Fuel loading and unloading can create serious safety, environmental, and operational challenges. From flammable vapours to product spills, even a routine transfer can become risky, especially if you don’t have the right equipment.
That’s why more and more site managers are investing in proper safety systems, such as loading arms with integrated vapour recovery. These systems help capture displaced vapours during loading or unloading, reducing emissions and helping protect operators, equipment, and the environment.
Below, we will explain how vapour recovery loading arms work, why they are useful for fuel tanker loading and unloading, and how Northern Platforms can help you find the right solution for your site.
What Are Vapour Recovery Systems?
A vapour recovery system is a closed-loop configuration designed to capture hydrocarbon vapours that are displaced or released during the transfer of volatile liquids.
These systems are used across a wide range of industries, from petroleum terminals and chemical plants to food and beverage facilities and gas stations. In every application, the goal is the same: keep Volatile Organic Compounds (VOCs) out of the air.
How Do Vapour Recovery Systems Work?
In the context of tanker truck loading and unloading, the basic principles of vapour recovery systems are simple. The process unfolds in three stages:
1. Vapour Capture When the loading arm connects to the tanker truck, a vapour recovery coupler or hose creates an airtight seal at the connection point. As product flows in, displaced vapours are drawn into the vapour return circuit rather than escaping through the fill opening.
2. Vapour Transfer The captured vapours travel back through the loading arm’s vapour return line, either via a piggyback hose welded to the product arm, or through a dedicated second arm in a dual-arm configuration.
3. Vapour Recovery and Re-use At the receiving end, captured vapours are processed — either returned directly to the product storage tank, compressed and condensed back into liquid form, or fed into a vapour combustion or treatment unit.
The end result is a closed system: product flows in, vapours flow back, and nothing escapes to atmosphere during normal operation.
Benefits of Vapour Recovery Systems
More and more operations managers are adding vapour recovery systems to their tanker truck loading systems. Here’s why:
Environmental Impact
Hydrocarbon vapours released during fuel loading are composed primarily of volatile organic compounds (VOCs). Canada’s Canadian Environmental Protection Act (CEPA) establishes regulations on VOC emissions from fuel loading and storage operations, and provincial regulators in Alberta and BC have their own emissions requirements for petroleum handling facilities. Vapour recovery systems capable of capturing upwards of 95% of displaced vapours are required by these regulations.
Worker Safety
Displaced vapours can also be dangerous for workers. Without vapour recovery, operators can be exposed to a cloud of flammable vapour throughout the loading process, which creates a serious hazard.
A sealed vapour recovery system eliminates that exposure at the source. Workers on the loading platform aren’t breathing displaced product vapours and fire hazards are substantially lowered. For sites already managing fall protection, PPE requirements, and emergency shutoff systems, vapour recovery is an important piece of the overall site safety picture.
Operational Efficiency
The right vapour recovery system can also reduce time on the loading rack. At Northern Platforms, we use OPW’s Drylok™ Vapour Recovery Technology, which helps reduces the average time to connect a loading arm to railcar valves to 35–40 seconds. Operators simply turn a lever to connect; no pipe wrenches, cheater bars, or hammers required. That reduction in connection time adds up fast across a high-volume loading operation.
Vapour Recovery in Tanker Truck Loading and Unloading
At Northern Platforms, we use OPW Engineered Systems products to offer two primary vapour recovery loading arm configurations:
Piggyback Style Arm A simpler and more compact design where the vapour return line is welded directly to the product loading arm. The vapour hose runs parallel to the arm structure and connects at the dome hatch alongside the product drop tube. This configuration works well for lower-volume applications or sites where space at the loading rack is limited.
Dual Arm / Siamese Configuration The more commonly specified design for higher-volume or more demanding applications. This configuration uses two separate loading arms, one for product transfer and one for vapour recovery, joined together at the inner boom structure so they operate as a single, counterbalanced unit. The dual arm arrangement provides better flow capacity for the vapour return circuit and is the preferred setup for most fuel terminal and petroleum loading applications.
In addition to core system design, Northern Platforms offers a range of customization options to match the specific demands of your product and operating environment, including steam jacketing, heat tracing, insulation packages, and specialized couplings. Contact us with your site requirements, and we can recommend the right configuration for your operation.
Request a Quote Today
Interested in a new fuel tanker unloading system or looking to improve your existing operation? The Northern Platforms team is here to help. Contact us today with details about your project for a free quote. For businesses based in Alberta, we also offer free site visits and assessments.