Marine Vapor Recovery & Barge Degassing Services

Q: Does Envent meet USCG standards for marine vapor recovery?

Yes. Envent's systems are fully compliant with Title 33 CFR Part 154, governing marine vapor control systems, as well as 46 CFR 39 for tank vessels.

Q: What is the role of the Envent Dock Safety Unit (EDSU)?

The EDSU is a skid-mounted safety system that incorporates engineered controls, including safety interlocks and detonation arrestors, to maintain vapor concentrations outside the explosive range.

Q: Can Envent help avoid the capital costs of a fixed MVR facility?

Yes. Envent's portable systems provide the performance of a fixed facility without the capital cost, CEQA permitting, or permanent construction delays.

North America’s Leader in Portable Marine Vapor Recovery Systems

Envent Corporation’s Portable Marine Vapor Recovery Systems are U.S. Coast Guard (USCG) compliant, meeting all requirements outlined under 33 CFR 154 Subpart P (Vapor Control Systems) and 46 CFR 39 (Vapor Control Systems for Tank Vessels). These federal standards govern the design, operation, and certification of vapor control systems used during high-stakes marine loading operations.

Our complete systems, the Envent Mobile Emission Control System (EMECS) and the Envent Dock Safety Unit (EDSU) are engineered to safely and efficiently destroy explosive vapors from marine cargo vessels during hydrocarbon loading activities, making sure full compliance with USCG-approved safety and emission control protocols.

The Critical Need for Marine Emission Control

The Clean Air Act of 1990 mandates the control of volatile organic compound (VOC) emissions from all sources, including marine loading operations. To meet these requirements, Marine Vapor Recovery (MVR) systems at terminals must comply with both U.S. Coast Guard (USCG) and U.S. Environmental Protection Agency (EPA) regulations.

When new opportunities arise at your marine terminal, Envent delivers immediate, compliant solutions. Our portable systems provide all the performance of a fixed facility, without the capital cost, enabling terminals to load safely, maintain full environmental compliance, and protect nearby communities and waterways.

Specialized Marine Vapor Control

Barge & Marine Vessel Degassing

Degassing of barges and ships follows the same principles as land-based tank degassing, as both contain volatile organic compounds (VOCs) that must be controlled and destroyed under local, state, and federal Clean Air Act regulations.

Envent Corporation’s Marine Vapor Control Systems are fully U.S. Coast Guard (USCG) compliant, meeting all requirements under 33 CFR 154 Subpart P for vapor control and destruction during marine operations. Envent delivers trusted, USCG-approved solutions for marine vapor control and degassing proven in ports and terminals across North America.

Regulatory Requirements & Compliance

The Clean Air Act of 1990 requires control of VOC emissions from all sources, including marine loading, so Marine Vapor Recovery systems at terminals must comply with both U.S. Coast Guard and U.S. Environmental Protection Agency regulations to keep your project in full regulatory compliance.

Title 33 CFR Part 154: USCG rules for marine vapor control systems.
Title 40 CFR Parts 61 and 63: EPA Clean Air Act rules for hazardous air pollutants and VOC emissions control.

Envent, setting the standard for compliant, USCG- and EPA-approved marine vapor control.

Featured case study

Mid-West, USCG Certified Marine Vapor Recovery System

The Problem : A refinery needed to perform pipeline maintenance without halting barge shipments. A total shutdown would have cost over $3M in lost revenue and violated strict USCG 33 CFR 154 emission standards.

What We Did : Envent provided a complete temporary Marine Vapor Control System (MVCS). We handled the vapor flow using an EMECS thermal oxidizer and a Dock Safety Unit (DSU), allowing loading to continue safely while the pipeline was out of service.

The Result : The refinery avoided a $3M loss and maintained 100% regulatory compliance. We guaranteed >99.9% destruction efficiency and shortened the operational impact with zero safety incidents.

Leader in Mobile Marine Vapor Control

Envent Corporation is the North American leader in mobile marine vapor control for ships and barges. With systems ready to deploy to ports across the continent, Envent is the industry’s #1 choice for safe, compliant, and cost-effective marine vapor management.

