Direct Answer

Pressurized containers are used in hazardous areas because they provide a controlled internal environment that protects electrical and mechanical equipment from potentially explosive gases, vapors, or dust.

Unlike standard equipment containers, pressurized containers are designed to maintain positive internal pressure, preventing hazardous substances from entering the enclosure and allowing sensitive equipment to operate safely in classified areas.

1. Positive Pressure Prevents Hazardous Gas Ingress

The core function of a pressurized container is maintaining clean internal conditions by continuously supplying clean air or gas at a higher pressure than the surrounding hazardous environment.

In hazardous areas, explosive gases or vapors may exist due to industrial processes.

A positive pressure system helps prevent these substances from entering the container by maintaining:

• Controlled internal pressure
• Continuous air supply
• Monitored pressure levels
• Safe ventilation conditions

This allows electrical equipment that may not otherwise be suitable for hazardous locations to operate within a protected environment.

2. Pressurized Containers Enable Equipment Installation in Hazardous Areas

A major advantage of pressurized containers is that they allow critical equipment to be installed closer to hazardous operations.

Applications may include:

• Control rooms
• Electrical rooms
• Analyzer shelters
• Instrumentation rooms
• Remote operation units

Instead of locating equipment far away from the process area, a pressurized container provides a protected workspace near the operating site.

This can improve operational efficiency and simplify project layout.

3. HVAC and Ventilation Design Are Critical Components

The performance of a pressurized container depends heavily on proper ventilation and environmental control design.

The system must consider:

• Air supply and exhaust
• Pressure monitoring
• Temperature control
• Humidity management
• Equipment heat generation

HVAC design is not only for personnel comfort. It directly affects equipment reliability and the stability of the pressurized environment.

4. Hazardous Area Requirements Influence Container Design

Pressurized containers must be designed according to the hazardous area classification and applicable project requirements.

Important considerations include:

• Zone classification
• Electrical equipment selection
• Purging and pressurization requirements
• Monitoring systems
• Emergency shutdown functions

Depending on the application, projects may require compliance with standards such as:

• IECEx
• ATEX
• IEC 60079 series

The design approach depends on the specific operating environment and equipment installed inside the container.

5. Custom Engineering Is Essential for Pressurized Containers

Pressurized containers require customized engineering because each project has different equipment, environmental, and safety requirements.

Key design inputs include:

• Installed equipment list
• Hazardous area classification
• Power requirements
• Internal layout
• Operating temperature range
• Certification requirements

A successful design must balance safety, functionality, maintenance access, and long-term reliability.

What Should Be Considered Before Selecting a Pressurized Container?

The correct pressurized container should be selected based on the complete application requirements rather than container size alone.

Important factors include:

• Is the installation area Zone 1 or Zone 2?
• What equipment will be installed inside?
• What protection standard is required?
• What environmental conditions will the container face?
• Are future maintenance requirements considered?

These factors determine the appropriate pressurization system and container design.

FAQ

1. What is the difference between a normal container and a pressurized container?

A normal container mainly provides physical protection, while a pressurized container creates a controlled internal environment to prevent hazardous gases or vapors from entering and affecting installed equipment.

2. Can pressurized containers be used in Zone 1 and Zone 2 hazardous areas?

Yes, pressurized containers can be designed for hazardous area applications, but the required protection level depends on the project classification, equipment requirements, and applicable standards.

3. Why is HVAC important in a pressurized container?

HVAC maintains temperature, air quality, and pressure stability, which are essential for protecting equipment and maintaining reliable operation in hazardous environments.

Conclusion

A pressurized container is not simply an enclosed equipment room. It is an engineered protection system that combines positive pressure control, ventilation, environmental management, and hazardous area requirements.

For industries such as oil and gas, petrochemical, and offshore energy, pressurized containers provide a practical solution for installing critical equipment in areas where explosive atmospheres may exist.

The most reliable pressurized container designs are developed around the actual hazardous classification, installed equipment, and operating conditions.

TLS Offshore Containers / TLS Energy is a global supplier of standard and customised containerised solutions. 

Wherever you are in the world, TLS can help you. Please contact us.

Summary

TLS A60 accommodation modules are portable, fire-rated, and weatherproof living containers designed to protect personnel and maintain operational continuity on offshore oil and gas platforms, wind farm substations, and marine vessels. Certified to withstand 60 minutes of direct structural fire exposure under international maritime standards (such as ABS and DNV), these modular units combine passive fire protection, acoustic insulation, HVAC climate control, and ergonomic interior layouts to support offshore workforces during extended deployments.

