Many facilities shut down their air installation overnight or over the weekend to save air losses caused by leaks in the air main. This method may help, but it has one important disadvantage; very often the complete air main empties during the shutdown period. When the compressors are started again, they have to charge an empty air main, which means that the air treatment systems are sometimes subjected to ten times the normal loading. The result of this overloading is often contamination of the air main, despite good drying and filter systems.
These undesirable effects can be avoided at low cost and installation effort by Kaeser’s air main charging valve. This valve acts as a pressure retention valve and is fitted just downstream of the treatment equipment, allowing fast pressure build-up when the compressor packages are started again. The valve first opens to charge the air main when the working pressure of the dryer or filters has been reached and holds this pressure constant. The air main charging valve not only saves energy, but also plays an important role in ensuring the quality of the compressed air produced by the compressor. | 
