Environmental Engineering Reference
In-Depth Information
a)
a)
Defect size, mm
b)
5.31
Detection of incomplete fusion and cracks (a), pores and slag
inclusions (b) by different methods: 1) ultrasound, 2) radiographic,
3) magnetic powder.
a)
b)
5.32
Total detectability
W
S
(
x
) of defects of various sizes in
butt 40 mm thick by different methods: a) ultrasonic,
W
S
(
x
) =
1-exp[-0.17(
x
-9)] b) gamma inspection,
W
S
(
x
) = 1 - exp [-0.12 (
x
-6)].
results were obtained in the Surguttruboprovodstroy Trust in inspection of
welded joints of pipelines with a diameter of 820-1020 mm.
The best results obtained in US inspection as compared with RG
inspection were also reported in Ref. 75 (Fig. 5.34).
Table 5.7 shows the results of a study to assess the relative information
content of different methods of testing welded joints in pipelines with a
diameter of 50-500 mm with a wall thickness of 3-10 mm. After inspection
(more than 1000 joints) the weld metal was machined layer by layer and
all defects were measured.
87
Table 5.6 shows that radiographic provides
greater accuracy for bulk defects (90%), and the ultrasonic method - for
Search WWH ::
Custom Search