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SMAW Pipe Welding Techniques. Positions. 1G 2G 5G 6G. 1F 2F 2FR 4F 5F. 1G Position. Pipe rotated, Electrode is always at the top Either a split bead or weave technique may be used. 2G Position. Pipe Axis Vertical, Weld is Horizontal, Pipe is considered in a “fixed” position.
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Positions • 1G • 2G • 5G • 6G • 1F • 2F • 2FR • 4F • 5F
1G Position Pipe rotated, Electrode is always at the top Either a split bead or weave technique may be used
2G Position Pipe Axis Vertical, Weld is Horizontal, Pipe is considered in a “fixed” position. Always use a split bead technique Always work from the bottom up.
5G Position Axis of the Pipe is Horizontal, The weld in vertical. Progression may be up or down. A weave bead is best used.
6G Position Pipe axis is fixed in position at a 45 degree incline. Thhe position includes flat, horizontal, vertical, and overhead welds. A split bead tecvhnique is best used.
1F Position Pipe is rotated. The pipe axis is at a 45 degree incline. Welding is to occur at the top of the pipe. Split bead or weave technique may be used.
2F Position Fixed Position Best to use a split bead technique
2FR Position A split bead technique is best used. Rotated
4F Position A split bead technique is best used
5F Position Not Rotated. Progression may be up or down. Split beads or weaves can be used on 5F-up welds, split beads are best used on 5F-down welds.
Fill Pass Cover Pass Root Pass Hot Pass
Always work from the bottom up when using the split bead technique Always be careful not to create a tight area where slag may get trapped under the next weld. It is better to weave slightly than to leave a tight area. Plan your sequence of beads!
Always work toward the smaller side of the fillet. (It will be easier to get to) Always be careful not to create a tight area where slag may get trapped under the next weld. It is better to weave slightly than to leave a tight area. Plan your sequence of beads!
Techniques • Stringer (push, drag, or whip), or Weave
Progression (vertical) • Up • deeper penetration • Higher deposit rate (lb/hr) • Use near 90 degree travel angle or slightly up • Down • faster (point to point) • less penetration for thin metal • less dilution • Use steep drag angle
Travel Speed • Stay on the leading edge of the puddle
Dimensions • Reinforcement Height • ASME flush - 1/16 • AWS flush 1/8 • Reinforcement Width • 1/16” past bevel edge • Smooth transition at weld toe (45o max)
Backing • Metallic • backing ring • consumable inserts
Welding grooves with Inserts • Keep the root opening wide • Make the root pass in one bead • Avoid tight areas at the weld toes
Welding a PJP groove • Works great for limiting restrictions inside pipes • make up for loss of wall on reinforcement
Root Openings • Small will allow more amperage which will in turn make welding smoother and easier, as well as easier arc starts. • Larger root openings will allow more penetration.
Root Faces • Larger root faces will allow more amperage which will in turn make welding smoother and easier, as well as easier arc starts. • Smaller root faces will allow more penetration.
Tacking, Tack Grinding • 3/4” long • feather both ends • clean and flatten tops • start on top, burn through before end • run completely onto tack before stopping • interpass grind lumps off before next pass • stagger all starts and stops betoeen passes • stagger all starts and stops between beads in a single pass • Don’t overgrind tacks.
Butt Joint Preperation (With Backing) Root faces - 0 450 included angle Remove all mill scales and rust Tacking - not in groove Tack away from coupon area. Flush on backing
1/16-1/8 Butt Joint Preperation (Joints without backing) 600 included angle Root faces Tacking Feather Tacks
Open Root Technique • Use root opening to allow increase in amperage for smoother welding • Whip backwards for penetration • Whip forwards to reduce penetration • Do Not Weave a root pass. • Maintain a short arc gap • Stay slightly in front of the puddle at all times. Use the keyholing technique.
Restarts • Stagger all starts and stops or use runon, runoff tabs • Feather all restarts & start on top, or start in front and remelt • Don’t restart in a coupon area. • Also stagger all beads on a single pass. • Use a longer arc length when starting a weld. Compare interpass grinding techniques vs. no interpass grinding.
Craters • Fill craters by welding into the previous weld start • Use a short arc length to control heat.
Watch these areas. Be sure to keep it melted into these spots.
Electrode Angles • Up Progression - always point toward center of Pipe • Down Progression - use a steep drag angle
Arc Length • Longer arc lengths = increased puddle heat, flatter welds, deeper penetration • Shorter arc lengths = less puddle heat, flatter welds, less penetration • Use arc length to control puddle size, penetration, and burn through. • Normal arc length is 1/16” - 1/8” • Use a slightly longer arc length during a start or restart.
Helpful Tips • Clean your Welding Hood lens • Drape the cable over your shoulder or knee • Get Comfortable • Watch the puddle, not the arc • Concentrate on steady travel speed and arc length