The slide contains the concept of useful super heating, how actual VCR system differs from the theoretical cycle. Slide mainly contains the concepts of multi stage vapour refrigeration system, concepts of flash gas removal, utility of flash chamber and concept of intercooling (with extrnal water cooled heat exchanger and also with liquid refrigerant in flash tank). It also contains the flash gas removal in addiction to inter-cooling as well as arrangements in cycle and also has been explained with the help of p-h curve.