MARINE ENGINEERING DEPARTMENT

GAS WELDING REPORT

(KM104)

EN RIDWAN SAPUTRA BIN NURSAL

Student Name: MOHAMAD SYAZWAN BIN ABD AZIZ (01DKP13F2029)

DKP1

INTRODUCTION

WELDING DEFINITION

Welding is a process for joining similar metals. Welding joins metals by melting and fusing 1, the base metals being joined and 2, the filler metal applied. Welding employs pinpointed, localized heat input. Most welding involves ferrous-based metals such as steel and stainless steel. Welding covers a temperature range of 1500º F - 3000º F (800ºC - 1635ºC). Weld joints are usually stronger or as strong as the base metals being joined.

Oxy-fuel is one of the oldest welding processes. Still used in industry, in recent decades it has been less widely utilized in industrial applications as other specifically devised technologies have been adopted. It is still widely used for welding pipes and tubes, as well as repair work. It is also frequently well-suited, and favored, for fabricating some types of metal-based artwork.

TYPE OF WELDING

There are five basic types of joints:-

Butt joint - parts in approximately the same plane

Corner joint - parts at approximately right angles and arts.

Edge joint - an edge of two or more parallel parts.

Lap joint - between overlapping parts.

Tee joint - parts at approximately right angles, not at the edge of one part.

GAS WELDING DEFINITION

Gas welding is a fusion welding process.. Metal joining process in which the ends of pieces to be joined are heated at their interface by producing coalescence with one or more gas flames (such as oxygen and acetylene), with or without the use of a filler metal. Flame is used as the source of heat to melt the metals at the joint.The intense heat (flame) thus produced melts and fuses together the edges of the parts to be welded, generally with the addition of a filler metal.The most common gas welding process uses acetylene fuel, is known as Oxy-Acetylene welding. This process utilizes the heat generated by the combustion of acetylene gas (C2H2) in a mixture with oxygen.

2.2.1 GAS WELDING EQUIPMENT

Goggle to protect the eye from

excessive light

Hose red hose are use for acetylene blue hose are use for oxygen

Torch to adjust the rate of oxygen

and acetylene

Non-returning valve acetylene gas and oxygen

allow only one direction

Filler rod.

Pressure Regulator

Manifold system

Increased Efficiency more stations no downtime

Portable System

TYPE AND PROPERTIES OF FLAME

NATURAL FLAME:

− which has one-to-one ratio of acetylene and oxygen− Obtains additional oxygen from the air and provides complete

combustion

− The neutral flame has a clear or luminous cone indicating

− Used for most welding operations such as steel, cast iron, copper, aluminum and for preheating during cutting operations.

− Temperature at the inner cone tip is approximately 5850°F (3232°C)

OXIDIZING FLAME: which has an excess of oxygen.

- Has a shorter envelope and a small pointed white cone.

- The reduction in length of the inner cone is a measure of excess oxygen

- This flame tends to oxidize the weld metal.

- The temperature of this flame is approximately 6300°F (3482°C) at the inner cone tip.

- An oxidizing flame should not be used for welding steel because the deposited metal will be porous, oxidized, and brittle.

CARBURIZING FLAME: which has excess acetylene

- The inner cone has a feathery edge extending beyond it.

- If the acetylene feather is twice as long as the inner cone it is known as a 2X flame, which is a way of expressing the amount of excess acetylene.

- The carburizing flame may add carbon to the weld metal.

- It has a temperature of approximately 5700°F (3149°C) at the inner cone tips.

- A carburizing flame is advantageous to weld monel metal (certain alloy steels and hard facing such nonferrous alloys as nickel.

- Also used in silver solder and soft solder operations, only the intermediate and outer flame cones are used.

WELDING OPERATION

PRESSURE SETTING

1. Make sure all valves are closed and regulator adjusting screws are backed out

2. Set gas pressures according to the manufacturers tip charts

3. Open then close each gas valve independently to “bleed” the system

4. Set the pressures

LIGHTING UP

1. Slightly open acetylene valve and light with an approved device

2. Root flame and clear smoke

3. Open oxygen valve and set flame to neutral

4. Never light torch with both oxygen and acetylene flowing

CLOSING DOWN

1. Close oxygen valve first

2. Close acetylene valve second

3. Turn off torch

4. Close cylinder valves

5. Open then close each torch valve independently to bleed pressure

6. Back regulator adjusting screw out until loose

SAFETY PRECAUTIONS

GENERAL SAFETY PRACTISE

Area should be clear and free of combustibles

Area should be set up for free flowing movement.

