Works: Plot No. 4,5 & 46C, Akshar Industrial Park, At Moraiya, Ahmedabad - 382213, Gujarat, India — +91 92279 94511
Fabrication Services — Vessel Fabrication

LPG Storage Tank

Spherical and bullet-type pressure vessels engineered to store LPG, LNG, and NGL products safely under pressure — fabricated to ASME Section VIII and NFPA 58/59 with redundant relief protection.

Overview

Keeping a liquefied gas liquid until it's needed

An LPG storage tank holds propane, LNG, or NGL products in liquid form under enough pressure to keep them from vaporizing at ambient temperature. Unlike an atmospheric storage tank, it's a full pressure vessel — the design pressure is set by the equilibrium vapor pressure of the stored product at its maximum design temperature, not by an arbitrary safety margin. Get that number wrong and either the tank is underdesigned for a hot day, or overbuilt and needlessly expensive.

Fintelius selects spherical or bullet (horizontal cylindrical) geometry against the storage volume and site constraints, then engineers the shell, supports, and dual relief-valve system to NFPA equilibrium-pressure criteria and ASME Code, whether the tank ships aboveground, mounded, or for underground installation.

  • Spherical tanks for large-volume storage above roughly 500 m³; bullet tanks for smaller and mid-range volumes
  • Aboveground, mounded, and underground installation configurations
  • Stainless steel, Hastelloy, Monel, Inconel & Duplex 2205 construction options
  • Fabricated to ASME Section VIII Div. I & II and NFPA 58, with dual 100%-capacity relief valves
LPG storage tank — shop fabrication
How It Works

From equilibrium pressure calculation to a hydrostatically tested tank

Every LPG tank follows the same disciplined path through design and fabrication.

1

Design Pressure & Temperature Analysis

Stored product's equilibrium vapor pressure at maximum design temperature (ambient plus solar radiation) sets the governing design pressure.

2

Geometry & Installation Selection

Spherical or bullet geometry, and aboveground, mounded, or underground installation, are selected against volume and site constraints.

3

Shell & Head Fabrication

Plate is rolled and formed to the design diameter and wall thickness, welded to spherical or cylindrical shell geometry.

4

Welding, NDE & PWHT

All welds are radiographed and ultrasonically tested; thick sections undergo post-weld heat treatment per code.

5

Hydrostatic Testing & Dispatch

The complete tank is hydrostatically tested, coated, and prepared for shipment or field erection with full documentation.

Tank Configurations

Matched to storage volume & site layout

SP

Spherical Tank

The most economical shell geometry for storage volumes above roughly 500 m³ — a sphere minimizes shell surface area, and therefore material and cost, for a given volume under pressure.

BT

Bullet (Horizontal Cylindrical) Tank

Typically used under 100 m³ and common in the 100–500 m³ range where total weight and installation logistics favor a cylindrical shape over a sphere.

UG

Underground / Mounded Tank

Horizontal configuration by default regardless of capacity — buried or mounded on a concrete platform for space-limited or safety-driven site layouts.

Design & Safety Considerations

What separates a safe LPG tank from an underdesigned one

These parameters are set by code and equilibrium physics, not estimated.

01

Equilibrium Design Pressure

Design pressure is set to the stored product's equilibrium vapor pressure at maximum design temperature — per NFPA, roughly 41°C (underground), 46°C (>4.5 m³), or 54°C (≤4.5 m³).

02

Dual 100% Relief Valves

Two pressure relief valves, each rated to 100% capacity, are mandated so one can be serviced or isolated without taking the tank out of service.

03

Excess Flow & Safety Valves

Excess-flow check valves limit release rate in the event of downstream piping failure, working alongside the primary relief system.

04

Gas Leak Detection

Integrated leak-detection instrumentation for early warning ahead of a release reaching hazardous concentration.

05

Heating & Cooling Systems

Optional temperature-control systems maintain product state and pressure within design limits across ambient extremes.

06

Welded Support Design

Legs, lugs, skirts, or saddles engineered for the tank's geometry, seismic zone, and foundation type.

Core Equipment & Mechanical Design

What a pressurized liquefied-gas vessel demands

01

Shell & Head Fabrication

Rolled shell and formed heads (or welded spherical segments) to the design diameter and wall thickness.

02

Nozzle & Manway Fabrication

Fill, withdrawal, vapor equalization, relief, drain, and instrumentation nozzles with reinforcement pads; manways for internal access.

03

Support Structure Fabrication

Legs, lugs, skirts, or saddles fabricated and welded to the vessel per site foundation and orientation requirements.

04

Advanced Coating Systems

Protective coating options for above-ground weathering resistance and, where specified, corrosion protection for buried installations.

05

Post-Weld Heat Treatment

Stress-relief heat treatment for thick-walled shell and head sections per ASME code requirements.

06

Radiography & Ultrasonic NDE

Weld integrity verification across all shell, head, and nozzle welds before hydrostatic test.

07

Hydrostatic Test Rigs

Full-vessel pressure testing to design specification prior to dispatch.

08

Instrumentation Integration

Level, pressure, and temperature instrumentation supporting safe operation and inventory management.

09

NFPA 58 Code Compliance

Fabrication and safety features engineered to the NFPA 58 stationary LPG storage code alongside ASME pressure vessel requirements.

Design Specifications

Capability at a glance

Configurations
Spherical & bullet (horizontal cylindrical)
Installation Types
Aboveground, mounded & underground
Governing Codes
ASME Section VIII Div. I & II, NFPA 58 / 59, API 2510
Quality System
ISO 9001:2015 certified fabrication
Products Stored
LPG (propane), LNG (methane), NGL (ethane, propane, butane, pentane, isobutane)
Materials
Stainless steel, Hastelloy, Monel, Inconel & Duplex 2205
Capacity
Up to 25,000 gallons
Weight Capacity
Up to 100 tons
Spherical Threshold
Generally preferred above ~500 m³
Bullet Threshold
Generally preferred under ~100 m³
Relief Protection
Dual pressure relief valves, each rated 100% capacity
Testing
Radiography, ultrasonic testing & full hydrostatic test
Applications

Where our LPG storage tanks go to work

OG

Oil & Gas Production

Bulk LPG and NGL storage at production, gathering, and processing facilities.

PC

Petrochemical & Chemical Processing

Feedstock and product storage for downstream petrochemical and chemical manufacturing operations.

PG

Power Generation

Fuel storage supporting LPG and NGL-fired power generation facilities.

MR

Marine & Terminal Storage

Bulk storage supporting marine terminal loading, unloading, and distribution operations.

DS

Distribution & Bottling

Bulk storage feeding downstream cylinder-filling and distribution operations.

IR

Industrial & Residential Bulk Supply

Aboveground and underground tanks serving industrial facilities and residential bulk propane supply.

Need an LPG storage tank sized for your site and product?

Send us your product, required volume, and installation constraints for a fabrication proposal.

Request a Proposal