum at suction to 30,000 psi at discharge. A centrifugal compressor uses the impeller to furnish rotational speed that squeezes the gas outward resulting in some increase in the pressure in the casing using the relationship between velocity and pressure.
Many times we may face to decide whether to use a reciprocating or a centrifugal compressor for driving the gas. There are advantages and disadvantages for either compressors design depending on where the compressor to be installed, the system demand, the gas being transmitted, expansion plans, variable system parameters, initial cost, maintenance issues, reliability, space, power, personnel knowledge and experience with the compressors.
All of these factors will be explained in details comparing between both types of compressors in regards with their operating principle, efficiency, energy consumption, performance which varies with changes in process conditions and maintenance. This comparison has been made to help the concerned people working in this field for taking the proper decision based on the information given in this research.