Title: SMAW Pipe Welding Techniques
1SMAWPipe WeldingTechniques
2Positions
31G Position
Pipe rotated, Electrode is always at the
top Either a split bead or weave technique may be
used
42G 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.
55G Position
Axis of the Pipe is Horizontal, The weld in
vertical. Progression may be up or down. A weave
bead is best used.
66G 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.
71F 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.
82F Position
Fixed Position Best to use a split bead technique
92FR Position
A split bead technique is best used.
Rotated
104F Position
A split bead technique is best used
115F 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.
12Fill Pass
Cover Pass
Root Pass
Hot Pass
13Always 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!
14Always 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!
15Techniques
- Stringer (push, drag, or whip), or Weave
16Progression (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
17Travel Speed
- Stay on the leading edge of the puddle
18Dimensions
- Reinforcement Height
- ASME flush - 1/16
- AWS flush 1/8
- Reinforcement Width
- 1/16 past bevel edge
- Smooth transition at weld toe (45o max)
19Keyholeing
20Backing
- Metallic
- backing ring
- consumable inserts
21Welding grooves with Inserts
- Keep the root opening wide
- Make the root pass in one bead
- Avoid tight areas at the weld toes
22Welding a PJP groove
- Works great for limiting restrictions inside
pipes - make up for loss of wall on reinforcement
23Root 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.
24Root 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.
25Tacking, 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 - Dont overgrind tacks.
26Butt 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
27Butt Joint Preperation
(Joints without backing)
600 included angle Root faces Tacking Feather
Tacks
28Open 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.
29Restarts
- Stagger all starts and stops or use runon, runoff
tabs - Feather all restarts start on top, or start in
front and remelt - Dont 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.
30Craters
- Fill craters by welding into the previous weld
start - Use a short arc length to control heat.
31Wagon Tracks
32Watch these areas. Be sure to keep it melted into
these spots.
33Electrode Angles
- Up Progression - always point toward center of
Pipe - Down Progression - use a steep drag angle
34Arc 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.
35Helpful 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