Tank car valves protect everyone from hazardous material spills. Because they are so important, they need to work properly at all times. However, like anything else mechanical, they age. Proper maintenance can help, but sooner or later, valves have to be replaced.
The best way to extend the life of a valve is a regular rebuild. Valve reconditioning allows the valve to stay in service longer and ensures safety and compliance. In fact, regulations require that valves be rebuilt every ten years.
McKenzie Valve has been selling high-quality, AAR-certified tank car valves for years, but in 2022 they entered the valve rebuild business. Their goal is to provide reliable rebuilds that leverage our expertise, and they can recondition not only their own valves but all major brands.
This guide will provide some knowledge on valve reconditioning and rebuilding.
Understanding Valve Reconditioning and Rebuild
Tank cars have two main types of valves, which are the inlet/outlet valve and the pressure relief valve. The inlet/outlet valve, by its nature, collects liquid and potentially debris that can, over time, clog the valve.
Wear and tear also accumulate over time. The most obvious sign that a valve needs work is leakage, and tank cars are checked for leaks every time they are used. However, ideally, valves should be reconditioned before they start leaking, especially if toxic and hazardous chemicals are being transported. Leaks are rare, but even a small leak can impact the health of workers and wildlife in the area.
When a valve is reconditioned, it is thoroughly inspected and cleaned, and any worn components are repaired or replaced. The valve is then tested and recertified so it can be brought back into service quickly. Internal issues that aren't visible during a pre-loading inspection can be found during a rebuild. The refurbished valve should be as safe and efficient as a new valve.
To ensure this, the valve reconditioning process should focus on precision and adherence to safety standards. Using AAR standards is the best as they at least meet, and often exceed, regulatory requirements.
Downtime can be avoided by swapping out valves for new or refurbished ones while they are rebuilt. It can take a while to refurbish a valve. Ideally, this means you should swap valves out to reduce downtime and make the process more efficient. Valves should always be used for the materials they are rated for; resist the temptation to "just for now" swap in a different type of valve, as this can result in a serious incident.
The Step-by-Step Valve Rebuild Process
There are four main steps to the process:
Inspection
The valve is inspected to assess its overall condition. Some valves may not be good candidates for refurbishment and should instead be replaced. However, many defective valves can, in fact, be repaired, saving money and materials.
This inspection is more detailed than the normal visual inspection valves get on loading the car and during routine maintenance. A quick inspection can reveal a leak or other significant issue, but it will miss damage or defects that are likely to lead to a leak in the near future. The more detailed inspection that happens during a rebuild will flag these defects, and assess what repair work the valve needs.
Disassembly and Cleaning
Next, the valve is then taken apart and inspected further for internal problems. After that, it is thoroughly cleaned, removing the inevitable buildup of product and debris. This allows the repair technician to see any hidden problems, as well as ensure that the valve is returned to use clean, resulting in improved efficiency. Precise details of the cleaning process depend on what kind of materials or products the valve was exposed to. It has to be done carefully, using the right chemicals and cleaners to ensure a thorough cleaning and protect the safety of workers.
Each component is cleaned separately, ensuring that there is absolutely no residue remaining on the valve.
Repair or Replacement of Damaged Parts
The technician then assesses which parts of the valve need to be repaired or replaced. While repairing components is better, in some cases they may need to be replaced. O-rings commonly need to be replaced because they are subject to a lot of wear. A worn spring, on the other hand, may need to be replaced or it may be possible to refurbish it.
The goal is to restore the valve to a new condition so that it meets the standards to which it was originally certified. Rarely, it is possible to upgrade a valve to more recent standards during the rebuild process. However, if standards have changed significantly, you should consider replacing the valve with one built to the new standard.
Reassembly and Testing
Finally, the valve is then put back together carefully, matching the original configuration. It is thoroughly tested to ensure that its performance matches that of a new valve. Valves that fail testing may be put through the process again or may need to be discarded and replaced.
If the valve passes, it can then be put back into service on the appropriate tank car type. There is no safety or operational difference between a reconditioned valve and a new valve, and the valve can then be reconditioned again at a later date until it experiences a failure that warrants full replacement.
Benefits of Regular Valve Reconditioning
Reconditioning tank car valves regularly has a lot of benefits for you and your customer. These benefits include:
- Enhanced operational efficiency and safety. Reconditioned valves are less likely to leak and regular reconditioning catches problems before they become serious. Not only does this protect the public from hazardous chemicals, but it reduces the risk of delays caused by potential issues with valves when loading a car.
- Extend the lifespan of valves and reduce costs in the long term. Reconditioning valves helps them last longer, which typically saves more money over the long term than the cost of reconditioning. When a valve can be reconditioned instead of replaced, it saves money and also helps sustainability.
- Compliance with industry regulations and standards. Regulations require that valves be reconditioned at least every ten years. Using a certified provider ensures that the reconditioned valves continue to comply with the original AAR standards.
- Reduced downtime. Tank cars are less likely to be taken out of service due to, for example, a bottom valve leak. Unexpected failures become less frequent. Discovering a valve problem halfway through loading a car can result in huge delays and damage to a company's bottom line and reputation.
Regularly reconditioning your valves is cost-effective, paying for itself at multiple levels and helping you provide the service your customers expect and deserve. For maintenance facilities, ensuring your clients meet compliance and recondition valves when needed, is an important part of your job. However, it's not always something you can do on your own and without help.
Challenges in Valve Rebuild and How to Overcome Them
In addition to awareness of the value of valve rebuilds, the primary challenge is a shortage of shop capacity. Traditionally, valves were more likely to be replaced. As refurbishment becomes more common, there's a growing shortage of facilities that can do rebuilds, and many of the ones that do exist aren't certified. Without certification, there's no guarantee that reconditioned valves will be safe.
A car can end up being out of service for weeks while a facility is found to rebuild valves, and not all operators have the ability to switch out valves.
McKenzie Valve & Machining has an approach that helps dramatically. Instead of taking the valve, rebuilding it, and returning it, McKenzie will switch the valve for a reconditioned valve of the same type through our exchange program. The worn valve will then be reconditioned and eventually provided to a future customer. This means that tank cars are not sidelined while valves are rebuilt, saving time for our customers.
We are experienced, certified, and have state-of-the-art facilities to guarantee that our reconditioned valves are as good as new. The replacement valve you get will have been properly tested and will meet the same standards as a new valve. We do not send out valves that cannot be repaired or still have defects.
Our "send one, get one" approach is designed to overcome the challenge of limited space by reducing wait times for new valves.
McKenzie Valve & Machining's Rebuild Service
Our approach to valve reconditioning is simple:
- Inspection
- Rebuild
- Testing
- Reinstallation
We are committed to both quality and speed and have systems designed to provide the latter without compromising the former.
Regular valve reconditioning and rebuilds help you meet industry standards and are important for both safety and smooth operation. They reduce the risk of failures, which in the worst case can cause a major leak with public health implications, but which can also delay shipments, reduce capacity, and make extra work for people on the ground. Check out our website for more information and to explore our valve rebuild services.
Working with McKenzie is the best way to add valve rebuild services to your overall valve maintenance business. Let us help you get the most out of your capabilities and keep your business running smoothly.
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