120103j Flashcards
What are 3 important dimensions of pipe?
OD
ID
wall thickness (schedule)
Are the following statements regarding pipe true or false?
a) _____ OD is identical to the nominal pipe
b) _____ nominal size is aprox ID of standard pipe wall
c) _____ pipe schedules are an indication of wall thickness
d) _____ the terms tube and pipe are interchangeable
e) _____OD of a pipe remains the same regardless of it schedule
f) _____pipe 350mm (14”) and larger is identified by OD
a) F- OD is aprox = to ID for pipe ≤12”
b) T
c) T
d) F - tube and pipe are not interchangeable.
Tubing is generally sized by the OD and the will thickness is lighter in weight
e) T
f) T
What does the term schedule refer to as it relates to pipe?
a) the pipe wall thickness
b) the weight per linear measure
c) avail lengths from suppliers
d) max pressure the pipe can withstand
a) the pipe wall thickness
Define the following positions and welds on pipe
a) 1G
b) 2G
c) 5G
a) also called 1GR
Groove weld in the flat position from above the joint while rotating the pipe with its axis horizontal.
b) 2G - Groove weld in the horizontal position with the pip axis fixed vertically - no pipe rotation
c) 5G - Groove weld completed with the pipe fixed horizontally. - no pipe rotation
- can be uphill or downhill
Single Vee preparations on pipe generally have an included angle within the range of
a) 22.5° - 30°
b) 30° - 45°
c) 45° - 60°
d) 60° - 75°
d) 60° - 75°
What root gap is recommended for a GMAW roll welded pipe joint prior to tack welding
a) 1/16” - 3/32”
b) 3/32” - 1/8”
c) 1/8” - 5/32”
d) 5/32” - 1/4”
c) 1/8” - 5/32”
Do all tack welds become an integral part of the weld? Explain
No, bridge tacks must be removed as the weld progresses
Tacks in the root must be fully penetrated and feathered to insure full fusion
Where should the 4 tacks be located on a 6” pipe to be welded in th 5G position
12,3,6 & 9 o’clock positions
What is the max length of tack welds used for joining 6” sch 80 pipe?
a) 1/4”
b) 1/2”
c) 3/4”
d) 1”
c) 3/4”
If a pipe fit up has a gap that is not uniform, at what location should the widest portion of the gap be placed in prep for welding?
a) at or near the narrowest of the gap
b) at or near the widest of the gap
c) at or near the first quarter of the joint
d) at or near the last quarter of the joint
d) at or near the last quarter of the joint
On a 3” sch 40 pipe what is the min # and length of tacks required
a) 2 tacks at 1” long
b) 2 tacks at 1/2” long
c) 3 tacks at 3/4” long
d) 4 tacks at 1” long
c) 3 tacks at 3/4” long
Draw a sketch of a 6” pipe indicating the location of 4 tacks.
Number them in order of completion.
4 tacks @ 12, 3, 6 & 9
in the following order 12,6,3,4
For an open gap root pass, using the following electrode B-G 49A 5C G6 (ER70S-6) the wire is being deposited using what method?
a) short circuiting
b) spray
c) globular
d) rotating arc metal transfer
a) short circuiting
The recommended gun angle and inclination for a GMAW 1G pipe joint is
a) 90° angle & 15° backhand
b) 45° angle & 15° forehand
c) 30° angle & 30° backhand
d) 60° angle & 30° forehand
a) 90° angle & 15° backhand
What mode of metal transfer is recommended for FCAW wire on the fill passes and cap in 2G position?
a) short circuiting
b) globular
c) pulsed spray
d) rotating arc metal transfer
b) globular
The root pass is becoming extensively heavy as you are welding a pipe in the 1G position. What corrective action would you take while welding
a) work closer to 12 o’clock position
b) work closer to the vertical position progressing downhill
c) slow the travel speed across the centre of the weld
d) incline the electrode more into the direction of travel
b) work closer to the vertical position progressing downhill
State 2 corrective actions that may help prevent the root pass from becoming concave with shrinkage marks showing on the inside?
a)
b)
Any of the following are correct
- Decrease wire feed speed and voltage
- work closer to the top near the 1oclock position
- reduce root spacing
- use a small root face rather than a feathered root edge
What is the recommended root opening for a 3” or larger pipe welded in GMAW in the 5G position?
a) 1/16” - 3/32”
b) 3/32” - 1/8”
c) 1/8” - 5/32”
d) 5/32” - 1/4”
c) 1/8” - 5/32”
The preferred direction of travel for GMAW on the root pass in the 5G position
a) uphill
b) downhill
c) backhand
d) forehand
b) downhill
Is it possible to weld the below situation in the opposite direction?
