Welding
Making welding attractive
Whilst welding is a high-precision task, the highprecision marks that are left are not always aesthetically pleasing. Although this( usually) has no effect on how the product functions, ensuring a clean finish is important to FHT Valves.
By Lyndsey Denton-Fray, Valve World
After listening to its customers and distributors, FHT Valves decided to move forward and improve the welding appearance on its finished products. FHT Valves originally used manual Tungsten Inert Gas( TIG) welding, which is a form of arc welding that uses a non-consumable tungsten electrode to produce the weld. Whilst this welding process is successful, FHT Valves has now moved on to using Laser Beam Welding( LBW) to enhance the finish of its products.
What is laser beam welding?
LBW is a high-precision welding process that uses a concentrated laser beam to join metals. The laser provides intense, focused heat that melts the material at the joint, allowing it to fuse together as it cools. LBW works by directing a high-energy laser beam at the product that needs to be welded. The laser then melts the material at the joint, creating a molten material that fuses together and solidifies, creating a strong weld. With LBW, a shielding gas, such as argon or helium, is usually used to prevent oxidation.
Differences between TIG and LBW
TIG has been an effective form of welding for many years by using an electrode to create an electric arc between the electrode and the product. The heat from the arc is what melts the product’ s base material, with a filler rod used to form the weld. Compared to LBW, a filler rod is not typically used, and the heat source is from the laser beam. As TIG welding relies on an electric arc between the electrode and the product to generate the heat to melt the material, the melted area can be less focused than in LBW. Due to the laser beam being a highly focused point, the heat from the laser heats a much more precise area for the weld, allowing for high precision and accuracy. This allows for a more detailed weld, which is ideal for smaller or more complex parts and products. TIG welding is still precise as it provides excellent control of the weld, but this comes more from the
Image one: Tungsten inert gas welding
skill of the operator as the process is often carried out manually, which can slow down the welding process in comparison with LBW. With the precise laser and concentrated heat in LBW, the weld can be created through thick materials more easily and quickly than TIG, whilst also being suitable for automated use. Another main difference between TIG welding and LBW is that TIG usually results in a larger heat affected zone( HAZ) as the heat from the arc is spread out over the surface of the material rather than in a more specific area, as with LBW. The laser beam in LBW is more precise, resulting in a lower HAZ, meaning there is less thermal damage to the rest of the product.
Making the switch
Whilst laser beam welding can be an expensive investment, FHT Valves deemed this important enough to meet its customer and distributors’ expectations. In image one, you can see the original appearance of TIG welding where the finish has a bumpy and raised surface. Whilst this generally has no impact on the functionality of the valve, the finish can be concerning for customers. Therefore, after discussion, FHT Valves decided to change its process to laser beam welding. In image two, you can see a wafer ball valve with a heating jacket welded with laser beam welding. As the images show, using LBW creates a smoother and neater finish, which was what customers desired from a finished product.
About FHT Valves FHT Valves is a manufacture of ball valves, including the production of industrial ball valves, 3-way ball valves and customer-made valves. With 25 years of experience, they continue to expand their production range and expertise.
Image two: Laser beam welding
24 Valve World May 2025 www. valve-world. net