What Is an A60 Fire Rating in Offshore Accommodations?

The A60 standard defines a passive fire protection rating established by the International Maritime Organization (IMO) FTP Code and certified by classification societies like the American Bureau of Shipping (ABS) and DNV.

• Fire Barrier Protection: An A60-rated bulkhead or deck prevents the passage of flame and smoke for 60 minutes.
• Thermal Insulation Limits: The unexposed side of the structure must not rise in temperature by more than 139°C (250°F) above ambient within the 60-minute window, preventing auto-ignition of interior materials during a major thermal event.

TLS builds its accommodation modules to comply strictly with these requirements, providing critical shelter during emergency evacuations or hydrocarbon fire scenarios.

Key Technical Specifications & Features

1. Fire, Gas, and Blast Protection

• Structural Rating: Built with heavy-duty marine-grade steel framing and A60 structural fire insulation.
• Overpressure & Gas Detection: Integrated positive-pressure HVAC systems prevent external hazardous gases or hydrocarbon vapors from entering living quarters.
• Integrated Safety Systems: Equipped with pre-wired fire and gas (F&G) detection systems, emergency shutdown (ESD) interfaces, and fire dampers.

2. Modular Scalability and Layout Flexibility

• Capacity Options: Available in single, double, quad, or 8-person sleeper configurations to accommodate varied crew sizes.
• Interconnection: Designed for stackable (up to multi-tier complexes) and linkable installation using standardized ISO corner castings and twist-locks.
• Multi-Purpose Configurations: Modules can be fitted as bedrooms, offices, recreation rooms, mess halls, or sanitary facilities (en-suite wet units).

3. Environmental Controls and Crew Comfort

• HVAC & Climate Control: Heavy-duty dual HVAC systems engineered for extreme ambient temperatures ranging from arctic cold to tropical heat.
• Acoustic Insulation: Noise-attenuating interior panelling reduces ambient marine and machinery noise to under 45–50 dB(A), improving sleep quality and reducing crew fatigue.
• Ergonomics & Durability: Furnished with high-density flame-retardant mattresses, integrated storage, marine-grade sanitary fixtures, and customizable workspaces.

4. Regulatory Compliance and Certification

TLS A60 modules comply with critical global offshore standards:

• IMO SOLAS (Safety of Life at Sea)
• ABS / DNV Classification Rules for offshore portable modules

Primary Applications Across Offshore Sectors

• Oil & Gas Platforms: Temporary living quarters (TLQ) during hook-up, commissioning, shutdown, or maintenance campaigns.
• Offshore Wind Farms: Living and office space for technicians on offshore converter stations, substations, and cable-laying vessels.
• Support & Service Vessels: Expansion quarters for accommodation work barges, ROV support ships, and pipelay vessels.

Frequently Asked Questions

Why choose A60 modular accommodations over permanent structures?

A60 modular units offer rapid mobilization, flexible capacity adjustment, and lower capital expenditure compared to permanent structural modifications. They can be certified ashore, lifted via standard marine cranes, and integrated into existing vessel power and utility systems with minimal downtime.

How do A60 modules maintain air quality in hazardous environments?

TLS modules utilize positive-pressure HVAC units equipped with automatic gas detection shut-off dampers. If external airborne gas or smoke is detected, the HVAC automatically isolates fresh air intake and activates recirculating air filtration to maintain a safe atmosphere inside.

TLS Offshore Containers / TLS Energy is a global supplier of standard and customised containerised solutions. 

Wherever you are in the world, TLS can help you. Please contact us.

More information about accommodation modules, offshore accommodation cabins, gallery module, mess module, etc. Please download the TLS accommodation modular brochure, TLS 20ft offshore accommodation container, and TLS ABS-approved offshore accommodation module brochure for reference.

An offshore workshop container is a heavy-duty, purpose-built modular enclosure engineered for maintenance and repair operations on offshore oil rigs, wind farm installations, and marine vessels. Unlike standard shipping containers or land-based workshops, an offshore unit is specifically certified and equipped to endure dynamic crane lifting, aggressive salt-spray corrosion, hazardous atmosphere exposures, and intense structural stress.

1. Core Engineering and Structural Requirements

To operate safely in harsh marine environments, an offshore workshop container relies on four primary engineering pillars:

Dynamic Lifting and Structural Integrity

• DNV 2.7-1 / EN 12079 Certification: Offshore containers must withstand dynamic impact loads caused by ocean swells during vessel-to-rig crane transfers. Frames feature reinforced corner posts, integrated padeyes, and certified four-leg wire rope slings.
• Heavy Floor Loading Capacity: Internal floors are reinforced with heavy-duty steel chequered plates or anti-slip composite decking rated for heavy machinery (such as lathes, hydraulic presses, and pump spares).

