Gas Welding and Cutting Safety

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Presentation Description

This Gas cutting and welding safety presentation very useful for welders, gas cutters, fabricators and trainers. This presentation I was prepared for MRF Medak plant near Hyderabad.

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Presentation Transcript

Presented by M.Gnanasekaran:

GAS WELDING AND CUTTING SAFETY Presented by M.Gnanasekaran

Objectives:

Objectives In this course, we will discuss the following: Gas welding and cutting Fire prevention Ventilation and protection Safe use, handling, and precautions to take when welding and cutting Hazard identification and elimination methods

GAS WELDING and CUTTING:

GAS WELDING and CUTTING Gas cutting is a similar process where metals/sheets/rods/other shapes are heated and to their melting point and cut/separated

Handling of Gas cylinders :

Handling of Gas cylinders Compressed gas cylinders must have valve protection caps in place and secured except when in use. Compressed gas cylinders must only be hoisted while secured, as on a cradle or pallet.

Handling of Gas cylinders :

Handling of Gas cylinders Cylinders shall be moved by tilting or rolling on their bottom edges.

Transporting of Gas Cylinders:

Transporting of Gas Cylinders Cylinders must be secured in a vertical position when transported by powered vehicles.

Lifting of Cylinders:

Lifting of Cylinders Valve protection caps must not be used for lifting cylinders. Cylinders must be secured upright except when being hoisted or carried. Never lift cylinders by the service valve or valve protection (use slings, net, etc.)

Storage of Fuel Cylinders:

Storage of Fuel Cylinders Cylinders must be secured while in use. A suitable cylinder trolley, chain, or other steadying device must be used to keep cylinders from being knocked over.

Storage of Fuel Cylinders:

Storage area must be well ventilated Valves must be closed Valve protection must be in place Cylinders must be stored in upright position Oxygen cylinders must be separated from fuel gas cylinders and combustible materials. Storage of Fuel Cylinders

Handling and using Regulators:

Use proper regulator Never use oil or grease Never stand in front of, or behind, a regulator when opening the cylinder valve! Open acetylene valve no more than ¼ turns Handling and using Regulators

Basic Rules for Oxyacetylene Welding:

Basic Rules for Oxyacetylene Welding Check adjusting screw before opening cylinder valve Blow out cylinder valve Keep tight connections between the regulator and the cylinder Release regulator Stand to one side of regulator Open cylinder valve slowly Not more than 15 psi

Basic Rules (cont.):

Basic Rules (cont.) Clean the oxygen and acetylene passages Light the acetylene gas Never use oil or grease Do not attempt to interchanges and acetylene regulators Have a qualified repair person check the regulator if it does not function properly Keep your work area clean

Safety in Gas cutting:

Safety in Gas cutting 30% Oxygen in the atmosphere will cause things to burn or explode 8 times faster Acetylene is a compound of Hydrogen and carbon(C 2 H 2 ) Produced when calcium carbide is mixed with water Needs only 10% of oxygen to ignite It is an unstable gas, will violently decompose when a pure state above 15 psi

Safety in Gas cutting:

Safety in Gas cutting Auto ignition temperature is 763 ⁰-824⁰ F. This means if acetylene reaches 30 psi in a free state, it can explode by itself without a spark of flame being present. Acetylene is a very dangerous gas

Protective Devices:

Protective Devices Pressure relief valves Back-fire arrester and flash-back arrester Fuel gas hose—red (sometimes black) Oxygen hose—green Hose protection required Pressure-reducing regulators

Acetylene Gas:

Flammable Unstable Cannot be piped above 15 psi Acetylene Gas

SAFETY PRECAUTIONS…:

SAFETY PRECAUTIONS… Valves must be closed when work is finished, cylinders are empty or when moved.

