What is a discharge tube and why it is used? All Questions › Category: Basic Electrical › What is a discharge tube and why it is used? 0 Vote Up Vote Down chetan_s asked 4 years ago I need short information. 1 Answers 0 Vote Up Vote Down chetan_s answered 4 years ago It is used to remove the excess electrons and leakage current present in the circuit by rubbing it over electrode.