An LPG spherical tank (also called an LPG storage sphere or Horton sphere) is designed to store large volumes of pressurized liquefied petroleum gas (LPG)—typically propane, butane, or mixed LPG—safely and efficiently. Its spherical shape distributes internal pressure evenly, which helps reduce stress concentration, improves structural stability, and can make it a preferred choice for medium-to-large LPG terminals, refineries, petrochemical plants, and gas distribution hubs.

What is a spherical tank used for?

The main purpose of a spherical tank is high-capacity, pressurized storage of products that:

• are stored as liquids under pressure (like LPG)

• may experience pressure changes with ambient temperature

• require robust containment with strong safety design

Common stored media include:

• Propane

• Butane

• LPG mixes

• In some cases, other pressurized liquefied gases (site- and code-dependent)

Why choose a spherical design for LPG storage?

1) More uniform stress under pressure

A sphere is the geometry that naturally handles internal pressure efficiently. Compared with many other shapes, it provides:

• Even distribution of membrane stress

• Reduced risk of high-stress “corners” or edges

• A structure well-suited for high pressure + large volume storage

2) Material efficiency at scale

For the same internal volume, a sphere can require less surface area than many alternatives—meaning:

• Potentially lower heat gain from the environment (helpful for product stability)

• Often good strength-to-weight efficiency for very large tanks

3) Long service life in harsh industrial conditions

When designed and maintained properly, LPG spherical tanks are used in demanding environments and can support:

• long-term cyclic service (pressure/temperature changes)

• industrial safety management requirements

• integration into terminals and processing facilities

Where you typically see LPG spherical tanks

An LPG spherical tank is commonly installed at:

• LPG import/export terminals

• Refineries

• Petrochemical plants

• Gas fractionation and processing facilities

• City gas / LPG bottling & distribution depots

• Strategic storage farms for peak shaving and supply security

How an LPG spherical tank supports operations

Stable supply and logistics flexibility

Large-volume spherical storage helps operators:

• receive shipments in bulk (ship/rail/truck)

• buffer demand fluctuations

• reduce frequent deliveries and handling

• optimize downstream distribution to cylinder filling plants or pipeline networks

Controlled product handling

A typical sphere system is integrated with:

• transfer pumps/compressors

• vapor return / balancing lines

• loading arms or truck/rail gantries

• instrumentation for pressure/temperature/level

• ESD (Emergency Shut Down) systems and safety interlocks

Key safety and design features (high level)

Because LPG is flammable and stored under pressure, spherical tanks are engineered with multi-layer protection, often including:

• Safety relief valves sized for credible scenarios

• Level measurement (often redundant) to prevent overfill

• Pressure and temperature instrumentation

• Fire protection measures (water spray/monitors, fireproofing—site dependent)

• Gas detection and emergency shutdown integration

• Dikes/drainage and spacing per applicable codes and risk assessment

• NDT and inspection planning for weld integrity and lifecycle management

Exact configuration depends on local regulations, project standards, and hazard studies (HAZOP/QRA).

Spherical tank vs bullet tank: what’s the difference?

Both are used for pressurized LPG storage, but they fit different project scales.

LPG spherical tank

Best for:

• larger capacity storage (terminal/plant level)

• long-term strategic buffering

• centralized distribution hubs

Typical advantages:

• strong pressure performance at large volumes

• efficient geometry for high-capacity installations

LPG bullet tank (horizontal cylindrical)

Best for:

• small to mid-size depots

• industrial users with moderate storage needs

• sites where simpler installation is preferred

Typical advantages:

• easier fabrication/transport for smaller sizes

• flexible siting in many facilities

In practice, many LPG storage farms use a mix based on capacity, plot plan, and logistics.

What to consider when specifying an LPG spherical tank

When people search “lpg spherical tank”, they’re usually planning a project or checking feasibility. These are the inputs that matter most:

1. Storage capacity & number of spheres
   Total working volume, future expansion plans, and peak demand buffer.

2. Design pressure & design temperature
   Based on LPG composition, ambient extremes, and operating philosophy.

3. Applicable codes and certifications
   Project location often dictates the design code, inspection rules, and documentation.

4. Seismic and wind requirements
   Critical for structural design and foundation engineering.

5. Safety philosophy & automation level
   Redundancy, SIS/ESD integration, firefighting strategy, and monitoring.

6. Construction approach & schedule constraints
   Onsite fabrication vs modularized components; lifting plans; logistics.

7. Operations: loading/unloading and product turnover
   Ship/rail/truck interfaces, vapor return, metering, and custody transfer needs.

Typical lifecycle: from engineering to commissioning

A spherical tank project usually involves:

• FEED / basic engineering (capacity, plot plan, standards)

• Detailed design (mechanical, civil, piping, instrumentation)

• Fabrication and NDT

• Site erection and welding

• Pressure testing and commissioning

• Long-term inspection and integrity management

For EPC and terminal owners, vendor capability in engineering coordination, quality control, and project documentation is often as important as fabrication itself.

How CIMC ENRIC fits into LPG spherical tank projects

If you’re developing an LPG storage facility, it helps to work with a supplier who can support not just the vessel, but also the project interface—drawings, quality documentation, and delivery coordination.

CIMC ENRIC supports a range of gas storage and transportation equipment solutions. In LPG terminal or depot projects, we can provide practical input on:

• capacity configuration (single vs multiple spheres)

• project documentation alignment

• manufacturing and inspection requirements

• integration considerations for terminal operations

FAQ

Q: Why are LPG tanks sometimes spherical?

A: Because a sphere handles internal pressure efficiently by distributing stress evenly, which suits large-volume pressurized storage.

Q: What gases can be stored in a spherical tank?

A: Most commonly LPG (propane, butane, mixes). Other pressurized liquefied gases may be possible depending on design code and project requirements.

Q: Are spherical tanks safer than bullet tanks?

A: Safety depends on design, installation, protection systems, and operations. Spheres are often chosen for large capacities and can be very robust, but both types can be safe when properly engineered and managed.

Q: How do I choose between a sphere and a bullet tank?

A: Start with capacity needs, plot plan constraints, standards, and logistics (how you receive and distribute LPG). Large terminal-scale storage often favors spheres.