Before work is performed on a valve, fitting, or section of piping in a piping system where employees may be subject to injury from the direct escape of steam, or water, oil, or other medium at a high temperature, the employer shall insure that the following steps are taken:

The isolation and shutoff valves connecting the dead system with the live system or systems shall be secured, blanked, and tagged to indicate that employees are working on the systems. This tag shall not be removed nor the valves unblanked until it is determined that this may be done without creating a hazard to the employees working on the system, or until the work on the system is completed. Where valves are welded instead of bolted at least two isolation and shutoff valves connecting the dead system with the live system or systems shall be secured, locked, and tagged.

Drain connections to the atmosphere on all of the dead interconnecting systems shall be opened for visual observation of drainage.

[67 FR 44545, July 3, 2002]