Valves are an essential part of industrial piping systems. When they don’t work properly, systems are at risk of failing, causing downtime, and ultimately, a loss of income. When valves are manufactured, they are leak tested to make sure that their seats hold and they maintain integrity. Jacketed valves are needed in systems where maintaining the fluid produced in industrial lines at a specific temperature is required, so the media’s properties are conserved throughout the manufacturing process. They help prevent valves from freezing up and causing lines to fail.
There are different types of valve jackets, including clamp-on and weld-on. Which type to use depends on the level of the flow media, the temperature it undergoes, and the pressure involved in the system. Additionally, there are different ways industrial plants can have jackets for valves manufactured and applied. Some options are better than others when it comes to reducing system failures and overall valve integrity.
Clamp-On Valve Jackets vs. Weld-On Valve Jackets
Clamp-on valve jackets can be supplied as a fabricated unit or cast out of metal. These types of jackets have advantages and disadvantages. Firstly, if, for some reason, there is a failure in a clamp-on jacket, there is no cross-contamination to deal with. Secondly, these jackets are reusable. However, the drawbacks of clamp-on jackets may outweigh the benefits. Clamp-on valve jackets don’t have sufficient thermal process heat transfer for many applications. Additionally, having clamp-on jackets made means giving the valve to a manufacturer to complete a pattern and then cast the jacket. This takes time, so the wait time for delivery can be long.
Weld-on valve jackets also come with pros and cons. However, with this type of valve jacket, the positives often outweigh the negatives. Jackets that are welded directly onto the valve provide superior heat transfer to the clamp-on type. The downside is that weld-on jackets are not reusable.
While weld-on jackets may clearly be the better option in most cases, there are risks of them failing when end users don’t choose the right manufacturer and application process. For example, if a facility chooses to just have somebody like a piping contractor go weld on it, there is a tendency to warp the seats (especially if it’s a stainless valve). It can cause a deformation during the welding process in the valve, causing the valve to stop functioning as an isolating valve. It simply will not hold, and it will require repair or replacement.
What is the Best Application Process for Valve Jackets?
Maintaining seat integrity when producing fabricated weld-on jackets for valves is critical. In the above example, the right type of jacket may have been selected, but the application process negated the benefits.
Achieving a jacketed valve can be approached in a couple of different ways. The industrial facility can go back to the manufacturer to have it done, but that means that the facility is on the hook for maintenance and repairs afterward. Alternatively, the plant can have the jacket done aftermarket by an independent contractor who is certified and capable of performing the application properly.
In an ideal world, if it is at all possible, plants are best served by a single contractor who can create the jacketed valve and provide repair and maintenance as well. There are companies out there that operate that way, but there aren’t many. It may require plants that require jacketed valves for their system to do some research and investigation when choosing the company but doing so helps ensure that the application is made correctly and that any future repair or maintenance is covered.
Final Thoughts about Process Valve Jackets
In all process industries, failures due to improper valve jacketing happen all the time. Valves are precision flow-control devices. Their proper function depends on the overall integrity of both valve and jacket. Properly jacketed valves may only be a small portion of total operating costs, but they are vital to the two factors that matter most in industrial settings – uptime and throughput. Don’t risk choosing the wrong type of valve jacket or an ineffective application process if you don’t have to.