Most of the commercial welders are well trained in order to pass the welding tests, however there are newbies that would benefit from some tips on how to handle the situation. In general, the UA-28 pipe welding test represents a 6 inch schedule 80 pipe,

which is being done in a 6g position by using a 6010 for root pass and also a 7018 fill and cap. With the test spec, the welding test for UA-28 pipe, required 0-1/8"" land (0-3mm), while the required1/16"" to 1/8"" gap (1.6-3mm) , and with a 1/16"" (1.6mm) maximum mismatch, and a 75-100 amp range for the 6010 1/8"" (3mm) of the electrode root pass. With that test, like almost all welding tests, the difference is made by a fit up. How is this so? Let us set an example.

The tight gap requires the usage of more amperage by the commercial welder and the wider gap requires less amperage to be used. Exactly the same goes for the land...  When there is a heavy 1/8"" land, this allows the commercial welder to use more amperage than when he or she works with a 1/16"" land.  

In general, the amperage needs can differ during the welding test by as much as 25 amps depending on fit up. Thus, when the commercial welders or the industrial welders have practiced using a certain setup, they should make sure to use the exact setup on the welding test.

When performing a 6g Pipe Welding test, some of the commercial welders prefer a land between 3/32"" and 1/8"" which comes with a 3/32"" gap. With that, the commercial welder can use approximately 80 amps which is enough to start on a tack without sticking, but when it is not so hot, the keyhole gets out of hand.

The new welders should know that during the welding test, the type of the welding machine does make a difference. Some of the machines used have arc control, others have dig function. In general, the manufacturer recommends for an arc force or dig high to be set.

Yet, in case the arc force is set on the high, then this might not work right. Good results can be achieved when the dig is set on 50. If the rod is welded with multi process with mig, tig, stick, the setting of the lower arc control will work better.  

The commercial welders who go to take the 6g welding test should use the machine that is on the site. This is how they can increase their chances.

The commercial welder can ask the test supervisor about the amperage limits, the grinding, the welding procedure specification, and so on. Then one should try to have little mismatch and an even gap. The amperage should be good, the rod angle should be favorable, etc.