gas cutting welding1
TRANSCRIPT
Gas Cutting&
Welding
Gas Cutting&
WeldingPPREPARED BY
SOUMEN MAKARRECLAMATION AND DREDGING WORKS
BMCT/JNPT-4
ACETYLENE CYLINDERS
Maroon in colour.
Acetylene gas (C2H2) is dissolved inacetone (liquid) and stored at 250 psi, ina specially designed cylinder.
Acetylene cylinders has a volume of 8.5m3.
Maroon in colour.
Acetylene gas (C2H2) is dissolved inacetone (liquid) and stored at 250 psi, ina specially designed cylinder.
Acetylene cylinders has a volume of 8.5m3.
Valve Protection Cap
Typical Sectional view ofValve Arrangement
Valve protection cap
ValveValve
OXYGEN CYLINDERS Oxygen is a colourless,
tasteless, and odourlessgas and is slightlyheavier than air.
Oxygen cylinder is blackin colour.
Oxygen stored at 2200psi
Oxygen cylinders has avolume of 6.9 m3
Oxygen is a colourless,tasteless, and odourlessgas and is slightlyheavier than air.
Oxygen cylinder is blackin colour.
Oxygen stored at 2200psi
Oxygen cylinders has avolume of 6.9 m3
CYLINDER STORAGE
Well ventilated room No open flame in the store 10 m distance from oxygen and acetylene
cylinders No materials that are prone spontaneous
combustion Should not be stored in direct sunlight.
Well ventilated room No open flame in the store 10 m distance from oxygen and acetylene
cylinders No materials that are prone spontaneous
combustion Should not be stored in direct sunlight.
CYLINDER STORAGE
Inflammable Gas
CYLINDER STORAGEFullEmpty
Min. 10’
Min.10’
Full CylindersEmpty Cylinders Fuel GasOxygen
Cylinders containing oxygen shall be stored separate fromcylinders fuel-gases.
Minimum 10 feet distance shall be maintained between the storageareas.
Accessories
Regulators
UNLOADING FROM TRUCK
Never drop
Use wooden Ramp and coir matters (50cmthick)
Keep the top of the cylinder up
Roll the cylinder keeping it upright
Never drop
Use wooden Ramp and coir matters (50cmthick)
Keep the top of the cylinder up
Roll the cylinder keeping it upright
Lifting cylinders by crane
Use of cradle
4-leg bridle sling
D-shackle and lifting lug
Use of Cylinder trolley
Shifting cylinders at site
Avoid Rolling & Manualcarrying
Use trolley
Keep the cylinder upright and away fromhot jobs.
Fix the DA and oxygen regulator to therespective cylinders after ensuring freefrom dirt or grease.
Connect the cutting hoses to the regulatorsand cutogen with hose clamps.Blue or blackhoses for oxygen and red for DA.
RIGHT OPERATION
Keep the cylinder upright and away fromhot jobs.
Fix the DA and oxygen regulator to therespective cylinders after ensuring freefrom dirt or grease.
Connect the cutting hoses to the regulatorsand cutogen with hose clamps.Blue or blackhoses for oxygen and red for DA.
Open the cylinder and check for leakage bysoap water test at the joints.The same to befollowed for the oxygen cylinder.Close thecylinders .
Purge the oxygen line and then the DA lineone after the other and close the valves.
RIGHT OPERATION
Open the cylinder and check for leakage bysoap water test at the joints.The same to befollowed for the oxygen cylinder.Close thecylinders .
Purge the oxygen line and then the DA lineone after the other and close the valves.
Open the DA regulator,the torch valve andlight the gas. Then open the oxygen valvesto the required pressure.
After cutting start closing from oxygen andthen DA.
RIGHT OPERATION
Open the DA regulator,the torch valve andlight the gas. Then open the oxygen valvesto the required pressure.
After cutting start closing from oxygen andthen DA.
