Lockout-Tagout (LOTO): Switching off machines absolutely safely
You efficiently produce using 500 °C hot shears and 2200 to presses. How do you protect your staff members during maintenance works?
An enormous level of energy is used to efficiently produce in production plants. But maintenance works have to be carried out from time to time requiring an absolutely safe switching-off of the plant. If a staff member carrying out works will be exposed to only "residual energies" his very life will be in danger.
MES develops LOTO-Systems for production plants ensuring an absolute safety for the maintenance works under all circumstances. "LO" stands for "Lock out", the safe locking out of energies, and "TO" stands for "Tag out", the marking of current maintenance works.
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Developing procedures for safe maintenance, repairs, servicing and cleaning
Your machine is probably equipped with many safety features such as a lockable main power switch. But are all components of your electrotechnical, hydraulic and pneumatic systems secured? Do heavy machine components slowly drop after the compressor has been switched off? Do your plants contain lyes, acids or other hazardous substances? Does an explosion hazard exist or may cleaning agents trigger chemical reactions?
MES will assist you to systematically record all of the potential hazards and to develop suitable procedures, according to which your staff members or subcontractors will maintain your plants without being exposed to any hazards.
A machine may present hazards even though the machine had been switched off
Thoroughness will ensure safety: Components of a complete LOTO-System
LOTO (Lockout-Tagout) -Systems are designed to prevent personal injuries and property damages using two packages of measures:
- Lockout: clearly visible devices, through which machines are separated from any kind of energy supply.
- Tagout: clear information about the reason and duration of the lockout and blocking
Lockout-Tagout is designed to provide a comprehensive safety concept for the entering and maintenance of plants:
5 basic rules will provide safety for you
- Planning Carefully study the maintenance instructions, inform production
- Securing: Prevention of accidental start-up of plant/machine
- Use adequate work equipment, including personal protective equipment
- Carry out works as planned, do not improvise
- Final control: Functional test, documentation, hand over plant/machine in working condition
LOTO stands for the blocking of energies in:
- electrical systems
- piping systems
- pneumatic systems
- hydraulic systems
- systems containing chemical, mechanical, kinetic energies, heat etc.
...AND for the prevention of an unplanned energy activation
For this purpose, the electrical components used for the shut-off must be positively driven. All circuit breakers used must also be lockable in their separating function.
Development of a LOTO-System
- Define production-, plant areas and machines
- Prepare a draft (e.g. which energy will be blocked where, residual energies, hazards etc.)
- Draft will pass a technical review by means of a checklist (e.g. have all energies been listed up, are the devices lockable)
- Revision of draft
- Practical test
- Devices, such as main switches etc., will be tagged and made lockable
- Signs, markings
- Locking systems
- Final form
- Training of staff members
Preparation of work instructions
- Who does what
- Which tasks are carried out by plant engineering
- What is allowed for production staff
- Who will be instructed when and how
- Who is responsible for the updating of the instructions
- Procedure and realisation
- Personal safety lock
- Sign "Maintenance works"
- Responsibility
- Clear assignment
Work permit
A work permit is required for many dangerous works:
- activities involving fire and explosion risks, hot works
- works posing a danger of falling
- excavation works, earthworks
- works in confined spaces and containers
- dangerous works
- works for subcontractors
Upon signing the work permit, the operator of the plant will hand over the plant to a plant engineer and will simultaneously inform the plant engineer about the condition of the plant.
The plant engineer will carry out specific preparatory and safety measures, in order to prevent all risks of accidents before, during and after his activities. The measures will be discussed with the plant operator and will be documented on the work permit. Check in detail, whether adjacent departments or plants have to be taken into account.
Upon completion of the works, the plant engineer will hand over the plant to the plant operator again and will close the work permit.
This has only been a summary of the key aspects of a LOTO-System. We would be pleased to advise you about how to guarantee a comprehensive safety standard of your production plants.