Hi, Tarek,
Just to clarify, why do you say that a pipe welded to a base plate is fillet weld. You can also have a Single Bevel CJP or PJP or if accessible you can also have a single V. It need not always be Fillet Weld.
However Mr. Anban is asking Note b on table 4.1 the term "circumferential welds" in pipes above 600
mm OD means on girth welds (Butt Joint) or inclusive of Fillet
Answer.
Note b is only referring circumferential welds for CJP and PJP and FOR BUTT JOINTS ONLY. For Fillet weld for pipe there is no diameter restriction.
Take Note that this table is ONLY for POSITION QUALIFICATION and to
answer you second question and does not state anything about diameter restrictions.
Having a PQR for 1G/2G/3G/4G. Please take note that these positions are qualified by plate, hence you have to refer to 4.13.3,3 which says that if a plate is tested as per sketch 4.25(b) with backing or back gouging, then you are qualified for T K Y Joints on pipe over 600mm.
Hope you have a better idea now.