General 1
What is the maximum safe working pressure for acetylene?
15 p.s.i.
When lighting an oxy-acetylene torch, which gas do you light first?
ALWAYS acetylene first.
When opening an acetylene tank, how far should the valve be opened?
1/4 to 1/2 turn
When opening an oxygen tank, how far should you open the valve and why?
Open the tank all the way because the valve is double-seated and may leak if only partially opened.
Does oxygen burn?
No but it is an accelerant of any flame.
There is approximately __% oxygen in normal air. Oxygen tanks contain around __% pure oxygen.
Air = 21%
Oxygen tanks (industrial) = 99.5%
After lighting the acetylene, what do you do next?
Add the oxygen until you have created a neutral flame.
Before attaching a new regulator to a cylinder, what should you do what?
Open the valve slightly to blow out any debris.
True or False: Oxygen is not air.
True
When using torches, never wear loose ____________.
Clothing
What safety device is used to prevent gas from flowing backwards?
Check valve
Hoses for oxygen are colored ______________ and hoses for acetylene are colored _______________.
Oxygen = Green
Acetylene = Red
When you open the valve on a oxygen cylinder, stand to the _________________ of the regulator.
Opposite Side
NEVER use __________ on the threads of hoses or regulators.
Oil
Oxygen is an accelerant and causes anything to burn ____________________ and ________________.
Hotter and Faster
What safety device prevents fire from traveling backwards?
Flashback Arrestor
True or False: When changing a hose or gauge on a cylinder/torch, only hand-tighten the nut.
FALSE. Use a crescent wrench to tighten the connection(s).
What is the correct shutdown sequence for an oxy-acetylene torch?
The oxygen first, then the acetylene.
What type of flame is most always used when brazing/welding?
A neutral flame.
Before moving any cylinders, always make sure that they are _____________________.
Secured (chained, spring-tied, etc.)
Name the three types of torch flames.
Oxidizing, Neutral, and Carburizing
After changing a hose or regulator on the cylinder, what should the very next step be?
Open the valve and spray the connection(s) with soapy water (or Big Blu).
If the torch produces a loud "pop!" and the flame goes out, what has occurred?
Backfire
The area where you are welding or cutting needs to be free of ______________ or ____________ materials.
Combustible or Explosive
Is it okay to leave pressure in the regulators/lines when the torch is not in use? Why?
No. Always bleed the system completely. If pressure is left in the regulator, the regulator can be damaged.