Category
Pressure Vessels & Reactors
Subcategory
Pressure Vessel
Applicable standards
3
Issuing bodies
3
Description
British pressure vessel code — alternative to ASME VIII Div 1 for UK / Commonwealth markets.
Applicable Standards (3)
ASME — 1 standard
ASME BPVC Sec VIII Div 1
Rules for Construction of Pressure Vessels
Mandatory rules for design, fabrication, inspection, testing and certification of pressure vessels operating above 15 psig (~1 barg).
Key requirements (12)
- Applies to vessels with internal pressure > 15 psig (1.03 barg) up to ~3000 psi (Div 1 sweet spot).
- Joint efficiency E: 1.0 (full radiography), 0.85 (spot RT), 0.70 (no RT) for Type 1 butt joints.
- Shell thickness: t = P·R/(S·E – 0.6·P) for circumferential stress (UG-27).
- Head thickness: t = P·D/(2·S·E – 0.2·P) for 2:1 ellipsoidal heads (UG-32).
- Hydrostatic test pressure: 1.3 × MAWP × (S_test/S_design) — UG-99.
- Pneumatic test (when hydro impractical): 1.1 × MAWP — UG-100.
- Corrosion allowance is added to calculated thickness (not included in S formula).
- MDMT and impact testing per UCS-66 / Figure UCS-66; below the curve, Charpy V-notch impacts are required.
- PWHT thresholds per UCS-56 — generally required above 19 mm thickness for P-No. 1 carbon steels.
- Nozzle reinforcement: area replacement method (UG-37) within reinforcement zone.
- Maximum allowable stress S: from ASME II Part D, Table 1A/1B/3 — temperature dependent.
- Flanges per ASME VIII-1 Appendix 2 (or B16.5 for standard sizes).
Note: Most widely used pressure vessel code worldwide.
EN/CEN — 1 standard
EN 13445
Unfired pressure vessels
Default European pressure vessel code (alternative to ASME VIII).
Key requirements (8)
- European unfired pressure vessel standard, harmonized with PED 2014/68/EU.
- Parts: 1 General, 2 Materials, 3 Design, 4 Fabrication, 5 Inspection, 6 Cast Iron, 8 Aluminum.
- Two design routes: Design by Formulas (DBF) and Design by Analysis (DBA).
- Testing groups 1–4 with progressively reduced NDE for Group 4 (lower duty).
- Hydrostatic test: 1.25 × max allowable pressure × (f_test/f_design).
- Joint coefficient z replaces ASME's joint efficiency E (1.0 / 0.85 / 0.7).
- Material grouping per CR ISO 15608 (P-numbers in ASME parlance).
- PED conformity assessment Module H or G typical for Cat IV vessels.
BSI — 1 standard
PD 5500
Specification for unfired fusion welded pressure vessels
British pressure vessel code (formerly BS 5500); often used in Commonwealth countries.
Key requirements (7)
- British Standard for unfired fusion-welded pressure vessels (Cat 1 / Cat 2 / Cat 3).
- Cat 1 = full RT, Cat 2 = partial RT, Cat 3 = visual + limited NDT.
- Design factor f = lower of UTS/2.35 and Yield/1.5 at design temperature.
- Hydrotest: 1.25 × design pressure (Cat 1) or 1.5 × design pressure (Cat 2/3).
- Annex D: design by analysis (FEA) — alternative to formula-based design.
- Annex G: vessel-on-saddle stress analysis (Zick analysis).
- Used widely in UK, Middle East, India for non-nuclear vessels.