Engineered cryogenic storage tanks designed as part of cryogenic equipment systems for LNG, liquid nitrogen, oxygen, and argon—delivering maximum thermal efficiency, minimal boil-off, and long-term operational reliability.
Our vacuum-insulated cryogenic tanks are built for industrial gas, energy, and medical applications, ensuring safe storage and stable pressure control under extreme low-temperature conditions below −150°C.
What Are Cryogenic Liquid Storage Tanks?
Cryogenic storage tanks are double-walled, vacuum-insulated pressure vessels used for storing liquefied gases such as LNG, liquid nitrogen (LN₂), liquid oxygen (LOX), and liquid argon (LAr).
- Inner vessel: stainless steel for cryogenic compatibility
- Outer vessel: carbon steel for structural strength
- Interspace: high vacuum with perlite insulation
This design significantly reduces heat ingress, minimises boil-off gas (BOG), and maintains product purity during long-term storage and transport.
Main Components & Applications
Cryogenic storage systems typically include:
- Tank for liquid gas storage
- Pump to raise liquid pressure
- Tank Vaporiser to convert liquid to gas at ambient temperature
These systems are widely used for:
- Industrial gas backup solutions
- Storage of oxygen, nitrogen, argon, hydrogen, and other cryogenic gases
- Ensuring uninterrupted supply in manufacturing, healthcare, and laboratory applications
Types of Cryogenic Vacuum-Insulated Tanks
Cryogenic vacuum-insulated tanks are engineered for the safe storage and delivery of liquefied gases at extremely low temperatures. They are primarily classified into two types:
1. VIT (Vacuum-Insulated Tank)
- Designed for pressures up to 5 bar (g).
- Used for storage of liquid intended for delivery to a pump or tanker.
- Features a double-walled structure with vacuum insulation for minimal heat ingress.
2. VIE (Vacuum-Insulated Evaporator)
- Designed for pressures up to 35 bar (g).
- Operates with a vaporiser to supply gas directly to customers.
- Ideal for supplying large quantities of gas over a short period.
- Construction: inner vessel made of stainless steel, outer vessel of carbon steel.
- Insulation: vacuum interspace filled with perlite for excellent thermal performance.
- Often supplied with instrumentation such as level indicators and pressure protection devices.
Operational Safety
To ensure safe operation, a dedicated person should be responsible for regular inspection of the cryogenic liquid storage tank. Key checks include:
- Ensure the inner vessel pressure does not exceed the tank’s working pressure. If it does, take immediate pressure relief measures.
- Inspect all valves and fittings for leaks or abnormal conditions.
- Verify instrumentation is functioning correctly, including level indicators and pressure protection systems.
VIT vs VIE vs Flat-Bottom Tanks
| Type | Function | Pressure Range | Application |
|---|---|---|---|
| VIT | Liquid storage | Low pressure | Storage before pumping |
| VIE | Gas supply | Medium to high | Direct industrial gas supply |
| Flat-bottom | Bulk storage | Near atmospheric | LNG terminals & large plants |
Cryogenic Storage Tank Design – Flat-Bottom Tanks
- Atmospheric storage slightly above ambient pressure
- Designed for large quantities of a single product
- Inner vessel: stainless steel; Outer vessel: carbon steel
- Typically site-built with emergency flap valves on main inlets/outlets
- Insulation: perlite-filled interspace with nitrogen purge
Maintenance Recommendations:
- Regularly check the jacket vacuum. If it deteriorates, conduct additional vacuuming via a professional service or manufacturer
- Identify and correct equipment or accessory failures promptly to ensure safe and continuous operation
How to Choose the Right Cryogenic Tank
- Small demand (labs / medical): Dewars or small cryogenic cylinders
- Medium demand: VIE systems for continuous gas supply
- Large-scale storage: Flat-bottom LNG tanks
- Transport applications: ISO cryogenic tanks
Selecting the correct system depends on capacity, pressure requirements, and end-use application.
