safety during gas cutting & welding. safety in gas cutting operation
TRANSCRIPT
SAFETY DURING GAS SAFETY DURING GAS CUTTING & WELDINGCUTTING & WELDING
SAFETY IN GAS SAFETY IN GAS CUTTING OPERATIONCUTTING OPERATION
SAFETY DURING GAS CUTTING WORKSSAFETY DURING GAS CUTTING WORKS
• Colour code of the Cylinder
Oxygen - Black
Acetylene – Maroon
Nitrogen – Light Blue
STORAGE OF GAS CYLINDERSSTORAGE OF GAS CYLINDERS
Keep minimum distance of 20 feet between fuel and oxygen cylinders
FUEL GAS CYLINDERS (DA CYLINDERS) SHOULD BE STORED SEPERATELY FROM OTHER GAS CYLINDERS
FUEL GAS EMPTY CYLINDERS SHOULD BE STORED SEPERATELY
STORE CYLINDERS IN COOL, DRY AND WELL VENTILATED PLACE AWAY FROM HEAT
NO OTHER MATERIALS SHOULD BE STORED IN CYLINDER STORAGE AREA
AFTER DAY’S WORK, REMOVE CYLINDER TO SAFE STORAGE PLACE
FULL
FUEL GAS OXYGEN
EMPTY
FUEL GAS OXYGEN
STORAGE OF GAS CYLINDERSSTORAGE OF GAS CYLINDERS
STORAGE OF GAS CYLINDERSSTORAGE OF GAS CYLINDERS
HANDLING OF GAS CYLINDERS
KEEP CYLINDERS AWAY FROM THE SPARK OF THE FLAME
KEEP ACETYLENE CYLINDERS UPRIGHT
DONOT USE CYLINDERS AS ROLLERS OR WORK SUPPORTS
DONOT USE MAGNETS TO MOVE GAS CYLINDERS
USE STD KEYS FOR OPENING THE VALVES
DONOT LUBRICATE VALVES
DO NOT SWEETEN FOUL ATMOSPHERE WITH OXYGEN
CHAIN ACETYLENE CYLINDERS UPRIGHT
CLOSE VALVES OF EMPTY CYLINDERS
USE TROLLEY FOR CYLINDERS SHIFTING
HAZARDS DURING GAS CUTTING
• BACKFIRE
• FLASH BACKFIRE & EXPLOSION
HAZARDS DURING GAS CUTTING
BACKFIRE:
•DURING GAS CUTTING, THE DUST & DIRT COMING FROM
THE CYLINDERS BLOCK THE HOLES OF THE NOZZLE
GRADUALLY.
•OXYGEN, WHICH IS STORED AT HIGHER PRESSURE,
STARTS FLOWING TO ACETYLENE CYLINDER AND FORMS
INFLAMMABLE GAS MIXTURE.
•THIS COULD LEAD TO EXPLOSION WHEN THE TORCH IS
REIGNITED.
FLASH BACK:
•THIS HAPENS WHEN FLAME VELOCITY EXCEEDS THE GAS
MIXTURE VELOCITY.
•THIS COULD OCCUR WHEN THE PRESSURE INSIDE THE
CYLINDERS IS CONSIDERABLY LESS.
HAZARDS DURING GAS CUTTING
INDICATIONS
• HISSING NOISE• HEAVY BLACK SMOKE• SPARK COMING OUT OF NOZZLE / TIP• TORCH HANDLE GETTING HOT
BACK FIRE / FLASH BACK
• FLAME HELD TOO CLOSE TO WORK• SLAG BLOCKING TIP• HOT METAL FALLING ON AND BURNING THROUGH HOSE• FAULTY EQUIPMENT• WRONG GAS SEQUENCE DURING START- UP• INSUFFICIENT PURGING TO CLEAN HOSE BEFORE USE.• GAS HOSES DAMAGED BY PREVIOUS FLASHBACK.
BACK FIRE / FLASH BACK CAUSES
FLASH BACK ARRESTORS ARE ESSENSIAL. THEY ARE NOT SUBSTITUTE FOR SAFE WORK PRACTICES
USE OF FLASH BACK ARRESTORS
GENERAL INFORMATION
NON COMBUSTIBLE
GAS CYL VALVES R H THREADS
COMBUSTIBLE
GAS CYL VALVES L H THREADS
SNIFT VALVE BEFORE CONNECTING THE REGULATOR
DONOT OPEN CYL. VALVE TOO MUCH. ONE TURNING OPENING IS ENOUGH
USE APPROPRIATE REGULATOR AND BLOW PIPE.