- 5G root pass downhill
Yes a 5G root can be done in uphill or down hill directions
Cleaning the root pass prior to the second pass with FCAW is
a) never required
b) required only if weave beads are done
c) required only if stringer beads are done
d) required if large islands of non metallic oxides are present
d) required if large islands of non metallic oxides are present
With GMAW the pipe is placed into the 2G position. the position is ______ and there is ____ ______ of the pipe once the welding begins.
a) stationary, no rotation
b) fixed, no rotation
c) stationary, is rotation
d) free, is rotation
b) fixed, no rotation
What is the schedule when referring to pipe?
a) when the pipe will be installed
b) how the pipe is to be installed
c) the pipe wall thickness
d) the pipes total thickness
c) the pipe wall thickness
What does NPS stand for?
Nominal Pipe Size
for pipe 1/8” to 12” the NPS is the aprox ID of a standard schedule wall thickness pipe.
≥14” NPS is the OD
1/8” - 10” = STD/Sch 40
12” = STD only
The wall thickness is identified by the weight of pipe and is referred to as the ____
a) OD
b) schedule of pipe
c) ID
d) NPS
b) schedule of pipe
How is tubing sized?
a) OD diameter
b) ID diameter
c) schedule
d) NPS
a) OD diameter
& the wall thickness is generally lighter in weight than pipe
Variations in weight and wall thickness have an effect only on the ____?
a) density
b) schedule
c) OD
d) ID
d) ID
for metric requirements a conversion factor of _______mm is used.
a) 25mm
b) 25.4mm
c) 25.7mm
d) 25.9mm
b) 25.4mm
a 30° to 37.5° bevel is normally used on pipe. This results in an included angle of 60° to ____ °
a) 65°
b) 70°
c) 75°
d) 80°
c) 75°
Using an L shaped jig to help align coupons for tacking may align the
______ however may not give good alignment of the _______ as there is a 12% tolerance in wall thickness for manufacturers.
a) inner walls, outer surfaces
b) outer surfaces, inner walls
c) using an L shaped Jig is not good practice for testing, stack coupons vertically instead
d) both b&c
d) both b&c
L shaped jigs may align the outside surfaces but due to 12% manufacturers tolerances it may not align the inner walls.
Better practice is to stack vertically and align the inside surfaces
what root space is required when fitting up pipe?
a) 1/16” - 1/8”
b) 1/8” - 5/32”
c) 5/32” - 8/32”
d) none of the above
b) 1/8” - 5/32”
After putting your spacer in when prepping pipe align
a) the outside wall
b) the inside wall
c) the schedule
d) none of the above
b) the inside wall
Rotate the pipe and tack the ______ to use weld metal shrinkage to equalize the gap
a) the narrower gap
b) the wider gap
c) 12 o’clock position
d) 9 o’clock position
b) the wider gap
For a 2G pipe weld what direction do you weld?
a) from the widest gap to the narrowest
b) from the narrowest gap to the widest
c) from the 12 o’clock position to the 3 o’clock position
d) from the 9 o’clock position to the 12 o’clock position
b) from the narrowest gap to the widest
True or False
Bridge tacks are only temporary and are used as spacers
True
What weave do you use on a 2G pipe root weld
a) crescent
b) circles
c) sawtooth weave
d) trapezoid
c) sawtooth weave
When staching horizontal welds, always start at the _____ and layer _____
a) top and work your way down
b) bottom and work your way up
c) stagger back and forth
d) it doesn’t matter which way you start
b) bottom and work your way up
it prevents metal from rolling down and causing overlap or lack of fusion
Welding a single Vee butt joint on pipe in the 1G (rotated) position. This is often called the _____ pipe weld.
a) 1GF
b) 1GR
c) 2GF
d) 2GF
b) 1GR
