TRF LIMITED ( BMHE DIVISION) / OCP0024 / 00
Original Issue Date: / Date of Revision : / Page 1 followed by 2
Prepared by: Sudhir Kumar / Approved by: / Issued By:
Title: POSITIVE ISOLATION PROCEDURE
Positive Isolation Procedure
1.0) Policy:--
1.1) To properly apply this procedure in all circumstances, one must understand the intent of the procedure, which is to ensure the safety of personnel who will be performing the work. Operating and maintenance work shall be done without injury to personnel, Equipment or causing environmental damage.
1.2) Personnel using this procedure must assume responsibility for their individual safety and that of fellow employees and always remember that doing the job in a safe manner is more important than such things as saving time, avoiding effort, increasing convenience or increasing production.
2.0) Scope:
This document specifies the methods and procedures for the positive locking system. This procedure covers only positive Isolation for the Energy Sources. Other procedures like Working at height, working in confined spaces, welding and cutting jobs, Gas safety etc are not in the scope of this procedure and shall be followed as per the existing norms. The Positive Isolation is over and above the existing safe practices so in all the cases the existing practice of taking Work Permit shall continue.
3.0) Exemptions:-- At present the Electrical jobs like, all the jobs below and up to 250V AC and 220V DC, Lighting circuit, Electrical maintenance jobs in buildings; such as jobs on tube lights, fans, PCs etc shall not be covered under this procedure. However, all the existing systems of taking the Work permit shall continue. It is clarified that those electrical equipment which are controlling/regulating other energy sources shall be included in this. There is no exemption for other energy sources except for the Electrical energy as mentioned above.
4.0) Definitions:
· Complex Isolation: Complex Isolation is when more than three Isolators or more than two Energy Sources are involved. All complex Isolation shall have a written procedure.
· Control Stop: Control Stop is a method of stopping Equipment (where Isolation is not used) for the performance of high frequency, short duration, and low risk routine tasks. A separate Control Stop procedure is to be developed. Control Stop procedure shall not be used for High voltage system.
TRF LIMITED ( BMHE DIVISION) / OCP00 / 00
Original Issue Date: / Date of Revision : / Page 2 followed by 3
Prepared by: Sudhir Kumar / Approved by: / Issued By:
Title: POSITIVE ISOLATION PROCEDURE
· Energy Source: Any source of electrical, mechanical, hydraulic, pneumatic, chemical, thermal, radioactive or other energy.
· Energised: Equipment connected to an Energy Source or containing process material or stored energy.
· Equipment: All process machines and service systems including units such as pumps, compressors, and piping systems such as refrigeration Equipment, heating and ventilation systems, lighting, tools, instrumentation and circuit breakers etc.
· Equipment Lock: Shut Down paper will be pasted on equipment/power source & main switch handle with fuse will be removed by an Isolating Person to an Isolator in the safe position to prevent accidental or inadvertent movement
· Group Isolation: This is a preferred system of Isolation when a number of people are involved and/or a number of Isolators handles & fused are to be removed.
· High voltage: A voltage exceeding 650V (This does not include 650V) under normal conditions however the percentage variation as per IE rules is allowed.
· Isolator: A device which positively separates or blocks the Energy Sources to Equipment, the device is not capable of remote operation whilst in the Isolation position. Devices such as push buttons, emergency stops, Limit switches, and rail wedges are not Isolators.
· Isolating Device: A mechanical device that physically prevents the transmission or release of energy. The following are examples but not exhaustive, of an Isolating Device: - Circuit breaker, Line valve etc. The term does not include; a local start/stop switch, selector switch, Automatic valve, Interlocks, overrides etc. A slip blind or end blind used for the purpose of Isolation physical disconnects, example: Disconnecting of tubing’s, removing of spool-pieces or flexible hoses.
· Isolation: Separating or blocking the energy and removal of residual energy beyond the energy block, and control measures taken to prevent unauthorized removal of the energy block.
