Fillet or groove welds can be made in all of
these positions. Figure 3-29 shows the various positions used in plate welding. The
American Welding Society (AWS) identifies these positions by a number/letter designation;
for instance, the 1G position refers to a groove weld that is to be made in the flat
position. Here the 1 is used to indicate the flat position and the G indicates a groove
weld. For a fillet weld made in the flat position, the number/letter designation is 1F (F
for fillet). These number/letter designations refer to test positions. These are positions
a welder would be required to use during a welding qualification test. As a
steelworker,
there is a good possibility that someday you will be required to certify or perform a
welding qualification test; therefore, it is important that you have a good understanding
and can apply the techniques for welding in each of the test positions.
Because of gravity, the position in which you
are welding affects the flow of molten filler metal. Use the flat position, if at all
possible, because gravity draws the molten metal downward into the joint making the
weld-ing faster and easier. Horizontal welding is a little more difficult, because the
molten metal tends to sag or flow downhill onto the lower plate. Vertical welding is done
in a vertical line, usually from bottom to top; however, on thin material downhill or
downhand welding may be easier. The overhead position is the most difficult position.
Because the weld metal flows downward, this position requires considerable practice on
your part to produce good quality welds.
Although the terms flat,
horizontal, vertical, and overhead sufficiently describe the positions for
plate welding, they do not adequately describe pipe welding positions. In pipe welding,
there are four basic test positions used (fig. 3-30). Notice that the position refers to
the position of the pipe, not the position of welding.
Test position 1G is made with
the pipe in the hori-zontal position. In this position, the pipe is rolled so that the
welding is done in the flat position with the pipe rotating under the arc. This position
is the most advan-tageous of all the pipe welding positions. When you are welding in the
2G position, the pipe is placed in the vertical position so the welding can be done in the
horizontal position. The 5G position is similar to the 1G position in that the axis of the
pipe is horizontal. But, when you are using the 5G position, the pipe is not turned or
rolled during the welding operation; therefore, the welding is more difficult in this
position. When you are using the 6G position for pipe welding, the axis of the pipe is at
a 45-degree angle with the horizontal and the pipe is not rolled. Since the pipe is not
rolled, welding has to be done in all the positions— flat, vertical, horizontal, and
overhead. If you can weld pipe in this position, you can handle all the other welding
posi-tions.
NOTE
There
is no 3G or 4G test position in pipe welding. Also, since most pipe welds are groove
welds, they are identified by the letter G.
We will discuss more about
the techniques used for welding in the various positions later in this course, but for
now, let’s talk about the effects of heat on metal.
Published
by SweetHaven Publishing Services
Based upon a text provided by the U.S. Navy
