SAFETY DURING GAS CUTTING WELDING SAFETY IN GAS

SAFETY DURING GAS CUTTING & WELDING

SAFETY IN GAS CUTTING OPERATION

SAFETY DURING GAS CUTTING WORKS • Colour code of the Cylinder Oxygen - Black Acetylene – Maroon Nitrogen – Light Blue

STORAGE OF GAS CYLINDERS Keep minimum distance of 20 feet between fuel and oxygen cylinders

STORAGE OF GAS CYLINDERS FUEL GAS CYLINDERS (DA CYLINDERS) SHOULD BE STORED SEPERATELY FROM OTHER GAS CYLINDERS STORE CYLINDERS IN COOL, DRY AND WELL VENTILATED PLACE AWAY FROM HEAT FULL NO OTHER MATERIALS SHOULD BE STORED IN CYLINDER STORAGE AREA FUEL GAS EMPTY OXYGEN FUEL GAS EMPTY CYLINDERS SHOULD BE STORED SEPERATELY AFTER DAY’S WORK, REMOVE CYLINDER TO SAFE STORAGE PLACE

STORAGE OF GAS CYLINDERS

HANDLING OF GAS CYLINDERS KEEP CYLINDERS AWAY FROM THE SPARK OF THE FLAME DONOT LUBRICATE VALVES DONOT USE CYLINDERS AS ROLLERS OR WORK SUPPORTS KEEP ACETYLENE CYLINDERS UPRIGHT DONOT USE MAGNETS TO MOVE GAS CYLINDERS CLOSE VALVES OF EMPTY CYLINDERS DO NOT SWEETEN FOUL ATMOSPHERE WITH OXYGEN CHAIN ACETYLENE CYLINDERS UPRIGHT USE STD KEYS FOR OPENING THE VALVES USE TROLLEY FOR CYLINDERS SHIFTING

HAZARDS DURING GAS CUTTING • BACKFIRE • FLASH BACK FIRE & 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.

HAZARDS DURING GAS CUTTING FLASH BACK: • THIS HAPENS WHEN FLAME VELOCITY EXCEEDS THE GAS MIXTURE VELOCITY. • THIS COULD OCCUR WHEN THE PRESSURE INSIDE THE CYLINDERS IS CONSIDERABLY LESS.

BACK FIRE / FLASH BACK INDICATIONS • • HISSING NOISE HEAVY BLACK SMOKE SPARK COMING OUT OF NOZZLE / TIP TORCH HANDLE GETTING HOT

BACK FIRE / FLASH BACK CAUSES • • 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.

USE OF FLASH BACK ARRESTORS ARE ESSENSIAL. THEY ARE NOT SUBSTITUTE FOR SAFE WORK PRACTICES

GENERAL INFORMATION NON COMBUSTIBLE GAS CYL VALVES R H THREADS COMBUSTIBLE GAS CYL VALVES L H THREADS SNIFT VALVE BEFORE CONNECTING THE REGULATOR USE APPROPRIATE REGULATOR AND BLOW PIPE. DONOT OPEN CYL. VALVE TOO MUCH. ONE TURNING OPENING IS ENOUGH TWO STAGE REGULATOR SINGLE STAGE REGULATOR

GAS CUTTING HOSE AVOID DAMAGE TO HOSES AGAINST SHARP EDGES ETC. E R SU ES PR R LY BE SE ON UB O E R H US PE AS TY ANV C DONOT ALLOW TRAFFIC TO PASS OVER A HOSE CONNECTIONS FOR ACETYLENE FOR OXYGEN THREADED RIGHT HAND PLAIN FACETS THREADED LEFT HAND NOTCHED FACETS

OTHER IMPORTANT POINTS……… 1. 2. PRESSURE: OXYGEN - 1200 psi ACETYLENE - 200 psi EXPLOSIVE RANGE: UPPER LOWER ACETYLENE - 2. 5% 82% LPG - 2. 2% 9. 5%

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.

OTHER IMPORTANT POINTS…… 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 WELVENTILATED 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 24 V 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/CO 2 EXTINGUISHERS • INFORM NEARBY FIRE STATION WHEN IT IS UNCONTOLLABLE

SAFETY IN WELDING OPERATION

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 EQUIPMENT FOR WELDING

PPE FOR WELDING OPERATION WELDING HELMETS

LIGHT FILTERS • REDUCE INTENSITY OF LIGHT FROM THE WELDING ARC AND ABSORB ULTRA VIOLATE AND INFRA REDIATION. • THEY ARE GRADED IN ACCORDANCE WITH VISUAL DENSITY.

LIGHT FILTERS WELDINGCURRENT SHADE NO. UP TO 100 amps 100 -300 300 -400 over 400 Inert gas welding 8, 9 10, 11 12, 13 14, 15, 16, IS 5893 -1971

MOBILE WELDING SCREEN

REACTION OF BODY TO ELECTRIC SHOCK (100 VOLTS) WILL CAUSE DEATH 100 MA OR 0. 100 AMP 200 MA OR 0. 200 AMP MAY CAUSE MUSCULAR CONTRACTION 15 MA OR 0. 015 AMP 20 MA OR 0. 020 AMP MAY CAUSE SOME SENSATION 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 2 PATH OF CURRENT FLOWING THROUGH THE BODY 3 LENGTH OF TIME BODY IS IN CURRENT

WELDING AND FIRE SAFETY

FLAMMABLE AND COMBUSTIBLE MATERIAL 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