Capacity Range and Applications
- Small-scale: 50 – 500 L (laboratories, medical)
- Medium-scale: 1 – 50 m³ (industrial gas supply)
- Large-scale: 100 – 200,000 m³ (LNG storage)
Typical Applications:
- Industrial gas supply systems
- LNG storage and distribution
- Medical oxygen systems
- Food freezing and preservation
- Electronics and semiconductor manufacturing
Boil-Off Gas (BOG) Management
Advanced cryogenic tank systems are designed to minimise boil-off gas through:
- High-efficiency vacuum insulation
- Perlite or multilayer insulation systems
- Pressure control and recondensation systems
Effective BOG management reduces product loss and improves overall system efficiency.
Safety and Maintenance
- Continuous pressure and level monitoring
- Regular inspection of valves and pipelines
- Verification of pressure relief devices
- Vacuum performance monitoring
Maintenance:
- Periodic vacuum re-evacuation
- Leak detection and repair
- Compliance with international standards
Codes and Standards
Internationally recognized codes and standards regulate cryogenic storage tank design, manufacturing, and operation. These guidelines ensure the safety, quality, and reliability of the specialisedzed containers that manage substances at extremely low temperatures. Adherence to these standards is crucial to mitigate risks and prevent accidents.
Key codes and standards cover various aspects of cryogenic storage tank design, construction, and operation, including:
Table 2: Codes and Standards for Cryogenic Storage Tanks
| CODE/STANDARD | FOCUS |
|---|---|
| ASME B&PV Code Section VIII | Design principles for pressure vessels, including cryogenic tanks |
| API 620 | Design and construction of large welded low-pressure storage tanks |
| API 625 | Tank systems for refrigerated liquefied gas storage |
| NFPA 55 | Storage, use, and handling of gases in cryogenic systems |
| ISO 13458 | Cryogenic vessels – Safety devices for protection against excessive pressure |
| EN 13445 | Unfired pressure vessels, including cryogenic storage vessels |
| AISC 360 | Structural design of steel elements used in cryogenic tanks |
These codes provide comprehensive guidelines for design principles, materials, construction, safety devices, and structural considerations. Compliance with these standards ensures that cryogenic storage tanks are designed and constructed to withstand the unique challenges of extremely low temperatures and the associated hazards of cryogenic fluids.
Why Choose DSW Cryogenic Tanks
- Full compliance with ASME, API, and ISO standards
- Custom-engineered solutions for LNG and industrial gases
- Advanced vacuum insulation technology
- Global export experience
- Competitive pricing with factory-direct supply
DSW delivers high-performance cryogenic storage solutions tailored to your operational requirements.
TECHNICAL QUESTIONS
Frequently asked questions about Cryogenic Liquid Storage Tanks
A cryogenic storage tank is a vacuum-insulated, double-walled pressure vessel designed to store liquefied gases below −150°C. It uses a stainless steel inner vessel, carbon steel outer shell, and a vacuum-perlite or multilayer insulation system to minimise heat ingress and boil-off gas.
A VIT (Vacuum-Insulated Tank) is used for low-pressure liquid storage, while a VIE (Vacuum-Insulated Evaporator) integrates vaporisation to supply gas directly. VIE systems operate at higher pressures and are designed for continuous gas delivery.
Boil-off gas is reduced through high vacuum insulation, low thermal conductivity materials, and pressure control systems. In LNG systems, BOG can be recovered, recondensed, or reused to improve efficiency.
Inner vessels are typically made from austenitic stainless steel (304/316) for cryogenic toughness, while outer shells use carbon steel. Insulation includes perlite or multilayer systems under vacuum.
Key standards include ASME Section VIII for pressure vessels, API 620 and API 625 for LNG tanks, ISO 13458 for cryogenic vessels, and NFPA 55 for gas safety.
Pressure is managed using pressure-building systems, economisers, and relief valves. These components maintain stable operating pressure and ensure safety under varying load conditions.
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