GMAW FCAW and MCAW on mild steel pipe

Question 1

What are the three important dimensions for pipe?

Answer 1

A) outside diameter

b) inside diameter
c) wall thickness

Question 2

Are the following statements regarding pipe true or false?

a) OD is identically to the nominal size for all pipe
b) nominal size is the approximate ID of standard wall pipe
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 its schedule
f) Pipe 350 mm and larger is identified by OD

Answer 2

a) false
b) true
c) true
d) false
e) true
f) true

Question 3

What does the term schedule refer to as it relates to pipe?

a) the pipe wall thickness
b) the weight per linear measure
c) available lengths from suppliers
d) maximum pressure the pipe can withstand

Answer 3

a) the pipe wall thickness

Question 4

Define the following positions and welds on pipe:

a) 1G
b) 2G
c) 5G

Answer 4

a) weld completed in a flat position from above the joint while rotating the pipe with its axis horizontal. 1GR
b) 2G is the groove weld completed in the horizontal position with the pipe axis fixed vertically. no rotation.
c) 5G is a groove weld completed with the pile axis fixed horizontally. There is no rotation and progression may be uphill or downhill.

Question 5

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

Answer 5

d) 60 - 75

Question 6

What root gap is recommended for GMAW roll welded pipe joint prior to tack welding?

a) 1.6mm - 2.5mm
b) 2.5mm - 3.2mm
c) 3.2mm - 4mm
d) 4mm.- 6.4mm

Answer 6

c) 3.2mm - 4mm

Question 7

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 preparation for welding?

Answer 7

The widest gap should be placed at or near the last quarter of the joint to be welded.

Question 8

For an open gap root pass, a B-G 49A 5 C G^ (ER70S-6) wire is deposited using:

a) short-circuiting arc metal transfer
b) spray arc metal transfer
c) globular arc metal transfer
d) rotating arc metal transfer

Answer 8

a) short-circuiting arc metal transfer

Question 9

What mode of metal transfer is recommended for FCAW wire on the fill passes and cap in the 2G position?

a) short-circuting
b) globular
c) pulsed spray
d) rotating arc modulated pulsed spray

Answer 9

b)globular

Question 10

State two corrective actions that may help prevent the root pass from becoming concave with shrinkage marks showing on the inside.

Answer 10

a) decrease wire feed speed and voltage
b) work closer to the top near the 1 o’clock position
c) reduce the root spacing
d) use a small root face rather than a feathered root edge

Question 11

The preferred direction of travel for GMAW on the root pass in the 5G position is ____

Answer 11

downhill

Question 12

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 stinger beads are done.
d) required if large islands of non-metallic oxides are present

Answer 12

d) required if large islands of non-metallic oxides are present