Centrifugal Compressors: Key Performance Evaluation Parameters

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Centrifugal compressors play a vital role in various process applications e.g.

  • Reduction of volume for storage and transport (including LNG/GTL),
  • Natural gas storage in underground reservoir,
  • Chemical reaction taking place at high pressure.
Smooth and trouble-free operation of compressor is absolutely necessary for continuous operation of process plant. Considering this during detailed design stage, evaluation of compressor performance at various operating conditions is an important pre-order activity for Engineering Contractor. This article briefly explains generic boundary limit criteria and preferred operating envelope for Centrifugal compressor performance curve, API 617 Performance Guarantee limits and also throws lights on Impeller performance.


Last Updated on Wednesday, 24 February 2010 20:32

Governor Linkage

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This article is about trouble-shooting the mechanical connection between an Actuator and a Butterfly installed on a Reciprocating (Piston) Gas Engine.
It is based on the use of a Woodward UG8 but generally applies to all mechanical governors used.

Description of the practical problem you're facing

Problem with controlling speed:

  • surging
  • hunting the rods is jigging around
  • always seems to be moving backward and forwards (Control area to fine)
  • trying to control in a few degrees of travel
  • Poor synchronization
Last Updated on Wednesday, 24 February 2010 20:14

Acid contamination of Lubricant causes breaking Piston Rods on a Reciprocating Compressor

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I was asked to visit a chemical manufacturing plant which had three, three cylinder reciprocating compressors installed. The machines had a long history (around twenty years) of intensive maintenance, but periodically a machine would break a piston rod. The machine would then be taken out of service and a standby machine put on line.

Last Updated on Wednesday, 24 February 2010 20:30

Compression Principles & Gas Compressors

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In many industries, compressors are used to add energy to gases in the form of pressure for various uses and processes. Compressors of many, varied types are utilised for this purpose.
In some cases, high pressure is needed in order to liquefy a gas. This is often carried out to greatly decrease the volume of the gas to allow storage and transportation of the liquids to anywhere in the world.
For example, Propane and Butane gases are compressed and cooled until they change to liquid. This is the process used to produce Liquid Petroleum Gas (LPG) which is used commercially and domestically as fuel for a great number of purposes.
Since fairly recently, Natural Gas (Mainly Methane & Ethane) is being liquefied to produce Liquid Natural Gas (LNG). To produce Liquid Natural Gas (LNG), the gas at high pressure is cooled to about - 265°F (-165°C). The liquid can then be stored in special insulated tanks at just above atmospheric pressure. The tankers used for transportation of LNG are also specially built for the job. In liquid form, natural gas can be transported by specially built tankers to countries with little or no natural resources for industrial and domestic use. The liquid is re-vaporised and distributed by pipeline grids to the users. There are a number of types of compressors used for the purpose of

Last Updated on Wednesday, 24 February 2010 20:12
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