.png)
In 2023, America's railroads transported 181.2 million tons of chemicals. Many of these are hazardous in some way—toxic, explosive, or otherwise dangerous. Tank cars are also used to transport food-grade liquids, such as milk.
The vast majority of these shipments get to their destination safely, but this is not an accident. The hazmat accident rate is at its lowest ever, down 75% since 2000. However, when accidents do happen, they can be severe, due to the quantity of materials involved. Shippers are responsible for tank car safety, and low-pressure relief valves are a key part of that.
Choosing the right valve helps make sure that you are not responsible for an accident that contaminates an entire neighborhood. McKenzie is a resource for high-quality tank car components that balance capacity, safety, and efficiency.
Understanding what to look for helps you keep people safe and also reduces operational downtime and costs.
Meeting Operational Needs Without Compromise
The key here is to meet all operational needs. You can't compromise on efficiency to preserve safety, or you will experience shipping delays that can cause problems for you and your customers. You can't compromise on capacity, or you will need to run longer trains, using more fuel and increasing costs.
Here are some things to consider:
Understanding Tank Car Capacities
You want your tank cars to run as close to capacity as you can safely manage for most applications. Rarely, you may have to move a smaller volume, but in most cases, you are trying to run your cars full.
Material density impacts maximum load limits. Lighter materials put less strain on the base of the car, while heavier ones may require a smaller tank-to-car ratio. Most tank cars are designed to carry a specific material or class of materials.
Temperature and pressure affect density. For some materials, even the weather can impact load limits, with higher temperatures meaning that you have to load more lightly. Tank cars keep materials under pressure, and a temperature change can be dangerous. This is where relief valves come in, preventing a potential explosion or implosion of a car.
Factors Influencing Capacity
Material type influences capacity more than anything else. Liquids, gases, and hazardous materials have different capacity limits. Reducing the capacity for hazardous materials lowers the danger created by a leak and helps protect people and the environment. At the same time, fewer, larger cars are more efficient.
In some industries, load limits are set by regulations to prevent shippers from overloading cars. In 1970, the Federal Railroad Administration limited the size of tank cars to a gross rail load (GRL) of 263,000 pounds and a capacity of 34,500 gallons. These limits remain in place, with evolving standards to ensure minimum requirements for components such as brakes and wheels. There is, however, growing demand for larger cars and the Association of American Railroads (AAR) has developed standards for higher weights.
Overloading a tank car is dangerous. It can also increase wear and reduce the efficiency of brakes, greatly increasing the risk of an accident. Generally, because of the risk of pressure changes and temperature-based expansion, cars are loaded to the stenciled limit and are never completely full.
Customizing for Specific Applications
Common materials, such as natural gas, allow you to use standardized tank cars and standardized components. If, however, you are transporting more specialized chemicals, you may need your tank cars tailored to your unique operational requirements.
This is an area in which McKenzie Valve can provide significant support. We can use advanced tech, such as 3D printing, to quickly customize tank car valves. This process is called rapid prototyping, and we can test multiple configurations and materials quickly to find the ideal solution for your needs.
Mitigating Risks During Transport
Tank car safety valves are part, but not the whole, of mitigating transport risks. If you are transporting hazardous materials, then you need to mitigate risks as much as possible. Some things to consider:
Critical Safety Features in Tank Cars
Overpressure events are the worst fear of anyone moving hazardous materials. Overpressure events can happen from overloading, temperature gradients, or exposure to external heat sources. A chain reaction can occur when one car catches fire and the heat created by it causes overpressure to happen in the ones next to it, which can then spread. When this happens, a rail car can cause catastrophic failure, destroying the tank and spilling its entire contents. Pressure relief devices are designed to limit the buildup under fire conditions. In fact, some tank cars are required to survive a 100-minute, fully engulfing fire without catastrophic failure.
Most of this is met by safety valves, but tank cars are also required to have thermal protection to lower the temperature increase on the inside of the car. This can be achieved through insulation, tank car jackets, protective housings and underframes, and tank discontinuities.
Another aspect is to reduce the likelihood of derailment in the first place. While derailment can never be completely prevented, advanced coupling systems help reduce the risk. Tests are done at various speeds to ensure that couplers will hold, keeping cars on the track as much as possible.
The Role of Valves in Safety
Valves control flow and pressure during transit as well as loading. If high pressure is detected, relief valves can prevent explosion. Just as important, if the pressure in a tank car drops because of a leak, low-pressure relief valves allow air into the tank car to keep its equilibrium and prevent a potentially catastrophic implosion. Tank car implosions can be just as bad.
