Work Area

Area Should be Clear and Free of Combustibles

Area Should Be Well Ventilated Fire Extinguishers Should Be Available Area Should Be Free of Open Arcs or

Flames Fireproof Blankets and/or Screens Are

Suggested

Personnel Protection

Wear Approved Eye Protection Wear Flame Resistant Clothing Wear Long Sleeves, Pocket Flaps and N

o Cuffs Wear Approved Foot Gear Wear Approved Hand Protection

2

Proper Eye ProtectionLENS SHADES SELECTION

FOR OXYGEN FUEL GAS APPLICATIONS

Operation Material Size(inches)

Minimum Protective

Shade numberRecommended Shade Number*

Oxygen Fuel Gas Welding

< 1/8”1/8” to ½”

> ½”

456

4-55-66-8

Oxygen Fuel Gas Brazing 3 3-5

Air Fuel Gas Soldering 2 2-4

Oxygen Fuel Gas Cutting

< 11” to 6”

6

345

3-44-55-6

*As a rule of thumb, start with a shade that is too dark to see the weld or cutting zone.Then go to a lighter shade, which gives sufficient view of the weld or cutting zone without going below the minimum.

2A

2B

Proper Attire

Hard Hat with Visor Turned to the Back

Long Sleeve Shirt Gauntlet Leather

Welding Gloves

Industrial Quality Face Shield

Pants without CuffsHightop Leather Boots

(Steel Toes Recommended)

Oxygen Gas

Considered by Many as The Most Dangerous Gas

Know the Difference Between Oxygen and “Air”

Does Not Burn Itself, But Causes Other Materials To Burn More Vigorously

Heat of Recompression – Open Valve Slowly Keep Away From Combustibles – Especially

Oil Do Not Saturate Clothing, etc.

3

Combustion Theory

EQUILIBRIUM

3A

EQUILIBRIUM

Courtesy of CGA9A

Oxygen Cylinder

High Pressure Cylinder – 2200 PSIG orHigher

Hollow, Seamless Steel Construction

Do Not Abuse Cylinder Never Use For Other

Than Intended Use Report Any Damage

to SupplierOxygen Cylinder

High Pressure Hazard

Cap

Valve

ContentsVigorouslySupportsCombustion

4

Oxygen Cylinder Valve Compressed Gas Association

(CGA) 540 Stuck Valve – Valve Wrench

Only/Call Supplier High Pressure Safety

- Do Not Hang Objects On Cylinder

- Never Tamper With Valve Construction

- Heat Source Can “Blow” Safety

Only Fully Open or Fully Closed

Report Any Leaking or Damaged Valve to Supplier

To Oxygen Regulator

From Oxygen Cylinder

Upper Valve Seat

Lower Valve Seat

5

CGA 540

Burst Disc

Safety

Moving Oxygen or Other High Pressure Cylinders

6

Moving Cylinders Not In use:– Must Have Caps On– Do Not Lift – Roll on

Bottom Edge– Use An Approved Carrier

Moving Cylinders That Are In Use (Regulators Attached)– Must Be In An Approved

Carrier!

Using Oxygen And Other High Pressure Cylinder

Gases

7

Secure Cylinder In A Cart Or to Strong Permanent Structure

Do Not Use Near Flame, Flammables, Open Arc, Etc.

Use Only In An Upright Position Use Only In A Well Ventilated Area Always Inspect Cylinders For Damage Valve Fully Opened or Closed

Acetylene Gas

Calcium Carbide and Water Unstable and Highly Flammable Shock Sensitive Lighter Than Air Not to be used above 15 PSIG

8

Acetylene Cylinder Is Unique

Not Hollow –Acetone in Porous Monolithic Filler Material

Should Only Be Used And Stored Upright

Has Fast Acting ValveOpen ½ - 1 Full Turn

Has “Fusible Plugs” (212o F)

9

Acetylene Cylinder

Low Pressure – 250 PSIG @ 70o F Thin Walls, Welded And Easily Damaged Do Not Abuse – Can Explode If Abused Do Not Use For Other Than The Intended Use Never Use A Damaged Cylinder

– Report Damages To Supplier– Do Not Attempt To Repair Leaks– Move Leaking cylinders Outside If Permitted

10

Using Acetylene

Flammable – Keep Cylinders Away From Sources of Ignition or Heat Shock Sensitive – May Decompose Violently Limited Withdrawal Rate – “1/7th Rule” Asphyxiation 15 PSIG Maximum Use Pressure Do Not Use Copper Piping

11

Acetylene Fires

Most Fires Start In Valve Area – Check for Leaks Fusible Metal Plugs Melt At 212o F Flames – 5’ x 3’ Very Difficult To Extinguish Evacuate Area Call Fire Department

12

Alternate Fuels Propane, Propylene, Etc. Liquid Under Pressure Heavier Than Air Not Shock Sensitive Can Be Used Up To Full Cylinder Pressure Limited Withdrawal Rate – Dependent Upon Cylinder

Size, % Full and Ambient Temperature

8A

Liquid Petroleum Gas (LPG)Cylinder

Hollow, Welded, Thin Wall Cylinder Vapor Space Above Liquid

– Use Only While Standing Up Low Pressure Less Than 500 PSIG Has Fast Acting Valve

