Thickness compliance
t_nom at or above t_min, and MAOP at or above design pressure
COMPLIANT
Selected 9.50 mm nominal wall is at or above t_min and supports 10,816 kPa.
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Pipeline Wall Thickness Sizing
Size minimum required wall and check the selected nominal thickness against design pressure. Defaults are a 508 mm, Grade 483, 9.5 mm WT metric example under ASME B31.4 (F=0.72) with E=1.00 and T=1.00. Switch to US Customary to convert those inputs. Results update as you edit.
Section 1
Units & Design Code
Unit system
Switching units converts the numbers already in the form. E and T stay the same.
Sets the primary-panel design factor F to 0.72. The comparison grid still shows every encoded class.
Section 2
Pipe & Design Parameters
mm
MPa
kPa
mm
mm
factor
1.00 for Seamless / ERW. Use a lower value for EFW or lap weld.
factor
T stays 1.00 at or below 121 °C per B31.4 / B31.8. This tool does not apply a full temperature table.
Section 3
Wall Thickness & MAOP
Design factor F
0.72
From the selected primary design code and location class
Allowable hoop stress S
347.76 MPa
S = F x SMYS
Pressure design thickness t_p
7.25 mm
t_p = (P x D) / (2 x S x E x T)
Min required wall t_min
8.85 mm
t_min = t_p + corrosion allowance
Design pressure capacity (MAOP)
10,816 kPa
MAOP = 2 x (t_nom - A) x S x E x T / D
D/t slenderness
53.5 nom / 57.4 min
Limit is D/t of 140 or less for both checks
Slenderness D/t
D/t_nom and D/t_min at or below 140
PASS
D/t_nom is 53.5 (PASS). D/t_min is 57.4 (PASS).
Section 4
Multi-standard comparison
Side-by-side encoded design-factor checks for the same inputs. The primary code still drives the results panel above. Scroll sideways on a narrow screen.
| Code / class | F | t_min (mm) | MAOP (kPa) | Thickness | D/t_min |
|---|---|---|---|---|---|
| ASME B31.4 liquidPrimary | 0.72 | 8.85 | 10,816 | COMPLIANT | 57.4 PASS |
| ASME B31.8 Class 1 Div 1 | 0.80 | 8.13 | 12,018 | COMPLIANT | 62.5 PASS |
| ASME B31.8 Class 1 Div 2 | 0.72 | 8.85 | 10,816 | COMPLIANT | 57.4 PASS |
| ASME B31.8 Class 2 | 0.60 | 10.30 | 9,013 | UNDERSIZED | 49.3 PASS |
| ASME B31.8 Class 3 | 0.50 | 12.04 | 7,511 | UNDERSIZED | 42.2 PASS |
| ASME B31.8 Class 4 | 0.40 | 14.65 | 6,009 | UNDERSIZED | 34.7 PASS |
| CSA Z662 Class 1 | 0.80 | 8.13 | 12,018 | COMPLIANT | 62.5 PASS |
What this tool calculates
Allowable hoop stress is S = F times SMYS. Pressure design thickness is t_p = (P x D) / (2 x S x E x T). Minimum wall is t_min = t_p plus the corrosion allowance. MAOP is 2 x (t_nom - A) x S x E x T / D. The thickness gate is COMPLIANT when t_nom is at or above t_min and MAOP is at or above design pressure. Otherwise it is UNDERSIZED.
Slenderness checks are D/t_nom and D/t_min. Either ratio above 140 fails that check. The comparison grid repeats the same OD, SMYS, design pressure, corrosion allowance, nominal wall, E, and T across every encoded location class. The primary code selector still drives the main results panel.
Metric uses mm, kPa, and MPa, with SMYS converted from MPa to kPa inside the hoop-stress term. US Customary uses inches and PSI, including SMYS in PSI. Switching the unit toggle converts values already in the form: length and thickness by 25.4, SMYS by 145.038, and pressure by 0.145038. E and T are dimensionless and do not convert.
Design factors encoded here: ASME B31.4 liquid and ASME B31.8 Class 1 Div 2 use 0.72. ASME B31.8 Class 1 Div 1 and CSA Z662 Class 1 use 0.80. ASME B31.8 Class 2 uses 0.60, Class 3 uses 0.50, and Class 4 uses 0.40. Default E is 1.00 for Seamless / ERW. Default T is 1.00 at or below 121 °C / 250 °F. The grid is encoded design-factor checks only. These are the numeric checks in this tool, not a full code review.