DIFF Subgroup
B08B 9/021 Full Title
Cleaning hollow articles by methods or apparatus specially adapted thereto > Cleaning pipes or tubes or systems of pipes or tubes (apparatus for cleaning metal pipes by chemical methods C23G3/04)
B08B 9/021 Cleaning hollow articles by methods or apparatus specially adapted thereto > Cleaning pipes or tubes or systems of pipes or tubes (apparatus for cleaning metal pipes by chemical methods C23G3/04)