Oxygen/ Acetylene Cutting & Safety

By Keith Dover

Objectives for the Lesson

• Students will be able to identify terms associated with oxygen/acetylene cutting.

• Students will be able to label and identify parts of a cutting torch.

• Students will be able to list 3 safety procedures.

• Students will be able to identify 3 personal protective equipment pieces.

• Students will also demonstrate how to properly light torch.

• Students will also demonstrate how to shut down torch.

E-momentTake out paper and answer the following questions.

You will have 3 minutes.

• What do you know about oxygen-acetylene cutting and safety?

• What do you think you know about oxygen-acetylene cutting and safety?

• What don’t you know yet about oxygen-acetylene cutting and safety?

Pre-Test

• Take out paper and identify the following pieces of equipment:

A. B.

C. D.

E. F.

G.

H. I.

J.

K. L.

Defintions

• Oxygen- (non-flammable gas) Is not a fuel: it is what chemically combines with the fuel to the heat for cutting.

• This is called “oxidation”.

• It’s shipped in high pressure cylinders at pressures around 2200 lbs/in2

• Acetylene-(flammable gas) is the primary fuel for oxy-acetylene cutting.

• Acetylene is shipped in special cylinders designed to keep the gas dissolved.

• The cylinders are packed with porous material, then filled to 50% capacity with acetone at 250 lbs/in2.

Oxygen/Acetylene CuttingSafety Tips

Keep an approved fire extinguisher of the proper size and type in the work area. 

Inspect it regularly to ensure that it is in proper working order. 

Know how to use the fire extinguisher.

Never cut on a container that has had toxic, combustible, or flammable liquids in it.

Safety Tips (contiued)

Never perform cutting operations in an area containing combustible vapors, flammable liquids, or explosive dust.

Keep cutting apparatus clean and free from all grease, oil, and other flammable substances.

Always keep work area well ventilated.

Oxygen/Acetylene

cutting torches can be used to

cut, pierce and

gouge mild steel.

Oxygen/Acetylene Cutting

Guidelines

Oxygen/Acetylene Cutting

Oxygen/Acetylene cutting operations use fire or combustion as a basic tool. 

The process is very useful when properly controlled.

However, it can be extremely destructive if not performed correctly in the proper environment.

Oxygen/Fuel Cutting

Gas flames produce infrared radiation

This may have a harmful effect on the skin and especially on the eyes. 

Oxygen/Acetylene Cutting

Personal Protective Equipment (PPE)!

Select goggles or a mask with tempered lenses

Shaded 5 or darker to protect your eyes from injury and provide good visibility of the work.

Wear flame resistant clothing, protective gloves, sleeves, aprons and safety shoes to protect skin and clothing from sparks and slag.

Keep collars, sleeves and pockets buttoned. 

DO NOT roll up sleeves or cuff pants.

Oxygen/Acetylene Cutting

Good housekeeping practices improve the safety of any work area. 

They are essential to the safety of welding and cutting operations due to the potential hazards involved.

Oxygen/Acetylene Cutting

Warning!

Never allow oxygen to contact grease, oil, or other flammable substances. 

Although oxygen by itself will not burn, these substances become highly explosive. 

They can ignite and burn violently in the presence of oxygen.

Oxygen/Acetylene Cutting

Ventilate welding and cutting work areas adequately. 

Maintain sufficient air flow

This will prevent accumulation of explosive or toxic concentrations of gases. 

Welding or cutting operations using certain combinations of metals, coatings, and gases generate toxic fumes. 

Use respiratory protection equipment in these circumstances.

Cutting Torch Parts

Portable Oxygen/

Acetylene Cutting Rig

Pressure Settings for Oxygen & Acetylene

Regulators

• Oxygen = 20 psi

• Acetylene = 7 psi

Acetylene Regulator

Oxygen Regulator

Oxygen/Acetylene Hose

Green = Oxygen

Red = Acetylene

Cutting Torch

Parts of a Cutting Torch

Spark Lighter

Cutting Tip

Welding Tip

Heating Tip

Flashback Arrestors

Reverse Flow Check Valves

Cutting Torch Manufacturers

Oxygen/Acetylene Cutting Torch Safety

Hazards

Working Pressure Gauge Failure

Cracked Acetylene Hose

Oxygen and Acetylene Cylinders Stored

Improperly Under Stairwell

Oxygen/ Acetylene

Cutting Torch Stored

on Unsafe Cart

Oxygen/ Acetylene Cutting Torch Stored in Flammable

Liquids Cabinet

In Conclusion

1. This process can KILL you and others. Follow all safety rules.

2. Completely shut down the cutting torch when the job is completed.

• Keep all oils and grease away from the regulators.

• When oxygen is compressed with a petrochemical, it becomes highly reactive and can explode.

• Imagine a 500lb bomb exploding in front of you.

• Will there be any pieces to pick up?

Post-Test

• Raise your hand if you think you know what these represent:

A. B.

Portable

cutting rig Gauges

C. Acetylene D. Oxygen regulator regulator

E. F.

HosesGreen= OxygenRed= Acetylene Spark

Lighter

G. Cutting Torch H. Cutting Tip I. Welding Tip

J. Heating

Tip

K. Flashback L. Reverse Flow Arrestors Check Valves

Remember…

Safety is Job # 1