JJ104 Workshop Technology Gas Equpmnt

Oxy Fuel Cutting SystemsBasic Setup & Use

Tim Turner

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 Hydrostatic tested to 3300 psi Forged from a single piece of steel -

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

– 5’ high wall– 1/2 hour fire rating

K

LK

T S D,E,Y,U,LE

Q ME MBE XAD

MD

R

Oxygen cylinder sizes:

Liquid Oxygen is stored in a dewer flask

Acetylene Cylinders

Acetone - absorbs acetylene under pressure Consumption rate = 1/7 content per hour Fusible plug - 2120 F Temperature has an extreme affect on pressure Let stand upright at least 20 minutes before using Protected valve or cylinder cap Stored away from oxygen and combustibles

– 5’ high wall– 1/2 hour fire rating

WK

WTL

WS

WCL

WC WQ

Acetylene Cylinders C2H2 - Made from calcium carbide and water

Welded construction Monolithic filler - Asbestos fibers, balsawood

(85% porus) Acetone - absorbs acetylene under pressure Fusible plug - 2120 F Consumption rate = 1/7 content per hour Temperature has an extreme affect on pressure Let stand 20 minutes before using Protected valve or cylinder cap Sold by cubic feet - determined by weight of the

cylinders

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

Procedure for changing tanks:

Continuous supply of gasses Do not allow empties to be pressurized Valves and/or checkvalves Never unsecure cylinders without protective

caps Check for Leaks MT - DATE

Regulators

Gauges - High and Low pressure Bonnet - weakest point Adjusting screw - Clockwise = On

Single stage - less expensiveDual stage - more accurate - lump on back - 200 psiNozzle Type - low volumeStem type - High VolumeGauges - High and Low pressure - bourbon tubeBonnet - weakest pointAdjusting screw - Clockwise = On

Regulators

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

What each does Preheat / Cutting hole pressures Tightening

Torch Body

single stage / dual stage

Cutting Head Preheat oxygen needle valve Seat type / Graphite type - tightening Body to head connection - tightening Oxygen lever - regulator setting, #1 needle

valve setting

Cutting Tips

1 or 2 piece sizes relate to # Drill Sizes Hand / Wrench tight

Rosebud

Tip Cleaners

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

Flame types

Carborizing Neutral Oxidizing

Starting or restarting a cut

Heat 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.

Safety

Backflash– Turn Oxygen off first

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

Headgear Assembly– Forehead pad– Proper adjustment– How to assemble – How lenses go in– Cleaning different types of lenses– Autochange hoods– Shade numbers for various things– Cracked or broken hoods– Hood designs (pipeliner, short, sock, brazing shield, handheld).