Confined space isolation
For a restricted space entry operation, the restricted space shall be switched to a non-operational state and no hazardous energy or substance shall be allowed to enter the restricted space in any of the following ways:
Install blind plate/blind flange, etc.;
To dismantle or consider a section of pipe or pipeline;
Lock and hang all energy sources;
Truncate or disconnect all connections to a confined space.
Tank isolation (example)