Work permit

WORK-PERMITSYSTEM

byHansa Vyas

PERMIT TO WORK (PTW) A work permit is a document giving

permission for specific work to be carried out subject to certain stated conditions and with in a specified period of time

Safety work permit is a written document authorizing person to carry out work, warning them of the concerned dangers and spelling out the precautions needed for carrying out the job safely

WHY PERMIT TO WORK? Permit specifies the conditions and procedure

for safe execution.Basic purpose of permit system is to prevent

injuries to personnelCLZS handles Hydrocarbons. Hot metal &

toxic materials - poses special risks.Maint. Personnel are not adequately familiar

with process conditions.Operation will determine that it is safe to

perform the designated job.

Protect property from damage Avoid fireEnsure that all work is carried out in

safest possible manner.

REQUIRMENT OF PERMIT TO WORK (PTW)

Permit is required for the following jobs :Major & Minor Maint. work.Inspection.Construction.Alteration.Process Equip. cleaningEntry into confined space.Excavation.Electrical job.Height jobs etc.

WORK PERMIT NOT REQUIRED

Routine welding / cutting and similar maintenance / fabrication jobs carried in Central workshop

Routine sampling for the purpose of laboratory analysis.Replacement of control card, annunciation card / lamp,

charts, and inking of charts, panel lamp etc.Watering / gardening work relating to horticulture.Manual sweeping with or without vacuum cleaners of

plant area etc.Entry of stores vehicle for loading / unloading of material

/ Chemicals at safe place in the plant.

TYPES OF PERMITSCLASS – I PERMIT TO WORK

CLASS – II WORK PERMIT (FOR GENERAL / ROUTINE JOBS)

CLASS – I PERMIT TO WORK ALL HOT JOBS IN HAZARDOUS AREA) All types

of “Hot Jobs” in plant battery limits, LPG storage / Pipe lines, HSD/LDO storage & unloading area, handling of Acid / Alkali, jobs maintenance job in chlorine line and radiography jobs.

Hot work : is any work such as welding / cutting job, chipping by spark – producing tools etc carried out in vicinity of flammable or combustible material that is capable of causing fire condition

CLASS – I PERMIT TO WORKVESSEL ENTRY (CONFINED SPACE) A confined space is defined as an area, which may or may not

be enclosed. It is large enough and a person can bodily enter and perform assigned work. It is not designed for continuous human occupancy. It has got limited or restricted means for entry and exit.

i)It is subjected to potential hazards, viz., accumulation of toxic / flammable gas / vapour, inert gas, oxygen deficient (<20% v /v ), flooding of liquid, steam or any other hazardous substance.

Some of the examples of confined space are oil tanks, water tanks, condensate tanks, reactors, oil water sewer pits, tanker trucks, vessels, floating roof decks, ducts, etc.

HEIGHT WORKS (All types of height jobs 2 m & above, except those jobs where working platform with railing and Stairs /Monkey ladder is provided.

ELECTRICAL JOBS All types of EHT/HT electrical jobs in plants including PCC maintenance, Transformer maintenance & bus couplers maintenance

EXCAVATION JOBS Excavation jobs in plant (more than 0.5 meter deep) and cutting of roads.)

CLASS – II WORK PERMIT (FOR GENERAL / ROUTINE JOBS)

All general / routine nature of jobs in the plant / area. Isolation of Firewater network , road closure inside the plant,

WHO CAN SIGN A WORK PERMIT

Personnel who are authorized to sign on the Work Permit shall have thorough knowledge of the work to be performed and the conditions under which the work will be performed.

HOD authorizes permitees and list is circulated.

ISSUING AUTHORITY OF WORK PERMIT

Issuing authority is responsible for preparation and handing over of the equipment in safe condition to perform the work.

Authority to issue all types of work permits is generally granted to shift incharge level executive and above.

B.Sc or Diploma in Engineering with 3 yrs Experience & BE/B. tech with minimum one year Experience shall issue the Class –II work permit in plant operation areas as authorized by the plant SBU / HOD. Class- I to be issued only by Shift incharges.

PERMITEE:

CLZS employee onlyJob in-charge (work permit acceptor) is

the engineer from main. dept. such as mechanical maintenance / electrical / instrument /civil / inspection etc.

PREPARATION OF THE EQUIPMENT

Equipment electrically isolatedInspection tested (for cold & hot job)Isolated from steam, air & gasDepressurizedDrainedPositively isolated/blindedSteamed & water flushed

Ventilated & gas freedContinuous inert gas flow / continuous

adequate ventilation arranged.Vehicle/equipment in good condition with

spark arrestedRadiation source removed (Confined

space entry)

POTENTIAL HAZARDS

Lack of oxygenCO, SO2 or any other toxic gasesCombustible gasesCorrosive chemicalsSteam / CondensateHigh humidity

PROTECTION MEASURES

Protective clothingHearing protectionSafety HarnessEye protectionFace protectionRespiratory protectionKeep fire equipment stand-by

PROTECTIVE MEASURESCONTD

Barricade the areaRemove flammable and combustibleCover with fire retardant tarpaulinAttendant with Airline setKeep man ways openAllow minimum possible no. of persons inside

confined space

PROTECTIVE MEASURESCONTD

To ensure positive isolation & maintain it all through

Ensure adequate ventilation all throughDisplay copy of entry permit near entry

manhole

ELECTRICAL ISOLATIONBefore issuing a Work Permit, it is

essential to ensure that the equipment / facility to be worked on is electrically safe and electrical power is isolated to the extent necessary for the safe conduct of the authorized work.

Issuing, Executing authorities and Electrical Maintenance shall jointly decide the extent of isolation required.

‘DO NOT OPERATE’ tag shall be used when isolation by local switch is decided as adequate protection.

LOTO System to be followed.

VALIDITY OF PERMITClass-1 Work permit shall be initially

issued for a period of 8 hrs. and shall be renewed for one more shift &Class-2 for 1 day.

On need basis , permit can be given for max. 7 days period.

Clearance to be obtained every shift.Clearance to be given after physically

checking the site.

SURRENDERING WORK PERMIT

When Job is Completed the work permit should be surrendered in all the three copies.

Process In-Charge after inspecting & assuring that job is over, will acknowledge the permit in three copies.