Plant Isolation Systems – Lock Out Tag Out
LOTO – Plant and Equipment Isolation
Hazardous Energy Plant Isolation Systems (LOTO – Lock Out and Tag Out) must be effective and efficient to protect employees when working on energised plant and equipment.
Tasks on complex plant may require many items to be mechanically and electrically isolated from energy sources and de-energised.
Determining the correct points to be isolated and constructing the isolation permit requires personnel with significant expertise in plant operations with the ability to read and interpret drawings and determining isolation points in the field.
Organisations operating large and complex plants usually appoint Permit Coordinators, Permit to Work issuers and isolation officers to undertake this disciplined task.
Significant safety (error enforcing) and time absorbing administration issues (Effect on Plant Uptime Availability) are apparent in many LOTO isolation processes such as:
- Lengthy isolation permit processing and authorisation time
- Lengthy time to isolate plant and equipment
- Extensive waiting and queuing time for employees to apply their personal locks to lock boxes and isolation devices
- Inadequate verification of correct isolation points
- P&I Drawings and SL Diagrams are not up to date or do not reflect changes to plant processes
- Isolation procedures are too complex and error enforcing
- Inadequate training in isolation procedures
- Inadequate compliance auditing of the implementation of isolation procedures
- Inadequate review of the effectiveness and efficiency isolation procedures
- Poor labelling of isolation points on drawings and in the field
- Inadequate investigation of isolation incidents
- Poor understanding of stored energy sources such as pressure and hazardous chemicals.
- Poor understanding of what can go wrong at initial plant (first time) energisation and loading.
- Employees finish work, leave the work area and forget to remove their personal isolation lock and tag
Personnel who work and provide advice on isolation systems must be specialists in the area with operational,engineering/trade backgrounds and have extensive experience in the design and implementation of plant isolation systems and be able to:
- Conduct LOTO Procedural Compliance Audits
- Review, assess and customise isolation procedures and determine requirements to reduce administration time and improve the reliability of isolations.
- Develop set piece isolation lists for standard tasks
- Inspection of the accuracy of labelling of isolation points on drawings and in the field – and relabelling as required
- Assess the change control processes for isolation points when plants are modified or upgraded
- Provide training in isolation systems and procedures
- Conduct forensic and detailed investigations of isolation incidents
- Provide advice on commercially available electronic isolation systems
The Immediate Future
Isolation LOTO Processes and associated infrastructure will change as detailed below:
- Paper and hybrid electronic isolation processes will be replaced by paperless electronic “Tap and Go” sign on/lock on and off systems – similar to paying the bill at the supermarket checkout.
- Each isolation action will be digitally recorded – enabling businesses to analyse tasks and to remotely view see Isolation Permit Status in real time.
- Plants will be geo-fenced enabling detection of employees who have left the work area and left their isolation locks and tags in place.
- Energy isolation devices (valves, electrical breakers) will be electronically tagged in addition to alphanumeric labelling – making the verification of plant isolations much easier.
- The location of isolation points will be viewed in a Virtual Reality and Augmented Reality setting – enabling much easier design of Isolation Permits.
