1g,2g,3g,4g..

[Day Welding]

So i have been reading up on pipe fitting/welding, as has been the norm for the last few momths. I would like to know what the 1g,2g,3g,4g business is in pipe welding. I would also like to thank everyone for the responses to my other thread. you all are great.

[Black Wolf]

You are confusing terminology. There are 4 Basic "positions" for pipe.

1G - Pipe is Horizontal, Groove is Vertical, and pipe is rotated.

2G - Pipe is Vertical, Groove is Horizontal, pipe is fixed.

5G - Pipe is Horizontal, Groove is Vertical, pipe is fixed.

6G - Pipe is inclined 45 degrees from Horizontal and fixed.

There are more depending on certification, but these are more or less the basics.

Now to further explain:

Plate work:

1G - In position

2G - Horizontal

3G - Vertical

4G - Overhead

1F - In position - looks like a 'V'

2F - In position - looks like and upside down 'T'

3F - Vertical

4F - Overhead.

2GF or 4GF (as examples) are combination Groove and Fillet welds done with a permanent backing strip that is removed before cutting up and bend testing.

Hope that helps.

[enlpck]

Note that 1G, 2G, etc specify TEST positions for qualifying welders. Each TEST position qualifies the welder for a certain range of work positions.

For example: a 1G plate, which is a groove weld in the 'flat' position (limits: the axis o the groove is within 15 deg of horizontal, and the plates are within 5deg of horizontal rotation about the axis) qualifies a welder to weld in the flat position with limits of 15deg from horizontal for the axis and 30deg rotation from horizontal about the axis (ASME SecIX)

Some test positions cover the work range of other test positions. For example, 6G covers ALL work positions (flat, overhead, vert, horizontal, etc) but 3G (vertical) covers only 1G (flat), NOT 2G (horizontal)

Also note that, with pipe, diameter matters. Testing on plate only covers pipe>24" dia. , but testing on pipe covers plate. Testing on pipe will give diameter limits, as well (for example, a pipe < 2-7/8"OD allows welding pipe down to 1"OD, but no smaller)



See: http://www.sperkoengineering.com/html/Position.ppt for more information. Mr. Sperko has been on the SecIX committee for a good while, and explains the rules (for ASME.... other codes are similar, but not identical) very, very well.

[Day Welding]

thanks guys. i copied and saved the advice. good to know.