What is the correct position of the shut-off valves for the first trailer of a doubles or triples set?
A. Fully closed
B. Fully open
C. Partially closed
D. Emergency shut-off valve closed; service shut-off valve open
The correct answer is: Fully open. Shut-off valves (sometimes referred to as cut-out cocks) are located at the back of trailers used to tow other trailers. All valves
should be in the open position except on the last trailer which should be in the closed position.