What is the function of Blow down valve of a boiler? / » Thermal Engineering 2 solved MCQs / By admin Question: What is the function of Blow down valve of a boiler? A. to remove sludge B. to build sediments C. to remove flue gas D. to remove ash Answer» a. to remove sludge Note: The above multiple-choice question is for all general and Competitive Exams in India.