Category
Cryogenic & Refrigerated Storage
Subcategory
LPG
Applicable standards
5
Issuing bodies
4
Description
Pressurized LPG storage bullet (cylindrical or spherical) — above ground or mounded.
Applicable Standards (5)
API — 1 standard
API 510
Pressure Vessel Inspection Code: In-service Inspection, Rating, Repair, and Alteration
In-service inspection, repair, alteration and re-rating of pressure vessels.
Key requirements (8)
- Applies to in-service pressure vessels covered originally by ASME VIII or other recognized code.
- Inspection intervals: external ≤ 5 years, internal ≤ 10 years OR ½ remaining life — whichever is less.
- On-stream UT inspection can replace internal at user's choice if conditions permit.
- Authorized Inspector (AI) certification required for inspection signoff (API ICP).
- Repair/alteration must follow original construction code; reratings allowed via re-calculation + hydrotest waiver if conditions met.
- RBI per API 580/581 may justify extended intervals beyond default limits.
- Damage mechanisms reference: API 571.
- Fitness-For-Service per API 579 when defects exceed acceptance limits.
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.
NFPA — 1 standard
NFPA 58
Liquefied Petroleum Gas Code
LP-Gas storage, handling, transport in the US.
BIS — 2 standards
IS 6044 (Parts 1 & 2)
Code of Practice for LPG Storage Installations
Indian LPG storage facilities — pressurized and refrigerated.
Key requirements (4)
- Indian code for LPG storage installations — Part 1 (above-ground pressurized) and Part 2 (refrigerated).
- Covers spacing, fire protection, vent stack height, instrumentation.
- Aligned with NFPA 58 in approach but with Indian PESO statutory framework.
- Mandatory deluge water spray, gas detection, automatic ROV on inlet/outlet lines.
IS 10987
Code of Practice for Design, Fabrication, Inspection and Testing of Underground / Mounded Welded Bullet Storage Tanks
Indian standard for underground / mounded LPG bullet tanks.