intro oxyacetylene
DESCRIPTION
oxy weld description for presentationTRANSCRIPT
Introduction to
Oxy-Acetylene Welding
Welcome to the Columbus Metal Shop!
spark!
The metal shop facilities include a wide range of hot and cold metal working equipment.
The School of the Art Institute’s Columbus Metal Shop is one
of four Instructional Fabrication shops at SAIC.
The Columbus
Metal Shop is a
general access
facility set up to
provide
instruction and
material
resources for the
School’s
students, faculty,
and staff.
The Metal
Shop’s
facilities and
unique
instructional
programs
have been
structured to
meet the
needs of
students
working on a
wide range of
projects.
INSTRUCTIONALFABRICATION
Instructional
Fabrication’s mission is
to serve the
contemporary art making
needs of the School of
the Art Institute of
Chicago by providing
instruction and technical
assistance to students
and faculty using the
School’
s shops
and
fabricati
on
facilities
. Our
staff
work
collabor
atively
across
artistic
and
academ
ic
disciplin
es to
support
all
manner
s of
fabricati
ng art
objects
.
Instructional Fabrication is a division within the department of Instructional Resources & Facilities Mana
ge
Cold workingcapabilities include
• drilling• punching• mechanical fastening• roll forming• bending
• shearing
• cutting
• grinding
• sanding
• abrasive blasting
Instructional Fabrication
Table of Contents
6 GettingReady
8 Equipment forProces
s :Check
OutFromCage
10 Mat
erialConcerns
11 Mat
erialHandling
12 WeldingAnatomy & Capability
14 Turningon Fuel
16 Turning on Fue
l continued
18 Process
: Welding
20 Process
: Cutting
22 ClosingDown
: Leaving Station
Introductionto
Oxy-Acet
ylene WeldingOxy-Acetylene, commonly known as Oxy-fuel, is one of the oldest welding processes, though inrecent years, it has become less popular inindu
strialapplications. However,it is still widely usedfor avariety of applications. Oxy-fuel equipment is versatile,lending itselfto welding, brazing, braze-welding, silver soldering, metal heating (for bending and
forming) and oxy-fuel cutting.
This bookwill highlight the weldi
ng and cutting processes.
4 |The School of the Art Institute ofChicag
oInstructional Fabricatio
n |5
G
Authorizations
In order to work in the Metal Shop,you must first attend an Authorization. Authorization Sign Up Sheets and Authorization Request Forms are posted adjacent to the tool checkout area in the Columbus Wood Shop,Room 024. It is highly recommended that new patrons complete the Introduction to Metal Working Authorization before participatingin the welding authorizations.
Planning Your Project
(See also Material Concerns,page 10)
We encourage patrons to speakwith the shop’s staff about making material choices that bestsuit yourprojects before committing to a purchase—your choice ofmaterials may limit what equipment will beavailableto you.
Flammable Combustibles Prohibited
Flammable Liquids are prohibited inthe Metal Shop, including but not limited to butane lighters, propane, aerosol cans, and solvents. Use extreme caution when working near flammable materials (sketchbooks, backpacks, etcetera). Flames, sparks, and hot surfacescan cause fires.
A
P
St
wi
A
Re
H
Ti
S
Ch
P
Ch
Cu
S
St
Instructional
Fabrication | 7
E
Overview
Eye Protection
Welding Jacket
Hand Protection
Hearing Protection
RE
We
Welding Gloves
Striker
RE
Ear Muffs
We
g Jacket
Welding Tip orCuttingAttachment
Filler Material
Magnetic Clamps& Fixtures
Respiratory Protection A Welding Fume Respirator
l a
ghammer
Welding FumeRespirator
Material Concerns MaterialMaterialHandlingHandling
The Columbus Metal Shop sells steel in a variety of shapes and dimensions. Rod stock and tubing is available in rounds and squares, angle iron is availablein a variety of dimensions, and sheet metal is available in common gauges (thickness).
Linear material is sold by the foot length or in some cases full lengths averaging 12 feet. Sheet metal is soldby the square foot, with a minimum purchase requirement of 4 square feet (24” X 24”).
Types of Steel
Hot Rolled
1• Grayscale on surface
2• Clean withwire brushbeforewelding
Cold Rolled
How to CarryA separate pair of gloves for material handling is recommended—DO NOTuse Welding Gloves. Also, it is very important for your welding gloves toremain oil-free.
