Why might closing the oxygen cylinder, then the acetylene cylinder, then bleeding first the oxygen line, then finally the acetylene line at the end of a brazing project create a hazardous situation?
A) The acetylene and oxygen lines should be bled simultaneously.
B) The acetylene and oxygen cylinders should be closed simultaneously.
C) The acetylene cylinder should be closed first.
D) The last gas to go through the torch will be a flammable gas.
Question 2
When the heat load on the evaporator increases, the automatic expansion valve:
A) Closes to keep the pressure from increasing.
B) Does nothing because AEVs are not modulating devices.
C) Sends a signal to the electronic control board indicating the change.
D) Opens to feed more refrigerant.
Administer Oxygen
Cutaway of an engine showing the cylinder, piston, connecting rod, and crankshaft.
When the exhaust is rich, the output of a zirconia oxygen sensor is above 450 mV.
When the propane is shut off, the oxygen sensor should read below 200 mV.
Easy way to remember to formula to calculate volume of a cylinder
Partial pressures (in mm Hg) for oxygen (red boxes) and carbon dioxide (blue boxes) in the atmospher