Our OQ-qualified engineers work directly with your team to make sure all operations meet U.S. Coast Guard (USCG) standards under 33 CFR 154, without the need for a time-consuming “gap analysis.”

EPA BACT Standards:
Our vapor combustors are source-tested to meet U.S. EPA Best Available Control Technology (BACT) standards and are proven to deliver complete destruction efficiency with full safety redundancy.
Engineered Safety:
The Envent Mobile Emission Control System (EMECS) and Envent Dock Safety Unit (EDSU) eliminate the need for permanent design, engineering, or permitting investments, allowing you to operate safely and in compliance without capital expense.

Core Benefits of the EMECS / EDSU Systems

By using our portable marine vapor recovery technology, terminals gain significant operational advantages:

Eliminate Capital Expenditure
No massive upfront investment for permanent infrastructure.
Eliminate Engineering
Envent Engineers handle everything, from setup to operation.
Eliminate CEQA Permitting
Streamlined deployment avoids complex state environmental quality reviews.
USCG Compliance (33 CFR 154)
Systems are pre-certified; no “gap analysis” required.
Fully Integrated Dock Safety Unit
Skid-mounted and operator-controlled for maximum reliability.
Pre-Approved HAZOP System
Safety protocols are already established and verified.
Avoid Building Permits
Mobile equipment bypasses traditional construction permitting delays.
Avoid Air Permitting
Envent manages the process to make sure your project stays compliant.

Envent delivers flexibility, compliance, and confidence, wherever your marine loading operations take you.

Featured case study

Liquefied Natural Gas (LNG) Cargo Ship Degassing

The Problem : The first U.S. LNG-fueled container ship required urgent valve repairs on twin 1,200 m³ cryogenic fuel tanks. The project faced extreme −260 °F temperatures, strict USCG 33 CFR 127 regulations, and a rigid commercial sailing schedule with no room for delay.

What We Did : Envent engineered a complete mobile solution using an EMECS-42 thermal oxidizer. To handle the extreme cold, we used a specialized hot nitrogen splice-in to safely heat vapors, preventing brittle fracture of the equipment while maintaining >99.9% destruction efficiency.

The Result : The tanks were successfully degassed and inerted with zero incidents or LEL excursions. We guaranteed 100% regulatory compliance, allowing the ship to sail on schedule and setting the U.S. benchmark for mobile cryogenic marine degassing.

Envent Dock Safety Unit (EDSU)

The Envent Dock Safety Unit (EDSU) is a skid-mounted safety system positioned near the facility’s vapor connection, typically on the wharf or dock adjacent to the marine vessel being loaded with hydrocarbon commodities.

The EDSU receives vapors from marine cargo holds and incorporates multiple layers of engineered safety controls, including safety interlocks, detonation arrestors, and a vapor-enriching system designed to maintain vapor concentrations outside the explosive range before directing them to the vapor destruction unit. This system is fully U.S. Coast Guard (USCG) compliant and designed for rapid mobilization and quick setup.

Envent Mobile Emission Control System (EMECS)

The The Envent Mobile Emission Control System (EMECS) is a horizontal combustion thermal oxidizer engineered for Marine Vapor Recovery applications. Capable of operating at temperatures exceeding 1,400°F, the EMECS makes sure complete combustion and destruction of hydrocarbon vapors generated during marine loading operations.

High-Capacity Performance
Available in sizes ranging from 20 to 77 MMBTU/hr.
Safety First
Features fire-safe valves, redundant detonation arrestors, and real-time monitoring to instantly detect and respond to process upsets.
Strategic Placement
Typically positioned away from the wharf in a non-classified safe zone (minimum of 30 meters from the nearest active berth).

When paired with the Envent Dock Safety Unit (EDSU), the EMECS forms a fully certified, 100% compliant Marine Vapor Control System, designed for both short-term and long-term ship or barge loading vapor control needs.