CUTTING NOZZLESMax. Materials
thickness,(MS in mm)
Size ofnozzle
Cutting oxygenpressure in
kg/cm212255075
100150200250300
1/32”3/64”1/16’1/16’1/16”5/64”3/32”7/64”1/8”
1.43.04.04.05.05.57.58.08.0
12255075
100150200250300
1/32”3/64”1/16’1/16’1/16”5/64”3/32”7/64”1/8”
1.43.04.04.05.05.57.58.08.0
HAZARDS
FLASH BACK.
BACK FIRE.
GENERAL FIRE.
EXPLOSION.
FLASH BACK.
BACK FIRE.
GENERAL FIRE.
EXPLOSION.
FLASH BACK RETROGRESSION OF THE FIRE UPTO THE
CYLINDER.
BACK FIREBACK FIRERETROGRESSION OF THE FIRE IN THECUTOGEN.
When the blow pipe becomes hot.Nozzle blocked.Nozzle close to the job.Job close to the ground.Pressure difference between flame pressure
and the hose pressure.
REASONS
When the blow pipe becomes hot.Nozzle blocked.Nozzle close to the job.Job close to the ground.Pressure difference between flame pressure
and the hose pressure.
IF A BACK FIRE OCCURS
The blowpipe valves shall be shut off,oxygen first and then the fuel gas;
Oxygen and fuel gas cylinder valves shall beshut off;
The blowpipe shall be cooled with water, ifnecessary;
The equipment shall be checked for damageor faults, particularly the nozzle.
The blowpipe valves shall be shut off,oxygen first and then the fuel gas;
Oxygen and fuel gas cylinder valves shall beshut off;
The blowpipe shall be cooled with water, ifnecessary;
The equipment shall be checked for damageor faults, particularly the nozzle.
IF A FLASH BACK OCCURS
Cylinder valves of both fuel gas and oxygenshall be closed immediately.
(If it is safe to do so.)
Replace damaged Hoses, Blow pipe, Flashback arrestors & regulators before reuse.
Cylinder valves of both fuel gas and oxygenshall be closed immediately.
(If it is safe to do so.)
Replace damaged Hoses, Blow pipe, Flashback arrestors & regulators before reuse.
FLASH BACK PREVENTION
Purge hose pipes before lighting. Only Spark igniters shall be used to ignite Flashback arresters shall be provided at both
ends of the hoses to prevent backflow of gastowards cylinders.
Correct gas pressure and for the nozzle sizeshall be used.
Purge hose pipes before lighting. Only Spark igniters shall be used to ignite Flashback arresters shall be provided at both
ends of the hoses to prevent backflow of gastowards cylinders.
Correct gas pressure and for the nozzle sizeshall be used.
FIRE ON CYLINDER
Close the valve
Try to extinguish the fire.
Detach the regulator
Immerse the cylinder in water or apply watercopiously at the bottom half of the cylinder.
Open the valve and keep it the cool water till itbecomes empty
Do not stand in the direction of fusible safety valvefixed at the bottom of the cylinder.
Close the valve
Try to extinguish the fire.
Detach the regulator
Immerse the cylinder in water or apply watercopiously at the bottom half of the cylinder.
Open the valve and keep it the cool water till itbecomes empty
Do not stand in the direction of fusible safety valvefixed at the bottom of the cylinder.
EXPLOSION
Reasons:Fire on cylinder (pouring water on hot
cylinder)
Cylinder exposed to external heat
Rough handling
Reasons:Fire on cylinder (pouring water on hot
cylinder)
Cylinder exposed to external heat
Rough handling
Helmets with face shields
Black glass - din value 4 to 5
Leather gloves
Leather apron
Safety shoes
PPE
Helmets with face shields
Black glass - din value 4 to 5
Leather gloves
Leather apron
Safety shoes
SAFETY IN WELDINGSAFETY IN WELDING
BASIC ELEMENTSOF
WELDING
BASIC ELEMENTSOF
WELDING
SAFETY IN WELDING
The body of the welding machine shouldbe earth.
