GF Piping Systems ECOS 160, Instruction Manual, Page: 28 / 148

9 Failure analysis Operating instructions ECOS 160/250/315
24
Feature Description Evaluation group
I II III
External state of joint
Welding flash too wide or too
narrow over part or all of weld
length, caused by, for example:
•
incorrect warming-up
time
• incorrect heating-
element temperature
• incorrect joint pressure
See pg.14
DVS 2202-1
guidelines See pg.14
DVS 2202-1
guidelines See pg.14
DVS 2202-1
guidelines
Non angular joint plane, leading
to variations in form of welding
flash over part or all of weld
length, cased by, for example:
•
edge preparation faults
•
incorrect welding unit
Permissible
if
b1≥ 0,7 x b2
Permissible
if
b1≥ 0,6 x b2
Permissible
if
b1≥ 0,5 x b2
Feature Description Evaluation group
I II III
Internal state of joint
No fusion or incomplete fusion
on joint faces, over part or the
whole of weld cross-section
caused by, for example:
• contaminated joint
faces
• oxidized joint faces
•
excessive reversal time
•
heating element
temperature too low
•
heating element
temperature too high
Not
Permissible Not
Permissible Not
Permissible
Hollow space in joint planes
caused by, for example:
•
Insufficient joint
pressure
•
Insufficient cooling
time
Not
Permissible Not
Permissible Not
Permissible
Isolated, numerously dispersed
or locally concentrated pores or
inclusions caused by, for
example:
• Vapour formation
during welding
•
Contaminated heating
element
Permissible
if
∆ s ≤ 0.05 x s
Permissible
if
∆ s ≤ 0.10 x s
Permissible
if
∆ s ≤ 0.15 x s