How to correctly install air vents in the steam system
Air vents should be installed at the following locations in the steam system
On steam distribution lines, especially at the end of the steam mains (see illustration below).
Illustration : Installing air vents
Air in steam pipelines gets pushed towards dead ends. This air-steam mixture which makes its way to the process will not be at the same temperature as steam and will reduce heat transfer efficiency of the process.
Illustration: Installing air vents
An automatic airvent evacuates air and non-condensable gases from the steam distribution system eliminating possibilities of air hampering heat transfer.
Air vents should also be installed at the highest point on process equipment or where air is likely to get pushed /trapped as steam enters into the process equipment
Air vents should always be installed above the condensate level so that the air can reach the vent.