What is a shut-off valve? Do you currently have car insurance? Insurance is mandatory to drive in Ohio Yes I have insurance. But please show me your best quotes. No, please help me find the best insurance. Question What is a shut-off valve? Answers A device that prevents air from escaping an air brake system The ignition switch An object connected to the spring brake system Explanation Shut-off valves are used in air supply lines to control the passage of air from one trailer to another. The rear shut-off valve should always be closed to prevent air from leaving the braking system.
