In what position should a pneumatic lockout valve be placed to perform a lockout?

The correct position for a pneumatic lockout valve during a lockout procedure is closed. This is because the purpose of a lockout is to ensure that the pneumatic system cannot release any stored energy or operate unexpectedly while maintenance or repair work is being done. By placing the valve in the closed position, you effectively isolate the system from its energy source, thereby preventing any accidental activation of machinery or equipment.

In contrast, if the valve were left open, it would allow air to flow through the system, presenting a risk of unintended operation. A neutral position typically refers to a state where the system is not actively engaged, but it may not be sufficient to fully prevent the release of energy. The activated position would indicate that the system is operational, which is contrary to the objectives of a lockout, which prominently focuses on safety during maintenance work.