ASME B31 G Level 1 Evaluation
Value
Material
D: Specified outside diameter of the pipe
Data Imput
t Pipe wall thickness
Unit
Carbon Steel
323.9
mm
10.3
mm
d: Defect Depth
5
mm
L: Defect Length
100
mm
70.000
°C
Design Temperature
Maximum Operating Temperature
MAOP: Maximum Allowable Operating Pressure (Design Pressure)
56
°C
87.4
Bars
MOP: Maximum Operating Pressure
Pt: Hydrostatic test pressure
PO: Operating pressure, may equal MAOP or MOP
SMYS: specified minimum yield strength at ambient conditions
Modified ASME B31G Method
Original ASME B31G Method
* An area of corrosion with maximum depth greater than 20%
but less than or equal to 80% of the wall thickness shall be
d/t permitted to remain in the pipeline unrepaired provided
that the pressure at such an area does not exceed a safe
level.
Sflow: Flow stress, defined in para. ASME B31G 2.2 (a) =1.1*SMYS
M=
Z:
SF:
SO:
SF*SO
2.997
1.510 safety factor =Pt/MAOP (But usually not less than 1.25)
1374.217 hoop stress at the operating pressure
2075.476
Bars
132
Bars
87.4
Bars
Bar
483
(1Mpa=10 Bar)
As per ASME B31.4
451.6.2.2:
48.54%
5313.000
Bars
ASME B31 G Assessement to be used
The flaw is acceptable where SF is equal to or greater than SF* SO, or where PF is equal to or greater than
Output Message
1.843
PS
For Z<=20
The flaw is Acceptable
45378.617 Safe operating pressure
For Z>20
SF Estimated failure stress level
Sflow: Flow stress, defined in para. ASME B31G 2.2 (a) =1.1*SMYS
4358.831
Bars
5313.000
Bars
Z<=50,
M=
1.688
Z>50, M=
3.096
SF
4130.103
Output Message
Bars
A Level 1 evaluation is a simple calculation that relies on single measurements of the maximum depth and axial extent of metal loss.
PS
The flaw is Acceptable
42997.394 Safe operating pressure
SF*SO
Sflow ASME B31G 1.7 (b)
Material
SMYS
Carbon Steel
Temperature
T<250°F (120°C)
Carbon
Steel and
low alloy
Steel
SMYS < 70 kpsi (483 Mpa)
Carbon
Steel and
low alloy
Steel
SMYS < 80 kpsi (551 Mpa)
T<250°F (120°C)
Sflow ASME B31G 1.7 (b)
Flow Stress
Sflow= = 1.1 X SMYS
, Sflow< SMTS
Sflow= = SMYS + 10 (KPSI), 69 Mpa
, Sflow< SMTS
Sflow= =(SUT+SYT)/2 , SUT & SYTare specified at
theoperating temperature (YT is the yield strength and UT is the
ultimate strength in tension)
l2
t
0
0
1
1
2
4
3
9
4
16
5
25
6
36
7
49
t
120
100
80
60
40
20
0
1
2
3
4
5
6
7
8
8
64
9
81
10
100
t
t
6
7
8
9
10
11