The difference between Diesel portable Screw Air Compressors and diesel piston air compressor in well flushing is mainly in the following aspects: 
1 The working principle is different: the diesel screw air compressor compresses the air through the rotation of two screws, while the diesel piston air compressor compresses the air through the up and down movement of the piston. 
2.Different scope of use: diesel screw air compressor is applicable to large well pads, while diesel piston air compressor is applicable to small well pads. 
3.Different air output: the air output of diesel screw air compressor is large, which can meet the needs of large well pads, while the air output of diesel piston air compressor is relatively small, which is suitable for small well pads. 
4.The difficulty of maintenance is different: the maintenance of diesel screw air compressor is relatively simple, while the maintenance of diesel piston air compressor is relatively complex. 

To sum up, the difference between diesel screw air compressor and diesel piston air compressor in well cleaning mainly lies in working principle, scope of use, air output and maintenance difficulty. It is very important to select appropriate air compressor for well flushing operation according to the actual situation and demand of the well pad.