Lockout/Tagout (LOTO) is the process used to ensure that dangerous equipment is properly shut off and not started back up before the completion of the maintenance work. It requires that the equipment is isolated from any hazardous energy sources and rendered inoperative before any work on the equipment is started. Usually, the device or the energy source is locked with aso that no hazardous energy sources can be turned on. A tag is often placed with the lock, or if locking is not an option hanging a tag is an alternative, hence the name Lockout/Tagout.
The LOTO process is a more complicated precaution for a certain hazard. Typically, the procedure consists of steps to isolate the equipment from its energy sources. Changing out the worn impeller of an acid pump may require several steps. Since the pump must be opened the obvious hazards are kinetic energy (rotating impeller) and the acid itself. Both may cause bodily harm and the acid may also cause an environmental problem.
The LOTO process to isolate the pump from these two energy sources may, for example, consist of these steps:
Switch off the electricity to the motor of the pump and lock the switch. The kinetic energy is not a threat anymore.
Next close the valve on the inlet and on the outlet of the pump.
Lock the valves. You have stopped the flow of the acid, which is a big step towards being safe, but there is still acid inside the pump, so the isolation is not complete yet.
Now open the bleed valve and drain the pump storing the acid temporarily in a container and flush the pump from any acid residue. The acid is not a threat anymore and the pump is isolated and can be repaired.
Before you can define LOTO records you need to define isolation methods and isolation points. Isolation methods are defined on the Tasks screen in HxGN EAM. The Tasks screen is under revision control, but only if you turn on PM revision control (PMRVCTRL).
When PM revision control is active you can bypass the approval list by also turning on PMRVADIR. The new Isolation Points screen is under revision control as well. Revision control is a native function on this screen; it is not necessary to switch on a parameter.