Both are related to Pipe / tubular structure welding. These are welding position to which a welder / welding procedure is qualified to:
- 6G is a position which the tubular weld joint is inclined to 45 degree angle. So welder has to weld the test piece in that position to get qualification.
- 6GR means nothing but a restriction ring on that 6G positioned test coupon. 6GR position qualification is mandatory for welder / procedure qualification of TKY joints in tubular structural construction, see Fig. 10.20 of AWS D1.1 2020.