Use caution when entering & exiting doorways or blind intersections.
Do not try to carry long lengths or heavy material without help. Avoid walking in front ofor behindmaterials, walk
alongside.
1• Shiny, oily surface
2• Clean with orange soapand paper towels before welding.Dispose of paper in red fire-proofcan.
Beforewelding,make sureto removeall oil used
during t
hepreparationandfabrication ofmaterials.
Ke
ri
DO NOT weld on materials, including hardware, that contain:
• Paint
• Wax• Chrome Plated or
Galvanized Surfaces• Magnesium
Reuse Bin Recycle BinMaterial for the Reuse Bin must Please refrain from tossing
be approved by management. unusable material, recycle it.
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Instructional
Fabrication | 11
Welding: Anatomy & Capability
A. Mixer
There are8 mixingstationsattachedto thewall. Thisis yoursource foroxygenandacetylenefuel.
Torch Head
Barrel
CThe cutting attachment simply functions as a
convenientand economicalapproach to cutting st
eel. The cutting attachment can be used for material up to 3/4
of an i
nch thi
ck.
The mixer is where you will attach welding tips, cutting attachment, and the rosebud heating torch.
Oxygen Control Valve
AcetyleneControlValve
Acetylene Hose (red)
Oxygen Hose (green)
Mixing Chamber
Control Valve
Close up ofOxygen Control AttachmentCutting Attachment
B. Welding Tips
There are 3 types of welding t
ips available: 1, 3, 5, and 9. Tipsize will depend ontype of filler material used,see below chart.
Rosebud is a fuelintensive attachment thatshould be used withdiscretion. Pleasecheck withshop staffto seeif it might be right foryour project.
REGULATOR SETTINGS
Material Tip Size Acetylene Oxygen Filler Rod
22-18 gauge 1 8 psi 8 psi 1/16"
16-14 gauge 3 8 psi 8 psi 3/32"
12-10 gauge 5 8 psi 8 psi 1/8" Close up ofRosebud Heating Tip
1/4"-3/8" 9 8 psi 8 psi 3/16" *
* 3/16" filler rod is not available through Resale.
1 3 5 9
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TurningOn Fuel
1.
Before you begin,perform HoverTest.
Place the back ofyo
ur barehandclosetoaworksurfaceor tool befor
e touching orsetting down something heatsensitive.
Weldingtables,stationaryequipment,tools,andscrapmate
rialmightnotappearhot,butmay be hotenough to injur
eyouordamageequipment.
2.
Take enough hose off hanger carefully
sothemixer rea
ches the welding table withoutcreating a tripping ha
zard.
3. Inspect the hose for wear or damage bymaking your way from the torch handle to
theregulators.
4. Install tip into mixer, handtighten nut on top with touch tip facing to the left (for right handuse) or facing right (for left-handuse).
AB
5. Check torchhandle to makesure it is closed by gentlyturnin
g knobs counter clockwise to openand then clockwise to completely close.
AB
6. Check regulator keys to make sure they are backed out (disengaged) and approximately ½ inch
of threads are exposed.
approximately ½ inch
14
Turning On Fuel continued
7. Standing to the side of regulators, acetylene shut-off valves slowly by turning counter-clockwise until
fully opened, then close
A
9. Before the torch is lit, put on welding gloves and oxygen-acetylene goggles.
Open:Counter-clockwise
Close½turn:Clockwise
8. Open acetylene while directing welding tip towards exhaust. Turn regulator key
800
60
0
120100
80
040 60
40
20
200
1000
0
1601200
180
200
600 800
clockwiseuntil 5 psi registers onregulatorgauge, always reading in red. Then close mixer valve.
4
200
80
100 120 1000
160
1200
180NO OIL
200psi
00kPa14
Ratio 1:1
1 partacetylene to 1
800
60
00
100 12
80
060
40
40
20
200
Ac
Process:Welding
Light theTorch1. Direct
torchaway fromyou,towardstheventilation.
2. Openacetylenecontrolvalve onmixer,approximately 1/8 turn rotation counter-clockwise.
spark!
3. Light with striker. Neve
r use lighters or other sources for ignition.
2* Always position yourself with fre
sh air at your back so fumes are drawn away from you, not past you.
Adjust the Flame
4. Adjust acetylene to form feather shaped flame.
If there is too much acetylene, flame breaks awayfrom the tip. Slowly add oxygen—flame will sharpen andelongate.