– Open ½ to 1 Full Turn

Valve Safety Relieves and Resets Never Use A Damaged Cylinder

From LPG Cylinder

To LPGRegulator

Valve Seat

Packing Nut

Handwheel

Valve Safety

9A

CGA 510 Valve

From LPG Cylinder

To LPGRegulator

Valve Seat

Handwheel

Valve Safety

Packing Nut

Oxy/Fuel EquipmentEquipment Set Up

Secure Cylinders Before Removing Caps “Crack” Oxygen Valve and Wipe Fuel Gas Valve With

a Clean Cloth Attach Regulators With Smooth Jawed Wrench Back Out Adjusting Screws Torch Valves Must Be Closed Tighten Wrench Connections According To Manufact

urers Instructions Inspect and Test Equipment

13

NEVER REMOVE THE VALVE PROTECTION CAP UNTIL CYLINDER IS

SECURED PROPERLY

6A

Secured Cylinders

13A

Tighten all connections with smooth jaw wrench

13B

Equipment Inspection

Look For Any Physical Damage Look For Other Signs of Abuse or Improper Use Look For Contamination – Oil, Dirt, etc. Clean, Replace Or Repair Before Use

14

Equipment Testing

Properly Tighten All Connections and Check To See If All Valves Are Closed

Stand To The side And Open Valves Slowly Check For Leaks

– Use Approved Bubble Solution or Pressure Test

Fix Any And All Leaks Before Proceeding

15

Before Lighting Oxy/Fuel Gas Torches

Make Sure All Valves Are Closed And Regulator Adjusting Screws Are Backed Out Set Gas Pressures According to the Manufacturers Tip

Charts Open Then Close Each Gas Valve Independently To

“Bleed” The System

Set Pressures “At Flow”

16

Lighting An Oxy/Acetylene Torch

Slightly Open Acetylene Valve And Light With An Approved Device

Root Flame and Clear Smoke Open Oxygen Valve And Set Flame To “Neutral”

– Sharp, Defined Inner Cone

Never Light Torch With Both Oxygen And Acetylene Flowing

17

Welding Flame Types

17A

Carburizing Flame

Neutral Flame

Oxidizing Flame

Lighting Equal Pressure Torches Using Alternate Fuel Gases

Open Torch Valves 1/8 to ¼ Turn Ignite Fuel Gas With Approved Igniter and Adjust Flame Introduce Oxygen And Adjust To The Desired Flame

– “Star Pattern” or Sound – Tip Edge Touching Plate

It is Permissible To Light The Flame With Both Gases Flowing– Sometimes it is Necessary

Adjusting For Large or Heating Tips:– Increase Fuel Then Oxygen In Successive Steps

17B

Lighting Low Pressure Injector Torches

It is Permissible To Light Torch With Both Gases Flowing Use Special Purge Sequence To Clear The System of

Mixed Gases Open Fuel Gas Valve ½ to ¾ Turn Open Oxygen Valve Slightly 1/8 to ¼ Turn Ignite Flame With An Approved Igniter Adjust To Desired Flame

– Tip Edge Touching Plate– “Star Pattern” or Sound

Adjusting For Large or Heating Tips:– Increase Fuel Then Oxygen In Successive Steps

17C

Turning Off An Oxy/Acetylene Torch Proper Sequence Checks Integrity of Torch Valves

Close Oxygen Valve First

Close Acetylene Valve Second

If Acetylene Valve is Leaking a Small Flame Will Continue Burning

If Oxygen Valve is Leaking, Torch Will “Pop” as Acetylene

Valve Is Closed

If Either Valve Is Leaking, Repair Before Further Use

18

Turning Off Alternate Fuel Torches

Close Fuel Gas Valve First

Close Oxygen Valve Second

This Sequence Can Prevent The Operator From Being Burned

If Fuel Pressure is Great Enough - Check Valves At Initial Light Up By Turning Oxygen Off First

18A

Shutting Down An Oxy/Fuel Torch

Overnight Or For An Extended Period of Time

Turn Off Torch

Close Cylinder Valves

Open Then Close Each Torch Valve Independently To Bleed Pressure

Back Regulator Adjusting Screw Out Until Loose

Store Hose and Equipment In a Clean Area Away From Potential Damage

19

Check Valves and Flashback Arrestors

CHECK VALVES Are a one way valve that stops the reverse flow of

gases

FLASHBACK ARRESTORS Have a special element, sintered metal filter, that can

quench a flame Generally also include a check valve

20

Check Valves and Flashback Arrestors

CHECK VALVES

Are the basic safety device

Prevents flash back accidents caused by “reverse flow” -Flashbacks can cause the most serious injuries

Check valves can fail because of “dirt” or other contamination

-Keep equipment clean -Check them periodically

21

Checkvalves

21A

HOW THEY WORK…

CORRECT FLOW REVERSE FLOW

Check Valves and Flashback Arrestors

FLASHBACK ARRESTORS Flashback arrestors are the ultimate safety device

Usually have a check valve built into it, but, can also stop a flame

-The check valve can fail because of contamination

The Heat sink element will absorb heat from a fire

The element should also be kept free of contamination and checked periodically

22

Torch vs Regulator Flash Back Arrestors

Where should Check Valves and Flashback Arrestors be Mounted

The Golden Rule: “Mount them as close to the point of mixing as possible”

Torch Mount Gives the best and most protection

May be inconvenient for the operator

Cannot be used for “high flow” applications

Are subjected to more abuse

23

Mount at the Torch vs Regulator

-continued

Regulator Mount Should use check valves at the torch also

High flow types are physically too large for torch

Take less abuse because they are out of the way

Do Not Use Both Too much restriction

Could cause other safety problems

24