TRF LIMITED ( BMHE DIVISION) / OCP00 / 00
Original Issue Date: / Date of Revision : / Page 3 followed by 4
Prepared by: Sudhir Kumar / Approved by: / Issued By:
Title: POSITIVE ISOLATION PROCEDURE
· Isolating Agency: A department or unit which is authorized to execute Isolation of the Equipment such as particular section Mechanical /Electrical.
· Isolation Boundaries: This describes the extent or coverage of the Isolation where people are protected by their Personal Locks.
· Isolating Person: A person who performs Isolation and who is Authorised under this Procedure. Each Department shall identify the Accredited/Authorised Persons for every type of job. Only these persons shall be Authorised to issue the shut down acceptance for doing the job. These persons shall be defined as Isolating Persons.
· Isolation Planners: These persons shall be normally senior persons of the Department/section. Isolation planners shall be responsible for preparing and maintaining the Isolation procedure for the Isolation.
· Isolation Procedure: A document which defines what Equipment is to be isolated and how the Isolation shall be done. This document is used when the Isolation is being performed.
· Isolation Training Level 1: A training course for Protected Persons.
· Isolation Training Level 1A: A training course for Isolating Person. This covers the contents of Level-1 and some more topics required for giving the isolation.
· Isolation Training Level 2: A training course for Isolation Planners. This covers the contents of Level-1A and some more topics required for preparing and maintaining the isolation procedure.
· Lock Out Point: Valves, Switches, controls, breakers, or other devices which, if operated would activate the Equipment and potentially result in injury or Equipment damage.
· Lifting the Isolation: The returning of Isolators back to their operative positions i.e The reversal of Isolation.
· Multi-Lock Device: A device which can secure an Isolator in safe (Isolated) position and can be secured by a number of shut downs / locks.
· Protected Person: Those who will attach their Personal Lock to an Isolator or a Group Isolation Box for TRF Employees or those Contractor’s workers on whose behalf their supervisor has placed the lock along with the list of workers.
TRF LIMITED ( BMHE DIVISION) / OCP00 / 00
Original Issue Date: / Date of Revision : / Page 4 followed by 5
Prepared by: Sudhir Kumar / Approved by: / Issued By:
Title: POSITIVE ISOLATION PROCEDURE
5.0) Methods of Isolation:
5.1) General: There are four methods of Isolation
a) Control Stop---- Isolation;
b) Individual ---- Isolator Isolation;
c) Isolation for working alone, however which methods of isolation are to be used for particular job shall be decided by the owner of the energy source.
5.2) Control Stop:
5.2.1) Control Stop is a method of stopping Equipment (where Isolation is not used) for the performance of short duration, low risk routine tasks. A separate Control Stop procedure is to be developed. Control Stop procedure shall not be used for High voltage system IN ANY CASE.
5.2.2) Where Control Stop can be used: Control stop system shall be applied to routine tasks where full isolation of energy is impractical to implement. It should meet all of the following criteria:
· Routine Task
· Short duration task i.e. < or = 30 Minutes
· Low level of Consequences i.e. Even if isolation fails it should be restricted to minor injury.
· Control Stop Procedure should be approved by Head of Maintenance.
· The Operator and working agency should be trained on Control Stop procedure.
5.2.3) Where Control Stop can NOT be used: Control Stop System shall not be applied to nor exemptions granted for the following job which are:
· Non Routine job
· Involve Electrical work on equipment or near bare conductors
· Involve specialist isolation like High voltage or Combustion
TRF LIMITED ( BMHE DIVISION) / OCP00 / 00
Original Issue Date: / Date of Revision : / Page 5 followed by 6
Prepared by: Sudhir Kumar / Approved by: / Issued By:
Title: POSITIVE ISOLATION PROCEDURE
5.2.4) Control Stop Indication:
· When control stop is selected and successfully executed then a green control stop light should illuminate. The light shall be located at the top of the control cubicle for maximum visibility.
· When control stop is not selected and normal line run conditions exist, a red normal light shall glow at the control stop switch
· Control stop switch shall be assumed unsuccessful if the green colour control stop light does not illuminate.
5.2.5) How to achieve control stop:
· Control stop switch shall have only two position
· Multiple combination switches shall not be used.
