Post on 14-Oct-2015
description
Permit To Work System
Engr. Muhammad Sajid
Lecturer
Department of Chemical Engineering, UOG
Industrial Management
SAFETY
Scope of The Session
1. Permit to work system General
Requirement
2. Isolation from hazardous materials
3. Isolation from sources of energy
4. Hot work
5. Work at height/roofs
6. Confined space entry
PTW - Participants All persons approved either to issue or
accept permits to work should have
received sufficient training and on job
experience.
This session shall be validated and recorded
by management.
This requirement also applies to contractors
staff, if working independently.
1. Permit to work system
General Requirement
Work Permit System
Hazard Identification
Obvious Hazards
Potential Hazards
Work Permit System
Takes care of Hazards from :
Electrical Source
Instruments Interlocks
Pressure
Temperature
Hazardous Materials
Others
Work Permit
When Needed
When agency doing the job does not
have operating control of the Equipment.
Types of Permits
Cold Work Permit
Hot Work Permit
Entry into confined spaces
Working on Height
Excavations/break-ins (walls/ceilings)
Electrical Isolation.
DCS Permit???
Basic Characteristics of Work Permit Clear and complete job description.
Location of the work - Area
The time span - date and time the permit comes into effect and the period of validity.
All known hazards to be listed.
List precautions to be taken to address these hazards. (Job Risk Assessment)
Electrical, process and mechanical isolation
One permit for one job for one equipment to be issued.
Communicate/reference to all other permits / authorizations.
Define PPEs
Any other precaution.
Cold & Hot Work Permits
Vessel Entry & working at Height Work Permit
Documentation
Display hard copy of the PTW at the work
site for checking
Issuer to keep the upper copy
After the completion of the job,hard copy to
be retained by the issuer& upper copy by
the receiver for audit purposes.
Work Permit Validity
Cold Work Permit:-8 Hrs(Extendable for 30 minutes by the
going shift in charge only)
Hot Work Permit:-8Hrs(Extendable for 30 minutes by the
going shift in charge only)
Vessel Entry Work Permit:-8 Hrs only, Not Extendable.
Excavation & Break-in:-8Hrs(Extendable for 30 minutes by
the going shift in charge only)
Incase after the issuance of work permit job is not
started within 2 hrs, issue the new work permit.
During emergency all work permits will be suspended.
Work Permit
Issuing Authority
Shift Engineer/Field Engineer/ Supervisor
authorized by Unit Manager.
Work Permit
Receiving Authority
Area Managers/ designated staff
of the Engineering departments.
A joint visit of the issuer and the acceptor to the site of the work is almost always
essential to discuss the hazards associated
with that job.
The signature of the issuer AND the acceptor should be recorded on the permit
Remember
The permit itself does not
make the job safe!
Joint Visit ????
Issuing Authority
Role of Issuing Authority Evaluate and discuss with the Receiving authority
the risks involved and precautions needed (Joint Visit) Joint visit is mandatory even for routine work permit jobs.
Determine Impact on other activities on the plant.
Ensure that work does not constitute an unauthorized Modification(if yes, then work after following Plant Modification & Control Procedure SP-8-00-048 & approval)
Inform to all people before work start who might get affected due to job.
Ensure that all pre-requirements of the job are fulfilled
Continued
Role of Issuing Authority
Ensure Process isolation
Ensure that procedure is complete in its entirety.
Enter the proper PPEs in work permit.
Ensure Electrical isolation (Electrical isolation must be check physically by giving start signal)
Ensure the job is proper hand over.
Job status at the end of the job completion.
Ensure that job is done within the intent of the work permit. Visit Site frequently
Extend the permit time(30 minutes), if job not completed within the shift. The new shift will issue the new permit.
Receiving Authority
Role of Receiving Authority
Together with issuer assess risks and take all precautions to make the job safe (Joint visit)
Explain to the subordinates/worker the hazards of the job and precautions to be taken.
All Engineering equipments are FIT FOR USE
Provide PPEs, as written in Work permit
Display the Work permit at work place
Stop the job if the environment/situation changed during work (ask for new work permit as per new situation/environment)
Continued
Role of Receiving Authority
Explain to persons executing the job, any specific permit requirements during the job.
Ensure that job status at the end of the day / shift / time allocated is communicated to the issuer and permit is returned to the issuer with job status & mentioned closing time on it and signed by both Receiving & Issuing authority.
Housekeeping of the area after the job.
Work Permit System
Take care of pre-requisites of Job
Isolation from Electrical Source of Energy
Isolation from Instruments Interlocks.
Isolations from Pressure Energy
Isolations from High Temperatures.
Removal of Hazardous / Toxic Materials
(Process Isolation)
Pre requisites of Job Process Isolation
Breaking Flanges
Inserting Blind Plates
Double Block and bleed
Closing / Tagging/ Chain Locks of Valves
Instruments Interlocks
Make it ineffective.
Remove Fuses
Electrical Isolation
Stop the machine first
Remove Breaker /Fuses (Rack out) and Tag the isolation Panel.
