Loading arm with gangway fall protection

The 43 Degrees of Liquid Sulfur

How to stay safe when loading and unloading liquid sulfur

By: Graeme Murphy, VP Strategy and Business Development

Sulfur is the 10th most abundant element in the universe. It accounts for almost 3 percent of our planet’s entire mass. Or to put it more contextually: If you combined all the sulfur that exists on Earth, you’d have enough to make two additional moons.

For how much sulfur there is, it helps that it’s also one of the most important and widely used materials. It’s essential to the chemical, industrial, manufacturing and crude oil industries, to name a few. It’s used to create products like rubbers, detergents, fungicides, plastics and fertilizers — and the world’s most widely used chemical: sulfuric acid.

Globally, about 70 million tons of sulfur are produced each year. The majority is produced by petroleum refineries and natural gas plants, which both generate sulfur as a byproduct of regular operations.

Sulfur’s large-scale production and increasing international need present loading facilities with unique and complex challenges.

The Liquid Sulfur Challenge

Sulfur is most easily transported as a liquid, which means that before it goes anywhere, it must first be heated to its melting point of 239 degrees Fahrenheit. During its transit, liquid sulfur must be kept within a 43-degree range — between 266 degrees and 309 degrees Fahrenheit — in order for safe loading and unloading to occur. This extremely hot range poses a serious threat if not handled properly.

The physical properties of liquid sulfur can also endanger workers. When sulfur burns, it forms sulfur dioxide, a toxic gas that is fatal if inhaled. That’s why it’s critical to keep it under that 309-degree mark. Additionally, high concentrations of sulfuric vapor and water vapor can lead to deadly explosions, and liquid sulfur itself is highly flammable. Your facility’s equipment and crew need always to properly address these dangers.

The Right Loading Arm for the Job

When handling a volatile material like sulfur, it’s important that safe, smart solutions are built into your loading system and applications from the start. These features are key to protecting both your employees and the environment.

Parallel loading arms are ideal for working with liquid sulfur. A parallel arm is composed of two boom loaders connected together so that all movements are performed in unison. One boom is used to load the liquid sulfur while the other is used for vapor recovery, keeping dangerous vapors from leaking out into the air. Even with two booms, this loading arm can be operated as easily as a single arm.

Safe operation of the arm is critical when handling liquid sulfur. Electro-hydraulically controlled systems are preferred for their precise, smooth movements. These systems also control flow rates via a hydraulically actuated flow-control valve, which helps ensure the safest transfer through the loading arm. The arm itself can be operated using a remote pendant control unit, which allows the worker to operate the arm from a safe distance.

Automatic Safeguards Built In

Built-in electric heat tracing allows the loading arm to maintain a safe, constant temperature. The trace heating is insulated and clad in stainless steel. With sensors located near the swivel joints and elbows, you can be sure that the temperature is being accurately monitored and adjusted accordingly.

Because of liquid sulfur’s flammable nature, it’s imperative to eliminate any possible ignition sources. Electrical static bonding straps placed across all swivel joints eliminate any difference in electrical potential between the arm’s parts. These straps ensure that no sparks or static electricity will be produced when the liquid crosses the swivel joints.

Your loading arm can also keep workers safe from dangerous sulfuric vapor. During loading, a truck will sink on its axles due to the weight. If you’re not careful, vapor can escape through the gap that appears between the hatch and the vapor recovery cone — immediately endangering nearby workers. A built-in powered hold-down device ensures that permanent, steady pressure is applied to the vapor recovery cone.

Make Safety Simpler

Safe operation of your loading system is easy when you use smart equipment. A Programmable Logic Controller (PLC) system can efficiently handle complex tasks like data processing and equipment automation. The PLC quickly monitors information from a number of sources such as the hold-down device and the arm’s pressure sensors so a worker can see comprehensive data at any given time.

The SmartTech LOGIC Overfill and Grounding controller communicates with the PLC to keep your workers and the environment safe. The controller is an all-in-one system for terminals. It not only prevents overfill, but also monitors the loading arm position and logs external conditions like humidity and temperature. If any built-in safety systems are breached, this integrated system will shut down the loading operation, preventing any potential accident or injury.

Loading and unloading liquid sulfur comes with many risks. The best way to stay safe and productive is to use equipment with built-in safety features that minimize the risk of human error. SafeRack’s loading arms are manufactured with safety in mind. Plus, we only use the most durable materials to ensure that your loading solution is not only safe, but will last in tough situations like when loading liquid sulfur.

For more information on loading and handling specific product sets, get in touch with your local SafeRack representative.