Featured case study

Liquefied Natural Gas (LNG) Barge Degassing – Alabama

The Problem: A freight vessel powered by Liquefied Natural Gas (LNG) needed to degas its fuel tanks for maintenance. Clearing high concentrations of methane in a sensitive port environment required a solution that prevented safety risks and met strict maritime emissions standards.

What We Did: Envent deployed a specialized mobile thermal oxidizer capable of handling high-purity methane streams. We engineered a secure vapor-recovery connection from the ship’s tanks to our combustion unit, while OQ-qualified technicians provided 24/7 monitoring to maintain stable and complete vapor destruction..

The Result: The tanks were successfully cleared with 99.9% destruction efficiency, meeting all port safety and environmental regulations. Our rapid response prevented project delays, allowing the vessel to begin maintenance on schedule with zero emissions excursions.

Explore Envent’s Recent Marine Vapor Recovery & Barge Degassing Projects

From critical-path port operations to emergency maritime responses, Envent delivers engineering-driven results across the United States and Canada. Our project history showcases our ability to maintain 100% compliance while improving operational timelines for the world’s leading marine terminals and shipping operators.

Liquefied Natural Gas (LNG) Cargo Ship Degassing

June 17, 2025

Mid-West, USCG Certified Marine Vapor Recovery System

June 17, 2025

California Refinery Barge Loading

July 2023

Liquefied Natural Gas (LNG) Barge Degassing – Alabama

June 17, 2025

Marine Vapor Recovery & Barge Degassing FAQs

Does Envent meet USCG standards?

Yes. Our systems are fully compliant with Title 33, CFR, Part 154, governing marine vapor control systems.

Are your systems EPA approved?

Yes. We comply with Title 40, CFR, Parts 61 and 63 under the Clean Air Act, governing the control of hazardous air pollutants and VOC emissions.

Does Envent meet USCG standards for marine vapor recovery?

Yes. Our systems are fully compliant with Title 33, CFR, Part 154, which governs marine vapor control systems. We handle the engineering and safety requirements so your terminal can operate without a time-consuming “gap analysis”.

Are your mobile marine systems EPA approved?

Yes. We comply with Title 40, CFR, Parts 61 and 63 under the Clean Air Act. Our thermal oxidizers are source-tested to meet EPA BACT (Best Available Control Technology) standards, delivering complete destruction efficiency.

What types of vessels and operations do you support?

Envent supports a wide range of tank vessels under 46 CFR 39 standards. We provide complete solutions for barge and ship loading, as well as marine vessel degassing to remove VOCs before maintenance or inspections.

What is the role of the Envent Dock Safety Unit (EDSU)?

The EDSU is a skid-mounted system positioned on the wharf that acts as the primary safety interface. It provides multiple layers of protection, including detonation arrestors and a vapor-enriching system to keep vapor concentrations outside the explosive range.

How does the EMECS system ensure safe vapor destruction?

The EMECS is a high-capacity thermal oxidizer that operates at temperatures exceeding 1,400°F to guarantee complete combustion. It is strategically placed in a non-classified safe zone, typically at least 30 meters from the active berth.

Can Envent help us avoid the capital costs of a fixed MVR facility?

Absolutely. Our portable systems provide the performance of a fixed facility without the massive capital expenditure. This allows terminals to handle new hydrocarbon loading opportunities immediately.

Does Envent manage the environmental permitting process?

Yes. We manage the air permitting process and make sure that your project avoids complex CEQA permitting and traditional building permit delays.

What types of tank conditions can you degas?

Envent has successfully degassed thousands of tanks under various conditions, including sunken roofs, new construction, demolition, and routine product transfers. We provide complete management of the process to ensure a zero-leak, zero-visible-flame profile.

Immediate, USCG-Compliant Marine Vapor Solutions

Expand your terminal’s capacity without the capital expense of fixed infrastructure. Envent’s engineering team provides complete USCG-compliant vapor recovery and degassing solutions that shorten your project timelines. We guarantee 100% regulatory standing and handle all permitting to keep your marine operations moving safely.