Area should Be well ventilated (Doors, Fans, Vent hoods)

Fire extinguishers should be available

Area should be free of open arcs or flames

(Fireproof blankets and/or Screens are suggested)

Have work tables and machines spread out to clean.

Have easy access to fire escapes and fire extinguishers

Have your welders set up in a well ventilated area.

They should be spread out for plenty of work space.

Welding stands should be spread out and well covered.

Have Oxy-Acetylene Rig stored in a safe area.

Do not place obstructions in front of exits.

SAFETY PRACTICES OF GAS WELDING WORK

Use correct shaded lens when welding (3 or 4).

Wear heat-resistant, nonflammable gloves.

Keep area and clothes free from grease or oil.

Report defective material or tools to instructor

Welding and cutting should be done in well ventilated areas

Use soap and water to check for gas leaks

Considered oxygen as “The Most Dangerous Gas”

Know the Difference Between Oxygen and “Air”

Does Not Burn Itself, But Causes Other Materials

Keep all regulators and hoses free of oil and grease, and avoid getting grease/oil on hands, gloves and overalls.

PERSONAL PROTECTIVE EQUIPMENT

Goggle

Hand Glove

Face Shield

TOOLS REQUIRED

Spark plug

Plier

Iron brush

Chipping Hammer

Face Shield

Glove

REPORT FOR EACH TASK

PROJECT JOINT

CORNER JOINT

The common corner joints are classified as closed, half open, and full open. This type of joint is used to join two members located at approximately right

angles to each other in the form of an L. The fillet weld corner joint is used in the construction of boxes, box frames,

tanks, and similar fabrications

BUTT JOINT

A butt joint occurs when the surfaces of the members to be welded are in the same plane with their edges meeting.

Grooves are sometimes cut (for thick plates) on the edges before welding. Butt joints are often used to join pressure vessels, boilers, tanks, plate, pipe,

tubing or other applications.

LAPP JOINT

Lap or fillet joint: obtained by overlapping the plates and welding their edges.

The fillet joints may be single transverse fillet, double transverse fillet or parallel fillet joints

WORKING PROCEDURE

1) Switch on the welder machines and use 110 V on the electrode holder.

2) Clean the surface of the metal plate before welding. Placed as close to

the weld as possible to the metal plate.

3) Before striking an arc, insert an electrode to the electrode holder.

4) Adjust the electric current according to the electrode size I use

110V.Arc length between the plate and electrode about 2 mm- 3

mm.

5) Weld along the base from left to right.

6) Positioning electrode-from side 70o, and from forward 90o.

7) Wait the weld and metal become cooled.

8) Then clean the welds use chipping hammer and wire brush.

PROJECT RESULT

Butt JointLapp Joint

CONCLUSION

The experiment can be conclude, welding is used to making permanent joint on

the metal.By melting the electrode and metal. When the melt become cooled it can

combine two metal .There are problem occurs on the arc welding process is the

weld not to strong caused by the welds to small.To get a best result of this arc

welding process, student must know the angle that are used, concentration,

and the movement of the electrode and speed of moving the electrode. The best

angle for the corner joint 70o on the side view and move the electrode from left to

right. Distance between metal and electrode 3mm.The thickness of the metal and

type of the electrode are used are the factor in arc welding process.

REFERENCES

1. https://www.kleintools.com/catalog/

2.www.safetywelding/gas.com

3. M.Ramzan, I.Jusoh, Ruslan A.R.Glossari Teknologi Marin:Penerbit UTM Bhd. 1990.Pages 55-56

3.John sight.Welding Work:Wiley Publication.2004.Pages 100

5.Susannah Gardner, Shane Birley.Workshops Tools:Mc Hill.2006.Pages 23-25