Do you currently have car insurance? Insurance is mandatory to drive in California Yes I have insurance. But please show me your best quotes. No, please help me find the best insurance. Question When loading compressed gas, the liquid discharge valves should be: Answers Closed. Greased. Opened. Explanation Keep liquid discharge valves on a compressed gas tank closed except when loading and unloading. Take a FREE Practice Test Now This questions appears in the following tests: Arizona HazMat , Nebraska HazMat , New Hampshire HazMat , Idaho Tank ,