Continue to add oxygen
until neutral flameis established.
And Weld!5. Focus
greencone's tip(neutralflame)onto areayou arewelding.
6. Maintainaconsistentdistancefrommaterial,heating anarrowpathbetweentwomaterials.
7. Afterpuddle isestablished,introducefiller rod.
8. Meltfillerrodintopuddleandmovealong,establishing
a weld path,often called a bead.
Weld Path
Flame Tip
ofWeld — Direction <
Welding Tip
Filler Rod
18 |TheSchool of theArtInstituteof Chicag
oInstructional Fabrication
| 19
Process: Cutting
A. Prepare Equipment
1. Inspectcuttingattachmentsbeforeuse.Ifthereappears tobegrease, oil,orequipmentdamage,returntoolsto thecageandexchangefor aworkingreplacement.
2. Insertcuttingattachmentintothetorchhandleandhandtightentheconnectionnut.
3. Adjust oxygenregulator to thepressure settingrelative tomaterialsize, seetip chartbelow.Thenopenoxygenvalve on
torchhandle.
4. Adjustacetyleneregulatorto 10psi.Thenopenacetylenevalveontorchhandle.
REGULATOR SETTINGS
Material Cutting Tip Size
Up to 10 gauge
Up to 3/16"
Up to 1/4"
Up to 3/8"
Up to 1/2"
Up to 5/8"
B. Ignite Flame
1. Openacetylene valve
on torch 1/8 turn
and light withstriker.
2. Openoxygenvalveandflameshouldappear,also
knownasacetylenefeather.Continuetoaddoxygenandreducefeatheruntilneutralflameisestablished.
3. Est
ablish puddle by maintaining a consistentdistance from ma
terial,heatinganarrow path(sameaswelding).
4. Depressoxygenlever andmove tomake cut.
Cutting AttachmentWeld Cut
Direction of Cut —>
Flame
Oxygen Lever
NOTES: Material must be supported and cut with the grain of the table, never against.
Keep feet and hose from underthe table and away from fallingmetal debris.
2
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Instructional Fabrication |21
Closing Down: Leaving Station
1. Extinguish flame by first closing oxygen at mixer.Turn torch handle knob counter-clockwise. Repeat
process toclose acetylene at mixer.
A Oxygen first,
2. Close shut-off valves turning clockwise.
Close: Clockwise
3. Bleed the line. Open acetylene at mixer and allow fuel toempty for a few seconds, a process known as bleeding the
line. Then
closeacetylene at
mixer.Repeat for
oxygen.
A
Acetylene
first, Bthen oxygen.
4. Back out regulator keys regulators, exposing approximately
5.
approximately ½ inch
Take tip off, be careful of temperature. Allow tip orattachment to cool before returning to cage!
HOT!
6. Hang hose up on wall rack in large, neat loops. Returnall the equipment back to the cage.
22 |
The School of the Art Institute of
Chicago Instructional Fabrication | 23
End Comments
Please do not hesitate to ask for help. If you are not absolutely certainabout what you are doing, or if you are having difficulty with anyaspect of the process we can help.
If the equipment is not working properly or appears to be damaged stop immediately and seek shop staff.
General Principles in Welding Steel
A well balanced neutral flame is used for welding most steels. To be sure the flame is not oxidizing, it is sometimes used with a
slight acetylene feather. A very slight excess of acetylene may be used for welding alloys with a high carbon, chromium, or nickel content. However, increased welding speeds are possible by using a slightly reduced flame. Avoid excessive gas pressure because
it gives a harsh flame. This often results in cold shuts or laps, and makes molten metal control difficult.
The tip size and volume of flame used should be sufficient to reduce the metal to a fully molten state and to produce complete joint penetration. Care should be taken to avoid the formation of molten metal drip heads from the bottom of the joint. The flame should bring joint edges to the fusion point ahead of the puddle as the weld progresses.
The pool of the molten metal should progress evenly down the seam as the weld is being made.
The inner cone tip of the flame should not be permitted to come in contactwith the welding rod, molten puddle, or base metal. The flame should be manipulated so that the molten metal is protected from the atmosphere bythe envelope or outer flame.
The end of the welding rod should be melted by placing it in the puddle under the protection of the enveloping flame. The rod should not be melted above the puddle and allowed to drip into it.
INSTRUCTIONALFABRICATION