Unit 1

never open the acetylene cylinder valve more than _____. this allows for rapid closing should there be an emergency.

there are two types of torches; an _____ and an _____.

the fuel gases are _____.

the _____ allows the gas to drain slowly out of the top of the cylinder should it overheat or be put under any mechanical pressure.

its purpose is to reduce cylinder pressure to the required working pressure and produce a steady flow of gas under varying cylinder pressures.

_____ determines the oxygen and acetylene pressure settings.

a _____ mixes the acetylene and the oxygen into its correct proportions and permits the mixture to flow to the end of a tip where it can burned, providing complete control of the flame during the welding operation.

_____ becomes very unstable when compressed to more than 15 psi.

selection of the tip size is based on the _____ of the metal being welded.

a _____ is located on the bottom of the cylinder to relieve any excess pressure if the cylinder overheats.

made from seamless, drawn steel.

if it fails to return to the pin when the pressure is released, replace it. it is caused by allowing cylinder pressure to enter the gauge suddenly.

_____ is the force that distributes liquid filler metal through surface tension between the faying surfaces of the joint.

formed by a mixture of calcium carbide and water. It is highly combustible when mixed with oxygen.

reduces cylinder pressure to working pressure in two stages.

sometimes called a striker or flint igniter, and it is used to light the torch.

a _____ is used to control and direct the heat on the edges of the metal being joined.

shows the actual pressure in the cylinder. oxygen is graduated to 40000 lbs. it has a second scale that is calibrated to register the content of the cylinder in cubic feet. acetylene is graduated to 350 to 400 lbs.

shows the "working" or "line" pressure at the torch. oxygen is graduated in divisions between 0 to 200 lbs. acetylene is graduated in divisions of 0 to 30 lbs. it is usually marked with a warming color above 15 psi.

working pressure will not remain set after the torch needle valves are closed. usually the valve stem or seat is damamaged (nicked or bent), or the bourdon tube in the gauge or the regulator diaphragm has been damaged (cracked). either case calls for replacement of the regulator.

_____ is colorless gass with a very distinctive, nauseating odor.

*no intermediate chamber through which gas passes before it enters the low pressure chamber.
*gas from the cylinder flows into the regulator and is controlled entirely by the adjusting screw.

the _____ is the most widely used. It requires acetylene pressures of 1 to 15 psi. acetylene and oxygen are fed independently to a mixing chamber and then flow through the tip.

_____ must be of the same composition or compatible with the _____ being welded.

the _____ is distributed between the closely fitted surfaces of the joint by capillary action.

there are two needle valves. one regulates the flow of the _____ and one regulates the flow of _____.

*green (or black) in color. green is most common.
*connection is a solid nut with right hand threads.

a welding process that uses filler metal with a liquidus above 840 degrees Fahrenheit and belowe the solidus of the base metal.

located on the neck of the cylinder.

_____ are packed with a porous material that is saturated with acetone.

_____ is adaptable for joining or repairing metals such as cast iron, steel, malleable iron, copper, and brass. can also be used to join dissimilar metals such as joining cast iron to steel.

_____ occurs when the base metal and the added filler metal melt and blend together.

the _____ acts as a blanket that protects the weld from atmospheric contamination.

_____ is a chemical liquid that dissolves or absorbs large quantities of acetylene under pressure greater than 15 psi without changing the nature of the gas.

gas flows from the cylinder into a high pressure chamber. a spring and diaphragm keeps a predetermined gas pressure in the reducing chamber. (example: oxy = 200 psi. / Acy = 50 psi.)

made of a nonporous rubber

*red (or maroon) in color. red is the most common.
*connection is a split nut with left handed threads.

_____ is a process that produces a coalescence of metals using silver based filler metal with a melting point below that of the base metal.

_____ acts as an accelerant for the fuel gas and enables the acetylene to reach the higher temperature needed for welding and cutting.

the cylinders are charged to a pressure of _____ at a temperature of _____.

both types of regulars have _____ .

just like oxygen cylinders, _____ have a valve located on the top of the neck.

welding process that uses oxygen combined with a fuel to sustain a flame that generates the heat necessary for welding. Heat from a combination of a fuel gas and oxygen is directed to the edges of the metal to be joined.

gas passes the high pressure chamber into a second reducing chamber. an adjusting screw governs control of the pressure in the reducing chamber.

is designed to use acetylene at very low pressures, from zero to 1 psi. acetylene is drawn into the oxygen stream as the oxygen passes through a small opening. a proportion of the two gasses (equal amounts) remain constant while the torch is in operation.

There are _____ fuel gases.