Helping Chlorine Carriers Stay Compliant

By OPW | Mar 27, 2020

The current design of the United States transportation system dictates that railroads must play a key role in the shipping of hazardous materials (hazmat), of which chlorine is the among the most prominent. Fortunately, the railroads themselves, along with the companies that build railcars and develop the components that outfit them, have taken great pride in creating the safest, most reliable solutions. In fact, according to the Association of American Railroads (AAR), in 2018, more than 99.999% of the hazardous materials moved by rail in the U.S. reached their destination without an accident-caused product release.

In order to achieve this enviable safety record, the railcars and their suppliers work hand-in-hand with a number of governmental oversight and regulating agencies to produce a set of standards that will help optimize rail-based hazmat shipping. Specifically, the rail transport of hazmat in the U.S. is overseen by three entities – the Federal Railroad Administration (FRA), Pipeline and Hazardous Materials Safety Administration (PHSMA) and Department of Homeland Security (DHS).

The railroads work with these regulating bodies, along with other state and local entities, on hazmat-related issues. Among the more pressing issues are railcar design, railroad security and emergency response. An agreed-upon set of regulations dictates the ways that the railroads and their equipment suppliers must stay in compliance with the established standards. For many, the difficulty in staying compliant is that most regulations are actually moving targets, prone to periodic revisions and modifications that must be tracked, while the next new regulation is just around the corner.

This means that there are a number of ways that chlorine carriers can find themselves out of compliance, often through no fault of their own. To aid in the never-ending battle to stay compliant, many railcar component developers and suppliers like Midland have made a commitment to designing Advanced Chlorine Railcar Assembly equipment that addresses all of the FRA, PHMSA and DHS compliance needs of chlorine carriers. Among the highlights of this equipment package are:

  • All primary seals are located below the surface of the pressure plate, which means that the chlorine lading will be contained even if all of the valves are sheared off the railcar during an accident.
  • All valves are constructed of superior corrosion-resistant materials, such as Monel®, Inconel® x750, Hastelloy® C and Stellite 21.
  • The number of angle valves is reduced from four to three (two liquid and one vapor), which eliminates a tank opening and, by extension, a potential leak path.
  • A new check valve design creates positive action between the check valve and angle valve, while eliminating accidental checking during offloading and allowing verification of the check valve’s seal integrity.
  • Can be used with protective housings that have larger diameters, resulting in increased security and more room for personnel to operate the valves.
  • Compatibility with current Emergency Shut Down (ESD) actuators that utilize existing loading-rack configurations.
  • Pressure relief and angle valves that can be removed for testing and maintenance without needing to clean the car, along with access to all internal components with no need to remove the pressure plate.

Additionally, Midland has developed an Enhanced Fittings Package for use on Next Generation Rail Tank Cars (NGRTC) that are rapidly becoming the first choice for chlorine shipping in the U.S. The specific equipment in this chlorine-dedicated Enhanced Fittings Package includes pressure relief valves, angle valves, check valves and pressure plates. All components in the Enhanced Fittings Package meet the regulatory requirements from the FRA and AAR.

For more information on Midland, and its complete portfolio of railcar products for the compliance-satisfying transport of chlorine, please visit