Oxy Fuel Cutting SystemsBasic Setup & Use

Typical Torch System

• Oxygen Cylinder• Acetylene Cylinder• Method of Securing the cylinders• Caps• Regulators• Backflash arrestors• Hoses• Torch Body• Torch Head• Torch Tip• Clothing and Eye/Face Protection

Oxygen Cylinders• Oxygen is very pure - 99%• Pressure is about 2200 psi at 700 F• Forged from a single piece of steel -

no welding• Minimum of 1/4” thickness• Stored away from combustibles

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Oxygen cylinder sizes:

Acetylene Cylinders • Acetone - absorbs acetylene under pressure

• Temperature has an extreme affect on pressure

• Protected valve or cylinder cap

• Stored away from oxygen and combustibles

Oxygen Cylinder Valve

• Brass Construction

• Double back seat - NEVER LEAVE HALF OPEN

• Pop off valve - (fragile disk)

• Right hand Thread

Acetylene Cylinder Valve

• Brass Construction

• Packed valve - OPEN 1/2 TO 3/4 TURN

• Hand wheel or tank wrench - NEVER REMOVE WRENCH during use

• RH (Male) or LH (Female) Thread

Manifold Systems

• Increased Efficiency

• more stations

• no downtime

Parts:

• Cylinders• Hoses - Brass or braided• Check valves or hand valves• Flashback Arrestors - OSHA• Regulators• Main valves

Regulators• Each regulator has two gauges mounted on

a single manifold, one indicates cylinder pressure and the other indicates working pressure for the torch

• Each regulator has an adjusting screw so pressure to the torch can be quickly controlled by turning the screw righty-tighty increases pressure, left-loosey decreases pressure

Pressure Regulating Valves

Protector Cap

• Protects valve from being knocked off

• Must be in place when Regulators are off

Backflash Arrestor

• Torch / Manifold

• Regulator / torch

Hoses

• Acetylene = Red– Notch around nut means LH thread

• Oxygen = Green– RH Thread

• New Hoses have talc inside - Blow out before connecting to torch

Needle valves

Preheat / Cutting hole pressures

Torch Body

• single stage / dual stage

• Torch body is the part of the torch that is held, it contains two needle valves to control flow of gas

Cutting HeadWelding head contains mixer, mixing throat,

and the welding tip

Cutting Tips• 1 or 2 piece

RosebudFOR HEATING

Acetylene safety Precautions

• Never call acetylene “gas”

• Extremely explosive with air or oxygen

• Leave wrench on tank

Oxygen Safety Precautions

• Never call oxygen “Air”

• Never allow oxygen to come in contact with oil, grease, or other petroleum bases

• Never use oxygen for compressed air

• Never move cylinders without caps

• Always secure cylinders

•Setup Procedures for Oxy-Acetylene Systems

• Do not move cylinders without valve protection• Secure cylinders• Inspect threads• “Crack” Oxygen Valve• Attach regulators and tighten• Blow talc from new hoses• Attach Flashback arrestors, check valves, hoses,

check valves, torch body, torch head, and tip• Properly pressurize torch and check for leaks

Procedures for Lighting Oxy-Acetylene Systems

• SCREW ADJUSTING SCREW OUT• Stand to the side of the adjusting screw• Open tanks one at a time (Oxygen wide, Acetylene 1/2

turn)• Adjust regulators• Bleed lines one at a time• Fine adjustments made while bleeding the hoses• Open the acetylene needle valve and light torch• Open high pressure oxygen needle valve wide• Adjust to a neutral flame

Shut Down Procedure for Oxy-Acetylene Systems

• Turn off acetylene needle valve

• Turn off preheat oxygen needle valve

• Turn off tanks

• Bleed lines one at a time

• TURN ADJUSTING SCREWS OUT

• Turn off all needle valves

Starting or restarting a cutHeat the starting pointMove the oxygen hole off the edge of the plate and start the oxygen stream

Resume Cutting

Offhand Cutting Techniques

• Rolling your hands– “Pre-load” your wrist and forearm

– Roll, don’t slide for a smoother cut

• Sliding the torch through your fingers– Apply pressure to torch tubes with thumb and index

finger

– Keep other three fingers in fist

– Don’t move the torch body hand during stops and starts.

Beveling Angles

• Slide the torch through your fingers toward you.

• Only move the hand nearest the flame when continuing the cut.

• Keep your other three fingers in your fist. This will keep your hands cooler and allow you to make a better cut.

Terms and Definitions• Penetration: Distance from the original

surface of the base metal to that depth at which fusion stops.

• Base Metal: Metal to be welded

•Fusion Welding: process that joins metals by heating them to a melting point and allowing them to fuse or flow together.

• Backfire: A short pop of the torch flame followed by extinguishing of the flame or continued burning of the gases.

•Flashback: when the torch flame moves into or beyond the mixing chamber.

•Tack Weld: A short weld used to hold workpieces together

• Preheating: Heating prior to a welding or cutting operation

Safety

• Watch where you cut– Don’t blow molten metal toward another

person– Don’t melt the hoses– Don’t drop metal on hoses– Don’t let hoses lay on hot metal

•Release adjusting screw on regulators before opening valves

•Stand on the opposite side of the regulator when opening a valve•Open cylinder valve slowly, oxygen first all the way open and acetylene just a quarter of a turn•Do not use or compress acetylene at pressure higher than 15 psi.

•Light acetylene first, shut it off first

•Never use oil on regulators or any equipment

•Do not use oxygen as a substitute for compressed air•Keep heat, flames and sparks away from combustibles.•Keep hoses out of sparks or spatter to prevent leaks

•Never use Leather Gloves to pick up metal; use pliers

•Wear welding goggles or a face shield with a lens no. 4-6.

• Never wear synthetic clothing; wear cotton.

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