ATTACHMENT 1
Document No. 1902-01PL-30-02J-A0217
Wall Thickness Calculation for 4" Liquid Pipeline
From GGS Asap To LPP Nagote
DESIGN INPUT
References
Design Code
Pipeline Size / Nominal O.D
Corrosion Allowance
Location Class
Design Factor
Steel Coefficient of Expansion,
Modulus of Elasticity
Mill Tolerance
D
A
ASME B31.4
4.5
2.54
F
α
E
tol
0.72
0.0000117
2.03E+05
12.50%
Pressure and Temperature Input
Design Pressure
Installation/ Burial Temp. (UG)
Under Ground / MAX Design Temp.
P
T1u
T2u
19.7
25
49
32
T2u(min)
Minimum Design Temp.
Weld joint factor
Poison Ratio
Max. factor for load of long durations
Cold Bend Radius in term of Dia.
E
ν
k
Rbend
1
0.3
0.9
40D
Elastic Bend Radius in term of Dia.
R
500D
in
mm
114.3
mm
*Corrosion Resistance Alloy
per deg C
MPa
o
6.50E-06 in/in/ C
2.94E+07 Psi
bar g
C
C
o
C
285.0
77.0
120.0
90.0
o
o
Clause 402.2.1 of ASME B31.4
Clause 402.2.2 of ASME B31.4
psi g
F
F
o
F
o
o
Table 403.2.1-1 of ASME B31.4
Clause 402.2.3 of ASME B31.4
WALL THICKNESS
1
Grade
SMYS of Line Pipe
Wall Thickness Calculated
tmin = (P x D / (2x Sx Fx E) + A) / (1 - tol)
B
35000
3.19
6.54
6.02
18.99
102.26
8,212.99
S
tcal
tmin
Selected wall thickness
D/t Check ( Should be < 96)
Pipeline Internal Diameter ID = D -2t
Internal Area of Pipe Ai = p ID2/4
t
psi
mm
241
0.125
MPa
inch
mm
0.237
inch
Table 7 Clause 9.3.2 OF API 5L
Clause 403.2.1 of ASME B31.4
ASME B36.10M (sch. STD)
mm
mm2
Calculation - Hoop Stress (determined by Barlow's Formula)
2
Wall thickness (t-CA)
Hoop Stress = SH = PD/2(t-CA)
Hoop Stress <
0.72 E SMYS
3.48
32.27
13.37
OK
mm
-56.9
-17.13
9.68
0.00
67.80
MPa
MPa
MPa
MPa
MPa
Mpa
% of SMYS
Clause 402.3 of ASME 31.4
Table 403.3.1-1 of ASME B31.4
A. RESTRAINED PIPE (UNDER GROUND)
3a
3b
4
5
6
7a
SE1
SE2
Sp
Sx
SB
Thermal Stress due to expansion @T2u = SE1 = a (T1u - T2u) E
Thermal Stress due to expansion @T2u(min) = SE2 = a (T1u - T2u) E
Longitudinal Stress due to pressure = SP = ν SH
Longitudinal Stress due to axial loading pressure = Sx
Nominal Bending Stress = SB = ED/2R
Summation of Longitudinal Stress, SL
SL = SP + SE + SX + SB
≤ 0.9 x SMYS = 218 MPa
Net Longitudinal Stresses for Max. Design Temp. (T2u)
8
8a
SL11
20.60
MPa
SL12
-114.99
MPa
Longitudinal Stresses due to tensile bending
SL21 = SP + SE2 + SX + SB
SL21
60.35
MPa
Longitudinal Stresses due to compressive bending
SL22 = SP + SEE2+ SX - SB
Maximum Longitudinal Stress, SL
SL22
SL(max)
MPa
Permitted Value Longitudinal Stress
Longitudinal Stress check :
hence
-75.25
60.35
217.18
OK
Allowable Combined Stress = 0.9SMYS
Combined Stress, SE
Sc
217.18
Torsional Stress
Combined Biaxial Stress at Maximum Design Temperature
Combined Biaxial Stress at Tensial Bending
St
0.00
Seq11 = [ SH2 -SHSL11+ SL112 +3St2 ]1/2
Combined Biaxial Stress at Compressive Bending
Seq11
28.30
MPa
Seq12
134.07
MPa
Longitudinal Stresses due to compressive bending
SL12 = SP + SE1+ SX - SB
Net Longitudinal Stresses for Max. Design Temp. (T2u(min))
2
2
Seq11 = [ SH -SHSL12+ SL11 +3St2 ]1/2
SL ≤ 0.9 x SMYS
Clause 402.6.1 of ASME B31.4
Table 403.3.1-1 of ASME B31.4
Longitudinal Stresses due to tensile bending
SL11 = SP + SE1 + SX + SB
7b
Clause 402.5.1 of ASME B31.4
Page 1 of 2
Table-403.3.1-1 of ASME B31.4
Clause 402.7 of ASME B31.4
8b
Combined Biaxial Stress at Minimum Design Temperature
Combined Biaxial Stress at Tensial Bending
Seq11 = [ SH2 -SHSL21+ SL112 +3St2 ]1/2
Combined Biaxial Stress at Compressive Bending
Seq11
52.30
MPa
Seq11 = [ SH2 -SHSL22+ SL112 +3St2 ]1/2
Maximum Combined Biaxial Stress
Combined Stress check :
Seq12
Seq
95.56
134.07
OK
MPa
16.1
MPa
Mpa
Mpa
hence
SE ≤ 0.9 x SMYS
B. UNRESTRAINED PIPE (ABOVE GROUND)
9
10
11
12
13
14
Sp
SB
Sx
SL
SA
SB
SL
Longitudinal Stress due to pressure = SP = 0.5 SH
Nominal Bending Stress due to weight SB = M/ Z
Axial Stress other than due to thermal expansion and pressure
Net Longitudinal Stresses SL = SP +SB + SX
Permitted Longitudinal stress (0.75SMYS)
Allowable bending stress SB = 0.75ST - SP - SX
Summation of Longitudinal Stress, SL
Longitudinal Stress check :
SL ≤ 0.75 x SMYS
0.00
Clause 402.3 of ASME B31.4
Clause 402.6.2 of ASME B31.4
hence
180.99
164.85
180.99
OK
Tg
Lb = L - 2Tg
H
1.5
9
10
m
m
inch
B
3.18
deg
B
Rmax
1.50
84.88
35
52.50
deg
D
point
degree
Table 403.3.1-1of ASME B31.4
MAXIMUM BENDING ANGLE
15
16
17
18
Tangent length each pipe end, Tg
Length of cold bend, Lb
Minimum distance between point of bend, H
Angle degree at each point of bend Calculated for R=40D, B
maximum angle per each Bend shall not more than 1.5°
19
20
Total point to be bend, G
Maximum cold bending angle per joint (12m), Cbmax
G = Lb / H
Cbmax = B x G
PIPE WALL THINNING
21
22
23
Thinning Percentage
Thinning Nominal
Pipe wall thickness after bending
24
25
Selected Wall Thickness
Thickness required for bending
0.13 %
0.79 mm
5.229 mm
t
<
Selected Wall Thickness
6.02
OK
4" FIELD BEND SCHEME
Page 2 of 2
mm
0.031 inch
0.206 inch