McKenzie Valve offers valve repair and replacement options as well as high-quality low-pressure relief valves to help preserve safety in transit. We can help you pick the right valve for your use case, based on our years of expertise. Our tank car valve refurbishment services help you keep tank cars in service. You can count on us to provide the right high-quality valves that meet or exceed standards.
The Foundation of Rail Tank Car Safety
Rail tank car safety is overseen by the Association of American Railroads (AAR). The AAR is not a government agency but sets voluntary standards that meet or exceed government regulations in the U.S. and Canada.
They set guidelines for safety and performance for all tank car components, including valves. All of our tank car safety valves meet AAR standards.
Why Following AAR Standards is Necessary
Again, AAR standards meet or exceed regulatory standards in both the U.S. and Canada, ensuring that you are fully compliant and will not face regulatory consequences in the event of an accident or after an inspection.
Because these standards are often higher, they ensure the safety and reliability of tank cars during transport. Major tank car accidents are now rare enough that they make the national news, and you don't want your company to be the one being highlighted
AAR standards also protect you from legal liabilities. In the event of an accident, you can demonstrate you did everything you could, reducing the risk of having to pay out an expensive settlement. They also keep your insurance company happy. Non-compliance can also introduce significant operational risks, such as being forced to remove a large number of cars from service or paying a hefty fine.
McKenzie Valve's Commitment to AAR Compliance
All of our products meet or exceed AAR standards for both performance and safety. We have a meticulous quality assurance process to ensure that every valve that leaves our facility is up to spec and compliant with the standards.
Balancing Performance With Reliability
Safety is paramount, but you can't afford to ignore performance, efficiency, and reliability. Avoiding downtime is also important. You need all of your cars running and transporting materials, not in the shop. Here are some tips:
Key Drivers of Efficiency
A well-designed, streamlined valve maximizes material flow, reducing loading times and helping you get your load moving faster. When it comes to pressure valves, they need to work all the time and not activate during loading.
You also need durable and low-maintenance components to reduce the amount of time cars have to be pulled for maintenance.
Maintenance and Inspection Practices
Proactive maintenance might seem to be expensive, but it significantly reduces the risk of downtime. Regularly inspect cars for wear and tear, especially valves, seals, brakes, and other critical parts.
Follow our guidelines for valve inspection and maintenance and know that we can refurbish old valves while providing you with an immediate replacement to reduce downtime.
Innovations in Tank Car Design
Modern tank cars don't look like those from fifty years ago. Modern materials are durable and lighter, reducing fuel costs.
Valve technology has also advanced. If you have older cars, upgrading to modern valves will enhance reliability and efficiency. The valves themselves are more energy-efficient and lighter. Automated valves react to heat and overpressure faster than a human watching a sensor can, ensuring immediate response in the event of an accident.
Lastly, modern rapid prototyping allows valves to be customized very precisely to your specific needs.
Choosing the Right Rail Tank Car Specifications For Your Needs
To choose the right tank car specifications, you need to take into account:
- Type of material to be transported.
- Quantity of material. There's no need to purchase large cars to transport small quantities, but for larger ones, you need to minimize the number of cars.
- Route conditions, including temperature, whether the route goes through populated areas, etc.
- Travel distances.
Pressure relief valves should take all of these into account.
Collaborating with Experts
McKenzie Valve can take these factors and use our expertise to help you choose appropriate components for your tank car. We will help you support safety and efficiency, and there's one more thing.
Sustainability and Environmental Considerations
You want your valves to have proper specifications to minimize spills and waste. You also want durable, long-lasting components to support sustainability efforts while reducing long-term costs.
McKenzie Valve's Commitment to Sustainability
We are absolutely committed to sustainability. We adhere to all environmental and safety regulations and are always looking for ways to make production more energy-efficient. By using high-quality materials and providing refurbishment we extend the life cycle of tank car components, further reducing energy and raw material needs.
Partnering for Success
Understanding rail tank car specifications is how you achieve the all-important balance of capacity, safety, and efficiency. McKenzie Valve is your expert partner who can guide you to the right high-quality products for your needs.
Explore our solutions for tank car components, all of them AAR certified to ensure reliable and compliant operations.
Visit McKenzie Valve's site today to find the valves and other components you need to maximize the safety, efficiency, and reliability of your tank cars.
