2014GB/T 50109-2014 Design code for softening and demineralization of industrial water
2006GB/T 50109-2006 Design code for softening and demineralization of industrial water
1987GBJ 109-1987 Code for design of industrial water softening and desalination
GBJ 109-1987 Code for design of industrial water softening and desalination was changed to GB/T 50109-2006 Design code for softening and demineralization of industrial water.