SINGLE STAGE REGULATOR
TWO STAGE REGULATOR
GAS CUTTING HOSE
AVOID DAMAGE TO HOSES AGAINST SHARP EDGES ETC.
HOSE CONNECTIONS
DONOT ALLOW TRAFFIC TO PASS OVER A HOSE.
FOR OXYGEN
THREADED RIGHT HAND PLAIN FACETS
FOR ACETYLENE
THREADED LEFT HAND NOTCHED FACETS
USE ONLY PRESSURE
TYPE RUBBER
CANVAS HOSE
1. PRESSURE:
OXYGEN - 1200 psi
ACETYLENE - 200 psi
2. EXPLOSIVE RANGE:
UPPER LOWER
ACETYLENE - 2.5% 82%
LPG - 2.2% 9.5%
OTHER IMPORTANT POINTS………
OTHER IMPORTANT POINTS……
3. KEEP THE ACETYLENE CYLINDER ALWAYS
VERTICAL/UPRIGHT. IF NOT,THE LIQUID
ACETYLENE KEPT DISSOLVED INSIDE THE
CYLINDER COULD LEAK THROUGH THREADS OF
THE VALVE FITTING. THE VOLUME OF THE LIQUID
ACETYLENE, WHICH HAS COME OUT, GETS
MULTIPLIED ENORMOUSLY AND FORMS A HUGE
VOLUME OF FLAMMABLE GAS MIXTURE IN THE
ATMOSPHERE.
OTHER IMPORTANT POINTS……
4. KEEP THE CYLINDERS ALWAYS PROVIDED WITH
VALVE PROTECTION CAP.
5. USE RAMP FOR UNLOADING CYLINDERS FROM TRUCK
6. USE TROLLEYS FOR MOVING CYLINDERS FROM ONE
PLACE TO THE OTHER AND KEEP THEM CHAINED.
7. ROUGH HANDLING OF THE CYLINDER COULD
DAMAGE THE VALVE. HIGH VELOCITY GAS JET
COMING THROUGH DAMAGED VALVE WOULD MAKE THE
CYLINDER FLY LIKE A MISSILE.
8. WHEN CYLIDERS ARE REQUIRED TO BE TAKEN TO
HEIGHT, DO NOT LIFT THEM WRAPPING SLINGS
AROUND THE CYLINDERS. INSTEAD, KEEP THEM
INSIDE SUITABLY DESIGNED CAGE/CRADDLE AND LIFT
BY USING CRANE.
9. NEVER LUBRICATE THE REGULATOR SET OF OXYGEN
CYLINDERS WITH OILS/GREASE. OIL /GREASE GETS
OXIDISED. HEAT PRODUCED DURING OXIDIZATION
COULD IGNITE OIL /GREASE.
OTHER IMPORTANT POINTS……
10. KEEP STORE ROOM OF THE GAS CYLINDERS WEL-
VENTILATED AND DO NOT KEEP ANY HEAT SOURCES
LIKE OPEN FLAME, ELECTRIC OVENS ETC.
11. NEVER LUBRICATE THE REGULATOR SET OF OXYGEN
CYLINDERS WITH OILS/GREASE. OIL /GREASE GETS
OXIDISED. HEAT PRODUCED DURING OXIDIZATION
COULD IGNITE OIL /GREASE.
OTHER IMPORTANT POINTS……
12. WHILE DOING GAS CUTTING IN CONFINED SPACE,
ENSURE NO LEAKAGE IN THE SET. KEEP ALL THE
VALVE CLOSED WHEN THE SET IS NOT USED. WHEN
THE WORK IS OVER IMMEDIATELY TAKE OUT THE
SET.
13. USE 24V HAND LAMP AND PNEUAMATICALLY
OPERATED HAND TOOLS WHILE DOING GAS CUTTING
INSIDE CONFINED SPACE.
OTHER IMPORTANT POINTS……
14. BEFORE IGNITING THE TORCH ENSURE THE HOSES
ARE PURGED/FLUSHED TO LET OUT THE FLAMMABLE
GAS MIXTURE, IF ANY.