· The interlock shall be hard wired. PLC Logic is not permitted.
5.2.6) The Head of Maintenance should also define authorization for different Control Stop jobs and only authorized persons can carry out Control stop.
5.2.7) Procedure for the Control Stop:
· The agency which wants Control Stop shall request the Isolating Agency (Electrical/Mechanical/Operation etc) for Control Stop and indicate the details of the job for which the Isolation is being demanded.
· Control Isolation shall be given by the authorized persons to only those agencies/ individuals who demands for it. This is to restrict the system only to those who are knowledgeable enough and regular worker / supervisors of that plant.
· The Isolating Agency shall confirm whether the job described qualifies for the Control Stop or not.
· After confirming the above, the Isolating Agency shall execute the Control Stop as per the standard Procedure and give the clearance for doing the jobs.
TRF LIMITED ( BMHE DIVISION) / OCP00 / 00
Original Issue Date: / Date of Revision : / Page 6 followed by 7
Prepared by: Sudhir Kumar / Approved by: / Issued By:
Title: POSITIVE ISOLATION PROCEDURE
· When job is finished then the working agency shall remove all the personnel from the site and give the clearance to the Isolating agency for lifting the Control Stop.
· After Lifting the Isolation, Isolating Agency shall inform back to the owner/operation for its availability.
Note:
Procedure for the various communications involved in the above process are to be finalised by departments so that any possibility of communication gap is avoided .
5.3) Individual Isolator Isolation:
5.3.1) General :This procedure is to be used preferably :-
a) when Isolation is to be done at a single place and
b) The agencies involved are not more than two.
c) The agencies asking for Isolation may be allowed to enter the area for applying the Locks & shut down handing over, without any risk to the plant, machinery, safety of person as well as Equipment and mal-operation. If any one of the above conditions are not met then Isolation method is to be adopted.
5.3.2) Work flow for the Individual Isolator Isolation:
· The agency which wants Isolation shall make a request in writing identifying, the Isolating Agency (Electrical/Mechanical etc) for Isolation and convey the detail of the job, and likely duration of job, for which the Isolation is being demanded.
· The Isolating Agency shall decide whether it needs group Isolation or Individual Isolation based on the above criteria.
· After Isolation the Isolating Agency shall issue the shut down handing over formats and communicate the same to the agency who has requested the Isolation / shut down.
· If the shut down handing over formats is being issued to a Contractor then the Contractor’s supervisor shall write the name and gate pass number of the persons on the shut down format in back side of the format. In case the list is long and can not be accommodated on the work permit then the list may be attached with the request for the
permit.
· After completion of the job the working agency shall surrender the shut down handing over formats.
TRF LIMITED ( BMHE DIVISION) / OCP00 / 00
Original Issue Date: / Date of Revision : / Page 7 followed by 8
Prepared by: Sudhir Kumar / Approved by: / Issued By:
Title: POSITIVE ISOLATION PROCEDURE
· Before Lifting the Isolation the Isolating Agency shall confirm that all the shut down handing over format on the Equipment are surrendered.
· After Lifting the Isolation Isolating Agency shall advise the owner/operation for its availability.
5.3.3) RULES FOR INDIVIDUAL ISOLATION
· Equipment Locks must be attached before giving shut down acceptance and not removed until all shut down acceptance formats have been returned. This indicates that the Isolation has been carried out and verified by the Isolating Agency.
· When the Isolating Person is part of the work crew and has attached an Equipment Lock, the Isolating Person must also display the board “Men at Work” on device.
· The Isolating Person must:
i) Ensure that permission from plant operation personnel is already taken;
ii) Carry out the Isolation as per written procedure;
iii) Attach an Equipment Lock.
iv) Advise the Working agency that Isolation is complete and inform them.
5.4) Isolation for working alone:
5.4.1) General :
This procedure shall be used only where an Isolating Person wishes to isolate and be the only person (Maximum one more person is allowed) under the isolation. This procedure is permitted only when a single isolator need to be put off for taking the maintenance job. The person who is taking self Isolation must be Authorised Isolating Person for that particular job and the owner of the Energy source.