C5-M Marine Anti-Corrosion Systems

• Surface Preparation: Structural steel undergoes ISO 8501-1 Sa 2.5 abrasive blast cleaning prior to coating application.
• Multi-Layer Paint Specification: Utilizes ISO 12944 C5-M paint systems—typically consisting of a zinc-rich epoxy primer, an intermediate epoxy tie-coat, and a UV-resistant polyurethane topcoat (total dry film thickness ≥ 280μm). External hardware, door hinges, and fasteners are fabricated from 316L stainless steel.

Internal Ergonomics and Equipment Restraints

• Vibration and Load Restraints: Workbenches, tool racks, and heavy machinery are welded directly to the structural framework or secured with heavy-duty tie-down points to prevent equipment movement during high-sea transit.
• Spatial Efficiency: Incorporates wall-mounted tool boards, lockable drawer units, overhead gantry cranes, and cable routing channels to maximize floor space for technicians.

Electrical and Utility System Integration

• Ex-Proof Equipment Options: When deployed in Zone 1 or Zone 2 hazardous areas, electrical systems utilize ATEX/IECEx-certified explosion-proof junction boxes, lighting, and HVAC units.
• Power Distribution: Includes multi-voltage transformers (e.g., converting 440V/480V down to 220V/110V), pneumatic air lines, emergency stop circuits, and external shore-power connections.

2. Standard Container vs. Offshore Workshop Container

Structural Standard

• Standard Land Workshop: ISO 1496 (designed for static stacking and land logistics).
• Offshore Workshop: DNV 2.7-1 / EN 12079 (certified for dynamic marine crane lifting at sea).

Corrosion Protection

• Standard Land Workshop: Standard alkyd or acrylic industrial paint coatings.
• Offshore Workshop: C5-M Multi-layer Marine Epoxy/Polyurethane System over Sa 2.5 blast cleaning.

Lifting Mechanism

• Standard Land Workshop: Corner castings for forklifts or top spreaders.
• Offshore Workshop: Certified Padeyes with DNV-certified Four-Leg Wire Rope Sling Assemblies.

Hazardous Area Options

• Standard Land Workshop: Unrated (suitable for Safe Areas only).
• Offshore Workshop: ATEX / IECEx Zone 1 & Zone 2 Options available.

Fire Protection

• Standard Land Workshop: Non-rated or basic thermal insulation.
• Offshore Workshop: SOLAS A60 Fire-Rated Walls & Doors (optional).

3. Key Industrial Applications

• Offshore Oil and Gas Rigs: Serves as a dedicated mechanical, electrical, or hydraulic repair hub on drilling rigs, FPSO, and fixed platforms.
• Offshore Wind Farm Maintenance: Accommodates wind turbine technicians, specialty tooling, and electrical diagnostics during offshore installation and maintenance.
• Marine Subsea and ROV Operations: Houses subsea tool maintenance gear, hydraulic power units, and Remote Operated Vehicle (ROV) spare parts.

4. Frequently Asked Questions (FAQ)

What is the primary difference between ISO containers and DNV 2.7-1 offshore containers?

Answer: ISO containers are designed solely for static stacking and standardized freight transport. DNV 2.7-1 containers are certified for dynamic offshore crane lifting at sea, featuring higher structural yield strength, specialized padeyes, and rigorous non-destructive testing (NDT) during manufacture.

How is corrosion managed on offshore workshop containers?

Answer: Corrosion is mitigated through hot-dip galvanization or multi-layer C5-M marine coating systems applied over Sa 2.5 sandblasted steel. Stainless steel 316L hardware is used for external fasteners, door hinges, and junction boxes.

What information is required to design an offshore workshop container?

Answer: Essential design inputs include: total footprint dimensions (e.g., 10ft, 20ft), total payload/equipment weight, operating ambient temperatures, electrical voltage requirements, hazardous area classification (Safe Area vs. Zone 1/2), and certification requirements (DNV 2.7-1, ABS, Lloyd's Register).

TLS Offshore Containers / TLS Energy is a global supplier of standard and customised containerised solutions. 

Wherever you are in the world, TLS can help you. Please contact us.

Product brochures:

Offshore total pressurised container solutions

Offshore pressurised mud logging cabin brochure

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