Pushing in of Emergency stop switch is not an approved method of Electrical Isolation
Process Isolation
Confirmation Through
Opening Vents.
Opening Drains
Through Pressure Indicators.
Cracking Flanges
De-contamination test through Laboratory
Work Permit System
Also takes care of POST job requirement
Area Housekeeping
Job status communication
Exchange of Work Permit copies.
Thoroughly checking of the area.
Electrical de-isolations.
Process de-isolations
Checking of smoldering after every 30 mins.(2 hours)
Hot Work Permit -
Requirement
Hot Work Any activity which generates heat, friction
or sparks(welding, cutting, grinding, heat
treatment)
Opening or working electrical equipment in
a hazardous area
Introducing equipment into a hazardous
area which is not properly certified.
ALL require an air test for flammable
atmosphere
Hot Work Permits Requirements To be accompanied by Cold Work Permit(depend).
Depressurize/ Purge / Flush equipment for removal of any combustible materials and get checked LEL % in the area.
Arrange trained Fire Watch.
Make available Fire Extinguisher of suitable type.
Ensure availability of all requisite fire fighting arrangements.
Make area wet ( If required ).
Make a tent ( If required )
Make available Fire Blanket.
Check area after the job for any smoldering debris.
Working At Height
Requirement Working At
Height 1-Area barricade. 2-Communication System & Observer.
3-Working platform as per standard provided with
Toe board
Guard rails , mid rails
Fixing of planks
Safety net(if required)
Provision of ladder for safe approach.
4-Ensure fall arresting (full body harness), mandatory at 2meter &
above.
5-Inspection of scaffolding prior to start work.(craft inspector).
Confined Space Entry Work
Permit - Requirement
Regulatory Requirement
o OSHA 29 CFR 1910.146: Permit-Required Confined Spaces - (Jan 1993)
o Identify Confined Spaces in Workplace
o Identify hazards in these spaces
o Identify procedures for controlling these hazards
o Train employees on confined space entry
o Keep records of compliance & training for all confined space activities
What is a
Confined Space?
o Large enough that an employee can enter and perform
assigned work
o Has limited or restricted means for entry or exit
o Not designed for continuous employee occupancy
o Entry - includes insertion of a persons head
Examples of Confined Spaces Vessels Reactors And tanks
Boilers
Chimneys
Holes in the ground
Drains
Manholes
pits
Principles for Safe CSE
Positive Isolation.
Clean
Ventilate
So that entry can be achieved safely
without the need for breathing apparatus
Testing the Atmosphere
The person authorized to issue entry permits
should specify in WRITING the
requirements for atmospheric testing,
covering gases to be tested for, points to be
samples and testing frequency (minimum
once every 4 hours).
Atmospheric Hazards
o Oxygen Levels - below 19.5 % or above 23.5%
o Flammable/Explosive exceeds 10% of Lower Explosive Limit (LEL)
o Toxic Substances exceed Permissible Exposure Limits (PEL)
o Beware of the use of nitrogen
Use of Tools in Confined
Spaces
Ensure tools including lights and electrical
items will be safe in the confined space
especially if flammable vapors may be
present(24 volts power supply only)
Rescue Plan
This should be prepared BEFORE entry
Communications - outside help
Specify duties of stand-by person
call for help, do NOT enter
Rescue personnel must be trained and fit
Provision of lifelines, harnesses, stretchers,
man hoists(if required),SCBA etc. to be
confirmed.
Before Approving Entry
Issuer should personally check all the
isolations
Check the certificate of air analysis &
others from Lab.
Ensure adequate standby provision.
Ensure there are back-up facilities to carry
out a rescue
Electrical Isolation Certificate
Request for de-isolation will be generated by operation department.
Switch off circuit breaker/starter of desired equipment.
Rack out / withdraw complete switchgear assembly from panel.
Detached Fuses (if available in circuit)
Earthing switch is applied in case of MV circuit only.
No voltage, confirmation from circuit breaker output and load point by
using standard VOLTMETER.
Apply the pad lock on Circuit breaker/MCC starter.
Use DO NOT OPERATE tags.
Equipment will be handed over to operation department along with signed
copy of isolation certificate
Electrical De-isolation
Removal of DO NOT OPERATE tag. Removal of pad lock from Circuit breaker/MCC starter. Disconnect Earthing switch in case of MV circuit only. Insert Fuses (if available in circuit). Rack in switchgear assembly in panel. Switch ON circuit breaker/starter of desired equipment. Voltage Supply confirmation from circuit breaker output and load point by using standard VOLTMETER
Equipment will be handed over to production department
along with signed copy of de-isolation certificate
Some Examples For
Discussion
False Information.
Area safety lock on & tag on .
All valves tagged.
Isolation, depressurization,
flushing & purging not required.
Nominated operator presence.
False Information.
Lines disconnected & blinded
Safety lock on & tag on.
Vessel is hot. Communication system
False & Missing Information
lock on & tag on.
After closing valves tagged. No information about adjacent area safe for spark.
No information about explosivity lab test.
No information about the use of copper hammer.
Status of the job. Closure time. Plant shift Engineer signature at closing.
Thanks Any Question