SAFETY PRECAUTIONS…:

Cylinders must not be exposed to sparks, hot slag or flame. Cylinders must not become part of an electrical circuit or have electrodes struck against them. Fuel gas cylinders must be placed with valve end up when in use. Fuel gas cylinders shall not be taken into confined spaces. SAFETY PRECAUTIONS…

SAFETY PRECAUTIONS…:

Cylinders must not be used as rollers or supports. No damaged or defective cylinder shall be used. SAFETY PRECAUTIONS…

SAFETY PRECAUTIONS…:

Before regulators are connected, valve must be slightly opened and then immediately closed to clear away dust or dirt. SAFETY PRECAUTIONS…

SAFETY PRECAUTIONS…:

Where a special wrench or suitable spanner is required to close valve, it must be left in position on the stem. SAFETY PRECAUTIONS…

SAFETY PRECAUTIONS…:

Fuel gas and oxygen hoses must be easily distinguishable from each other by color Oxygen and fuel gas hoses must not be interchangeable. Hoses must be inspected before use. Defective hose must not be used. SAFETY PRECAUTIONS…

SAFETY PRECAUTIONS…:

When not in use or work is completed: Close valve Bleed lines of pressure SAFETY PRECAUTIONS…

SAFETY PRECAUTIONS…:

Hoses, cables, and other equipment must be kept clear of passage ways, ladders and stairs. SAFETY PRECAUTIONS…

SAFETY PRECAUTIONS…:

Torch tip openings must only be cleaned with devices designed for that purpose. SAFETY PRECAUTIONS…

SAFETY PRECAUTIONS…:

SAFETY PRECAUTIONS… Torches must be inspected before each use for leaking valves, hose couplings and tip connections. Defective torches must not be used.

SAFETY PRECAUTIONS…:

Torches must not be lit from matches, cigarette lighters, other flames or hot work. They must be lighted by friction lighters or other approved devices. SAFETY PRECAUTIONS…

Never use Matches and Cigarette Lighters:

Never use Matches and Cigarette Lighters Cigarette lighters will leak gas into your pocket causing an explosion that could be fatal! Sparks can ignite matches in your pocket causing a serious burn!

Clothing:

Clothing Hats 100% cotton or wool Long Sleeve Shirt 100% cotton or wool Shoes Leather, no tongue Pants 100% cotton or wool No Shorts! Gloves Leather Jacket Leather Fire resistant cotton Welding Sleeves Leather Fire resistant cotton Jewelry Not to be worn!

FLASH-BACK AND BACK-FIRE ARRESTER:

FLASH-BACK AND BACK-FIRE ARRESTER Flashback arrestors are common safety devices that stop the progress of a flame front upstream of the insertion point. These elements quench the flame front as it propagates back upstream toward the torch and/or regulator. There are two types of sintered element arrestors. One is mounted onto the outlet of regulators and the other is mounted onto the inlet of torches.

FLASH-BACK ARRESTER:

FLASH-BACK ARRESTER The sizes of torch mount arrestors are limited so as not to make the torch too cumbersome to handle. Torch arrestors are preferred because their location is ideal for preventing reverse flow flashbacks into the hoses. If regulator mount arrestors are used, flashbacks can still occur in the hoses, with a high potential for injury.

BACK-FIRE ARRESTER:

BACK-FIRE ARRESTER Regulator arrestors are typically larger and have a higher flow capacity than torch models because the sintered element has more surface area, allowing for more flow. Regulator mount arrestors are used when higher flows are needed and these will protect regulators and cylinders from the effects of flashback.

