Oxy fuel Cutting and burning Inspecting the system

Ag Systems l Standard 8: Students will fabricate with metal. Objective 4: Use manual oxy-fuel gas cutting processes. We will Cover Perform safety inspections of equipment and accessories.

Oxy-fuel Oxyfuel is a group of processes that use heat generated as a result of the combustion of a mixture of oxygen and a combustible gas (a fuel gas). Propane, Natural, MAPP, Propylene, and Acetylene are most common fuel gasses. Each fuel gas has unique qualities and guidelines for use. Follow them!

We will cover Oxy-Fuel Cutting Oxy-fuel gas cutting is also referred to as flame cutting it is a process of cutting steel by removing material to form a slot, called the kerf. The metal is actually removed from the kerf by burning it away. Flame cutting is one of the fastest and most efficient methods for cutting thick metal.

Something to think about…… Every time you use oxy-acetylene or oxy-fuel gas equipment , if safety guidelines are not followed, it would be the same as handling live explosives ready to go off……. Now let’s talk SAFETY

Good Housekeeping 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. Keep all welding and cutting equipment clean and free of grease, oil, and other flammable substances.

Your Work Area Move combustible materials away from the work area.  If you can not move them, protect them with fireproof covers. 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.

Toxic, Combustible Flammable, Never perform Oxy-fuel Cutting operations on a container that has held toxic, combustible or flammable liquids or vapors. Never perform Oxy-Fuel cutting operations in an area containing combustible vapors, flammable liquids, or explosive dust.

WARNING! Warning! Any petroleum product 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. Even grease or oil on your hands or gloves!

Clean air supply Ventilate welding and cutting work areas adequately. Maintain sufficient air flow to prevent accumulation of explosive or toxic concentrations of gases.

PPE Personnel Protection Equipment Wear Approved Eye Protection Wear Flame Resistant Clothing Wear Long Sleeves, Pocket Flaps and No Cuffs Wear Approved Foot Gear, Leather shoes or boots preferred. (no uncovered toes) Wear Approved Hand Protection, Leather preferred. (no cloth, plastic, or rubber )

Your Eyes Gas flames produce infrared radiation which may have a harmful effect on the skin and especially on the eyes.  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. 

Welding/Cutting Goggles Used to protect eyes from damaging light rays and heat rays that may prove destructive to eye tissue. Should not be used for arc welding.

Your Clothing 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.

Protective Leather, sleeves, apron or coat Used to protect the body from harmful ultraviolet rays and hot molten spatter while cutting.

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. Report Any Damage to teacher!

Inspect the cone end, coupling nut, and torch head for dirt, dust, oil, grease, or damaged parts. Dirt and dust can be removed with a clean cloth. CAUTION: If oil, grease or damaged parts are detected, DO NOT USE! Report it to the instructor immediately!

Inspect the “O” Rings Inspect the cutting attachment cone end for missing or damaged “O” rings. Damaged or missing “O” rings can allow gases to mix and will cause backfires or flashback.

Setting up the Cutting Head Connect the cutting attachment to the torch handle and tighten the coupling nut, using hand pressure only. Wrench tightening may damage “O” rings and create a faulty seal. HAND TIGHT ONLY

Check Valves and Flashback Arrestors 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

All oxygen connections and cylinders have right-hand threads. Oxygen fittings and connectors are smooth edged.

All fuel gas connections and cylinders have left-hand threads. Fuel gas fittings have a “V” notch cut around the outside of the connectors.

Question your neighbor Which FITTING is for which GAS?

Tip Selection use a tip chart Tip charts, and cylinder capacity charts are important instructions for using oxy-fuel equipment.  Select the proper safe tip and cylinder size for the application.  Picking the wrong tip or cylinder usually results in poor performance, equipment failure, or injury. 

Inspect the Cutting Tips Inspect the torch head. The tapered seating surfaces must be in good condition. If dents, burns or burned seats are present, the seat must be resurfaced. If the torch is used with a bad seat, backfire or backflash may occur.

Attaching the Cutting Tip Wrench Tight Connecting Nut Insert the tip in the cutting attachment head and tighten securely with an open-end wrench.

Secured Cylinders RIGHT WRONG RIGHT

DO A LEAK TEST

Think about it! Don’t use matches to test for leaks.. Don’t use a system that leaks. A leaky system wastes, money, gasses, and is unsafe. There are 2 easy leak test methods one with out soapy water and one with soapy water.

Test for leaks without soap and water. How to Check for leaks in the Oxy-Fuel system. Click the button

Test for leaks with soap and water. How to Check for leaks in the Oxy-Fuel system. Click the button

If needed, tighten any connections with a smooth jawed wrench so as to not damage the brass coupling nuts.

Assignment Test for leaks on a oxygen / acetylene rig using soapy water. Your teacher will decide if this is a demonstration or a small group activity. Get the check list and soapy water from your teacher. Complete the test, record the findings on the form and turn it in to your teacher.