Contaminants in natural gas streams are generally a mix of solid particles, lubricants from compressors, water and heavy fraction of gas that tend to liquefy.
These contaminants shall be eliminated whenever the gas stream has to undergo a compression or a pressure reduction.
Compressors and pressure regulator operating life is adversely affected by these contaminants so they shall be eliminated as far as possible.
Filter, separators and combined units are used from the upstream gas processing down the line up to the final distribution or industrial use plants.
Different configurations are used along the line of gas transmission and distribution.
In the gas transmission systems KO Drums, separating by gravity, Cyclone separators and Coalescent filters are widely used often in conjunction with Wave Plate elements at the end of the coalescent cartridges. In large industrial users and power plants similar configurations are used as in the gas transmission.
Power plants using gas turbines are generally requiring a higher degree of filtration with 3 micrometres being the standard but sometime reaching the 1 micrometre as well.
In the gas distribution systems city gate station use similar configurations as the gas transmission while along the lower pressure distribution systems dry gas filters are generally used.