PRECAUTION:

If flashback occurs, immediately turn off the O 2 , then the acetylene, and allow unit to cool Always work in a well ventilated area Always light the acetylene first Oxygen cylinders must be opened Never use matches or cigarette lighter 6. Use the proper regulator for each specific gas 7. Keep regulators free of oil, grease and other flammable substances PRECAUTION

PRECAUTION…:

Pressure regulators and gauges must be maintained in safe working order. Oxygen regulator exploding PRECAUTION…

PRECAUTION…:

Oxygen cylinders and fittings must be kept away from oil and grease. PRECAUTION…

Fire Extinguishers:

Fire Extinguishers TYPE “A” Used on a wood, paper or trash fir TYPE “B” Used on a fire that contained gasoline, paint or other flammable liquid. TYPE “C” Used on an electrical fire involving a breaker panel, welding machine or electric motor. TYPE “D” Is used on a fire that contains Magnesium or zinc

Fire Prevention:

Fire Prevention Hot work done in areas not free of fire hazards Precautions taken to confine heat, sparks, and slag - cannot contact flammable or combustible material.

Fire Prevention:

Fire Prevention Drums and containers of flammable or combustible liquids must be kept closed. Empty containers must be removed from the hot work area.

Ventilation and Protection:

Ventilation and Protection Local exhaust ventilation must keep smoke and fumes in the breathing zone within safe limits. Oxygen must not be used for ventilation, cooling or cleaning.

Ventilation and Protection:

Ventilation and Protection When hot work is performed in a confined space: General mechanical or local exhaust must be provided, or Employees in the space must wear supplied air respirators, and An attendant on the outside must be equipped and prepared to provide emergency aid.

Ventilation and Protection:

Ventilation and Protection Employees performing any type of welding, cutting or heating must be protected by suitable eye protective equipment.

REMEMBER… Safety is Job # 1:

REMEMBER… Safety is Job # 1

PowerPoint Presentation:

43 Getting the job done safely is the first consideration Always evaluate the job and implement appropriate safety precautions Don’t Take Shortcuts

Why do fires often occur during a cutting operation?:

Why do fires often occur during a cutting operation? Proper precautions were not taken prior to the cutting operation.

ATTENTION !:

ATTENTION ! Your safety depends on the following: Proper use of safety equipments • Proper House keeping • Proper use of hand tools Following standard operating procedures

PowerPoint Presentation:

47 Keep welding areas free of combustibles Ensure proper storage of compressed gas cylinders Ensure proper storage of compressed gas cylinders Make Housekeeping a Priority

PowerPoint Presentation:

Keep regulators free of oil, grease and other flammable substances Check valves stop reverse gas flow, they do not act as a fire stop Never starve a tip, this can cause a flashback Always keep cylinders in an upright position Never stand in front or behind a regulator when opening the cylinder valve Do not open acetylene valve more than 1 1/2 turns Always make sure area is safe and flammable free General Safety Tips…

Quiz:

Quiz 1. Fuel cylinders must be stored at least _____ feet from combustibles. 2. Shielding is a process used to protect the eyes from welding fume. True or False 3. Three physical welding hazards are ____________ radiation, infrared radiation and intense visible light. 4. You should not use oxygen as a substitute for air . True or False 5. As long as they are secure, fuel cylinders can be stored on their side. True or False

Quiz (cont.):

Quiz (cont.) 6 . Gas Metal Arc Welding is also known as _____________ welding. 7. Exposure to zinc fumes may cause metal fume fever. True or False 8. Cylinder inspection requirements are regulated by the Department of ____________________. 9. Acetylene has a very narrow flammable range. True or False 10. Backflow prevention should be provided for oxygen cylinders. True or False

Quiz Answers:

Quiz Answers 1. Fuel cylinders must be stored at least 20 feet from combustibles. 2. False. Shielding is a process used to keep air away from the weld. 3. Three physical welding hazards are ultraviolet radiation, infrared radiation, and intense visible light. 4. True. You should not use oxygen as a substitute for air. 5. False. Fuel cylinders must always be stored upright. 6. Gas Metal Arc Welding is also known as MIG welding.

Quiz Answers (cont.):

Quiz Answers (cont.) 7. True. Exposure to zinc fumes may cause metal fume fever. 8. Cylinder inspection requirements are regulated by the Department of Transportation. 9. False. Acetylene has a very wide flammable range. 10. True. Backflow prevention should be provided for all oxygen cylinders.

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