190101h Oxyacetylene equipment, heating and cutting Flashcards Preview

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Flashcards in 190101h Oxyacetylene equipment, heating and cutting Deck (37)
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1
Q

What is the chemical symbol for oxygen, acetylene and propane?

A
Oxygen = O2
Acetylene = C2H2
Propane = C2H8
2
Q

Oxygen is stores at what psi?

A

2175 psi

3
Q

What happens if an oxygen, acetylene or propane tank leaks?

A

Take out of service and write a report

4
Q

What’s does the abbreviation “MT” mean?

A

Empty

5
Q

What psi does the frangible disk bust at?

Which pressurized bottle is it used for?

A

3200 psi and it’s used for oxygen bottles.

6
Q

How is acetylene made?

A

Calcium carbide mixed with water.

7
Q

How can you notice acetylene in the air?

A

It has a garlic like odour at 1% concentration.

8
Q

What does the numbers 15 psi, 28 psi and 250 psi mean when we talk about acetylene?

A

15 psi is the maximum save working pressure.

At 28 psi the gas with ignite spontaneously.

You can store the gas at a pressure of 250 psi when the bottle is fully filed with a porous filler mass + 40 % aceton.

9
Q

What’s the rate at witch you can draw the acetylene?

A

1/7 of cylinder capacity per hour.

10
Q

What are fusible plugs and what are they used on?

A

They allow acetylene to discharge if cylinder starts burning.

11
Q

At what temperate do fusible plugs melt at?

Where are they normally located?

A

At 100 degrees celcius and are located on

  • the conclaved bottom of the cylinder
  • the filled passage of the back side of the cylinder valve
  • reinforcing college or neck ring
  • the shoulder of the cylinder
12
Q

Propane range of flammability is ____%?(fuel/air mixture)

A

2.4 - 9.5 %

13
Q

Acetylene range of flammability is ____%? (Fuel/air mixture)

A

2 - 89% fuel/air mixture

14
Q

What do you not want on an oxygen bottle because of the danger it causes? Why?

A

Oil or grease because it can cause an explosion with out source of ignition.

15
Q

How are propane cylinders filled? What do they have as a safety feature?

A

You can fill it by volume or by weight.

They have relief valve.

16
Q

How much pressure can a oxyacetylene hose hold?

A

minimum 400 psi.

17
Q

What types of goggles do we use when working with oxyacetylene?

A

4# or 5# dark green shade goggle.

18
Q

when is heating or cutting metals, shop ventilation not enough?

A

When the ferrous metals have a coating of zinc, cadmium, or lead.

19
Q

What way are the threads for bottles with fuels? What about oxygen?

A

Left handed threads for fuelled bottles. Right handed for threads for oxygen bottles.

20
Q

How much do you open a oxygen valve? What about acetylene valve?

A

Oxygen valve you open all the way. Acetylene valve a full turn.

21
Q

If you need more volume of acetylene what can you do?

A

Connect 2 or more bottles together

22
Q

What are the 3 ways you can tell a acetylene hose from oxygen hose?

A
  • Left hand threads
  • acetylene fittings have groves
  • the colour of the hose could be red
23
Q

What’s the purpose of the check valves in oxyacetylene?

A

They prevent mixer of oxygen and acetylene in the hoses or regulator.

24
Q

Where is the mixing chamber on oxyacetylene equipment?

A

Torch handle.

25
Q

What are the 8 steps when purging and leak testing Oxyacetylene? (new bottles)

A

1 secure cylinder to wall
2 check all fitting and remove oil and grease
3 crack the cylinder valve one at a time to blow dust
4 attach pressure regulator, hoses and torch handle
6 retract regulator screws and open the bottle valves
7 with the torch handle valve closed adjust oxygen and acetylene pressure to 5 psi to check for leaks with approved leak tester.
8 purge each bottle at a time by opening torch valve

26
Q

How do you shut the oxyacetylene? (8 steps)

A
1 Close oxygen cylinder valve
2 open oxygen torch handle valve to release pressure 
3 retract oxygen regulator screw
4 close oxygen torch handle valve
5 close the acetylene cylinder valve
6 open acetylene torch handle valve to release pressure
7 retract acetylene regulator screw  
8 close acetylene torch handle valve
27
Q

Heating tip sizes range from?

A

00, 0 , 1 - 10

28
Q

Types of flames you will encounter are?

A
  • acetylene flame
  • carbonizing flame
  • neutral flame
  • oxidizing flame
29
Q

What are the characteristic of acetylene flames?

A
  • yellow and bushy flame
  • not a successfully used for heating
  • temperate of 800 Celsius
30
Q

What at the characteristics of carbonizing flame?

A
  • white feather is present on the flame cone.
  • excess of acetylene
  • the temperature is 3000 Celsius
31
Q

What are the characteristics of a neutral flame?

A
  • balance the oxygen and acetylene till the blue flame disappears into cones
  • the temperature is 3300 Celsius
  • recommended flame for heating and cutting
32
Q

What are the characteristics of a oxidizing flame?

A
  • the flame has excess oxygen
  • the flame cones becomes shorter, sharper and pale blue then a neutral flame. The center cone becomes longer then the others. This flame is accompanied by a harsh sound.
  • carbon will be removed from steel (softens and burns the material)
  • the flame temperature is 3500 Celsius
  • avoid oxidizing flames
33
Q

How do you set oxyacetylene regulators? (12 steps)

A

1 release regulator screw
2 slowly crack open oxygen cylinder valve to full position
3 open acetylene cylinder valve one turn
4 purge each hose individually at 5 psi (regulator 5 psi)
5 set to 2 - 3 psi on each regulator gauge
6 open acetylene torch handle valve 1/4 turn, ignite the torch and then open acetylene torch handle valve all the way
7 increase acetylene pressure with the regulator screw to a point where flame leaves the tip
8 adjust acetylene torch handle valve until the flame returns and is smoke free
9 fully open oxygen torch handle valve
10 return acetylene torch handle valve to fully open position
11 with both torch handle valves wide open, adjust the oxygen pressure regulator screw to obtain neutral flame

34
Q

Explain a back fire and why it happen?

A
  • It’s when the flame backs up into the tip and mixer, resulting in a small explosion.

Causes are:

  • to slow of a gas
  • obstruction of gas flow
  • loose or faulty seat (seals or fittings)
  • dirty tip
  • hot or worn out tip.
35
Q

Explain continuous back fire or burnback and why it happens?

A
  • it’s continuous combustion in the tip or mixer, indicated by a screeching sound and black smoke.
  • torch handle will melt
  • shut bottles off immediately

Cause are: grossly unequal pressure, Miley unequal pressure and obstruction, failure to purge each hose, lighting torch with both valves open

36
Q

What is the cutting torch start-up procedure? (5 steps)

A

1 With all torch handle valves closed, including oxygen preheat valve and oxygen regulator retracted, slowly open cylinder valves,
2 open oxygen torch handle valve fully
3 open acetylene torch handle valve 1/4 turn. Ignite torch and adjust till it’s almost out of smoke
4 open the oxygen preheat valve on the cutting attachment and adjust for a neutral flame
5 depress the oxygen lever and readjust oxygen preheat valve, with the lever depressed, to obtain a neutral flame

37
Q

What’s the proper way of torch cutting?

A

The thinner the metal the more you angle the torch