15. KEEP KEYS ON THE CYLINDER ITSELF TO CLOSE THE
VALVE IN CASE OF EMERGENCY
16. USE FLASH BACK ARRESTER
OTHER IMPORTANT POINTS……
17. WHEN ACETYLENE CYLINDER IS ON FIRE
• CLOSE THE CYLINDER VALVE. • WHEN IT IS NOT POSSIBLE USE WATER JET OR DCP/CO2 EXTINGUISHERS• INFORM NEARBY FIRE STATION WHEN IT IS UNCONTOLLABLE
OTHER IMPORTANT POINTS……
SAFETY IN WELDING SAFETY IN WELDING OPERATIONOPERATION
ELECTRIC ARC WELDING
THREE IMPORTANT CONNECTION FOR A WELDING CIRCUITS
WELDING LEAD:
CARRYING WELDING CURRENT FROM SOURCE OF SUPPLY TO THE ELECTRODE HOLDER
WELDING RETURN:
CARRYING RETURN CURRENT BETWEEN THE WORK AND SOURCE OF SUPPLY
WELDING EARTH:
CONNECTION BETWEEN WELDING CIRCUIT AND EARTH
PERSONAL PROTECTIVE PERSONAL PROTECTIVE EQUIPMENT FOR WELDINGEQUIPMENT FOR WELDING
WELDING HELMETS
PPE FOR WELDING OPERATION
LIGHT FILTERS
•REDUCE INTENSITY OF LIGHT FROM THE WELDING ARC AND
ABSORB ULTRA VIOLATE AND INFRA RED REDIATION.
• THEY ARE GRADED IN ACCORDANCE WITH VISUAL DENSITY.
WELDINGCURRENT
UP TO 100 amps
100-300
300-400
over 400
Inert gas welding
SHADE NO.
8, 9
10, 11
12, 13
14, 15
14, 15, 16, IS 5893-1971
LIGHT FILTERS
MOBILE WELDING SCREEN
REACTION OF BODY TO
ELECTRIC SHOCK (100 VOLTS)
WILL CAUSE DEATH
MAY CAUSE MUSCULAR CONTRACTION
MAY CAUSE SOME SENSATION
100 MA OR 0.100 AMP
200 MA OR 0.200 AMP
15 MA OR 0.015 AMP
20 MA OR 0.020 AMP
1 MA OR 0.001 AMP
8 MA OR 0.008 AMP
SEVERITY OF SHOCK NOT DEPENDS ON VOLTAGE ALONE BUT…..DEPENDS ON
1 QUANTITY OF CURRENT FLOWING THROUGH THE BODY
PATH OF CURRENT FLOWING THROUGH THE BODY
LENGTH OF TIME BODY IS IN CURRENT
2
3
WELDING AND FIRE SAFETY WELDING AND FIRE SAFETY
FLAMMABLE AND COMBUSTIBLE MATERIAL FLAMMABLE AND COMBUSTIBLE MATERIAL MAY BE IGNITED BY MAY BE IGNITED BY
SPARKS
HOT METAL
CONDUCTED HEAT
FLAME
ELECTRIC ARC
STRAY CURRENT
GAS WELDING TORCH
BACK FIRE IN GAS WELDING EQUIPMENT
TO PREVENT WELDING FIRES
• REMOVE FLAMMABLE AND COMBUSTIBLE MATERIAL TO A
SAFE DISTANCE
• SUITABLE FIRE EXTINGUISHER SHOULD BE READILIY
AVAILABLE
• ISSUE PERMIT-TO-WORK WHEN SPECIAL PRECAUTIONS ARE
TO BE TAKEN
TO PREVENT WELDING FIRES
• DO NOT LEAVE ELECTRIC CIRCUIT ON OR BLOW TORCHES
BURNING WHEN WELDER HAS TO BE AWAY
• AFTER THE WORK IS THROUGH DO NOT LEAVE BEHIND ANY
MATERIAL SMOULDERING
TO PREVENT WELDING FIRES
• PROVIDE SCREENS OR PARTITIONS TO PREVENT WELDING
SPARKS SPREADING AROUND
• COVER COMBUSTIBLE MATERIALS WHICH CAN NOT BE REMOVED, WITH NON-COMBUSTUBLE COVERINGS
THANK Q