CEMP-E
TI 809-26
1 March 2000
(4) Narrow root openings and narrow groove angles inhibit access to the joint root, contributing to
lack of penetration at the root and lack of fusion along the joint sidewalls. Proper joint design, preferably
using joints prequalified under AWS D1.1 should be used.
c. Position. It is preferred to weld in the flat position when making groove welds, plug welds or slot
welds, and in either the flat or horizontal positions when making fillet welds. Welding positions are
defined in AWS D1.1 in Figure 4.1 for groove welds and in Figure 4. 2 for fillet welds. To assist in
interpreting the positions given, see AWS D1.1 Figure 4.3 for groove welds, Figure 4.5 for fillet welds,
and Figures 4.4 and 4.6 for tubular joints. Welding in other than the flat or horizontal positions increases
welding time approximately four-fold, on average, increasing cost and construction time. Fewer welding
personnel are qualified by test to perform welding out-of-position. Although personnel may be previously
qualified by test to weld out-of-position, a welder may not have recently used the special techniques and
procedures for welding in these positions, and therefore may have lost some of the skill necessary to
perform quality out-of-position welding. In this case, close visual observation of the welder during the first
few out-of-position passes is especially important, and requalification testing may be necessary. The
quality of out-of-position welds is more difficult to maintain, and they typically do not have the smooth
appearance of welds performed in the flat or horizontal positions. This makes visual inspection and some
forms of NDT more difficult.
d. Joint Selection. For guidance in the selection of groove details that provide sufficient access,
limited distortion, and cost-effectiveness, the prequalified groove weld details in AWS D1.1 Figures 3.3
and 3.4 should be reviewed. The following items should be considered in selecting or evaluating joint
selection:
(1) For butt joints, partial joint penetration (PJP) groove welds are more economical than complete
joint penetration (CJP) groove welds. Provided CJP groove welds are not required by Code for the given
application or for fatigue and seismic applications, PJP groove welds should be considered for tension-
and shear-carrying joints when full strength of the connected members is not required, and for
compression splices such as column splices. PJP groove welds are prepared to a required depth of
chamfer, usually the required effective throat, or 3 mm (1/8 in.) deeper, depending upon groove angle,
welding process and position.
(2) For most applications, by Code, CJP groove welds require the use of either backing bars, which
may need to be removed in certain types of joints, or removal of a portion of the root pass area by
backgouging followed by backwelding until the joint is complete. In addition, more welding is required to
join the entire thickness of material, rather than just the amount of welding needed to carry the load.
(3) In butt joints, V-groove welds are preferred over bevel-groove welds. Bevel-groove welds are
generally more difficult to weld, especially when the unbeveled face is vertical, and lack of fusion on the
unbeveled face may result. V-groove welds, because they are balanced and usually have a downhand
position on each groove face, are easier to weld. Access to the root is also easier to achieve because of
the balance and the wider groove angle used.
(4) For tee joints, fillet welding is generally less expensive than groove welding, until the fillet size
reaches approximately 16 to 20 mm (5/8 to 3/4 in.). Above this size, PJP groove welding, or a
combination groove weld with reinforcing fillets, should be considered. There is added expense in joint
preparation for groove welds that is not required with fillet welds, however, there may be offsetting cost
savings with groove welds because of decreased weld volume, fewer passes, and therefore less labor
and materials. Less distortion may also be incurred because of the reduced weld volume.
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