The terminals of the welding cablesshould be provided with lugs and kepttight.
The body of the welding machine shouldbe earth.
The terminals of the welding cablesshould be provided with lugs and kepttight.
SAFETY IN WELDING
The joints in the cables should be madewith terminals, kept tight and wellinsulated with heat resistant tape.
The cable should be free from jointsatleast for a length of three meters fromelectrode holder to avoid shock hazard.
The joints in the cables should be madewith terminals, kept tight and wellinsulated with heat resistant tape.
The cable should be free from jointsatleast for a length of three meters fromelectrode holder to avoid shock hazard.
SAFETY IN WELDING
Other electrical cables should not bekept laid with welding cables, to avoidinsulation damage.
For the return lead only proper cableshould be used. Using rods, angles,channels etc. Should be avoided.
Other electrical cables should not bekept laid with welding cables, to avoidinsulation damage.
For the return lead only proper cableshould be used. Using rods, angles,channels etc. Should be avoided.
SAFETY IN WELDING
Never change electrode with bare handsor wet gloves, when standing on wetfloors.
Never change electrode with bare handsor wet gloves, when standing on wetfloors.
HAZARDS
Fire Shock Health hazards
Fire Shock Health hazards
HEALTH HAZARDS
Exposure to various toxic gases generatedduring welding may produce one or more of thefollowing effects:
Inflammation of the lungs (chemical phenmonitis) Pulmonary edema (swelling and accumulation of
fluids) Chronic bronchitis. Asphyxiation.
Exposure to various toxic gases generatedduring welding may produce one or more of thefollowing effects:
Inflammation of the lungs (chemical phenmonitis) Pulmonary edema (swelling and accumulation of
fluids) Chronic bronchitis. Asphyxiation.
OCCUPATIONAL EXPOSURE STANDARDS
RELATING TO WELDING FUME CONSTITUENTOES
CHEMICALS LONG TERM SHORT TERMAluminum oxide 10 mg/m3Cadmium 0.05 mg/m3 0.05 mg/m3Chromium III 0.5 mg/m3
VI 0.05 mg/m3Copper 0.2 mg/m3Copper 0.2 mg/m3Fluoride 2.5 mg/m3Iron 5 mg/m3Lead 0.15 mg/m3Manganese 5 mg/m3Nickel (insoluble) 0.5 mg/m3
( Soluble) 0.1 mg/m3Ozone 0.1 PPM 0.3 PPMWelding fume 5 mg/m3
FACTORS TO BE CONSIDERED IN
ASSESSMENTS
Welding position
Welding location
Duration of exposure
FACTORS TO BE CONSIDERED IN
ASSESSMENTS
Welding position
Welding location
Duration of exposure
Elimination or substitution
Modification of the process or
engineering
Local exhaust ventilation
General dilution ventilation
Personal protective equipment
Preventive Measures
Elimination or substitution
Modification of the process or
engineering
Local exhaust ventilation
General dilution ventilation
Personal protective equipment
FACE SHIELD WITH ATTACHED HELMET EYE GOGGLES, FACE-SHIELD. DIN VALUE OF BLACK GLASS 12 to 14 .
HAND LEATHER HAND GLOVES (FLAME
RESISTANT) BODY LEATHER APRON & LEG GAURD.
FOOT SAFETY SHOE.
Personal Protective Equipment
FACE SHIELD WITH ATTACHED HELMET EYE GOGGLES, FACE-SHIELD. DIN VALUE OF BLACK GLASS 12 to 14 .
HAND LEATHER HAND GLOVES (FLAME
RESISTANT) BODY LEATHER APRON & LEG GAURD.
FOOT SAFETY SHOE.
HAZARDS AT SITE
Working overhead.
Working in confined spaces.
Welding or cutting tanks or vessels.
Tripping hazards.
Working overhead.
Working in confined spaces.
Welding or cutting tanks or vessels.
Tripping hazards.
Thank UThank U