Step 3: Isolate

Use energy-isolating devices to properly isolate all of the equipment’s energy sources (secondary sources as well as primary sources). Energy sources include all types: electrical, pneumatic, chemical, hydraulic, mechanical, etc. The sources should be listed and described on the LO/TO program.

Examples of Isolation Procedures

• Electrical: Switch electrical disconnects to the off position. Visually verify that the breaker connections are in the off position. Never just remove a fuse when the equipment can be disconnected completely.
• Hydraulic and Pneumatic: Set the valves in the closed position.
• Chemical: Install blind flange in the system's chemical supply line.