Welding Pressure Vessels: How It’s Done

Pressure vessels are generally spherical or cylindrical metal containers designed to store high-pressure products. They make it possible to hold a higher volume of product than would be possible at atmospheric pressure. Pressure vessels are commonly used in the biopharma, food, chemical processing, oil and nuclear industries to generate power and store liquids, vapours and gases. Here’s an overview of some of the welding processes that can be used on pressure vessels.

Welding methods

Welding pressure vessels is a delicate process that must be done with extreme care. Any flaw in the welding process can have disastrous consequences once the vessel is in operation. The following types of welding are commonly used to weld pressure vessel joints:

• Shielded metal arc welding (SMAW) is a manual type of arc welding. SMAW equipment is inexpensive and portable. However, the welder must be highly skilled to produce high-quality results using this method.
• Flux-cored arc welding (FCAW) is a semi-automatic arc welding process used to weld thick metals. It’s similar to SMAW, but the operator doesn’t have to be nearly as skilled due to the continuous wire feed.
• Gas tungsten arc welding (GTAW) is an all-position welding process that uses a tungsten electrode and inert shielding gas. It creates very clean, high-quality welds with excellent fusion and penetration. However, it’s a slow process that can be difficult to master.
• Gas metal arc welding (GMAW) involves using a continuous wire-fed electrode and inert shielding gas. It’s one of the easiest welding processes to perform and makes welds that are cleaner than SMAW or FCAW.
• Submerged arc welding (SAW) requires the weldment to be submerged in flux to shield it from oxygen and other gases in the atmosphere. It’s a very clean welding process with a high rate of deposition.

When choosing the right welding process for your pressure vessels, you must consider the material the vessel will store or produce and the pressure the material will be under. For instance, pressure vessels are kept at relatively low pressure in the oil industry. As a result, SMAW and FCAW welding are frequently used because they are quick and inexpensive. However, vessels in the nuclear industry are under extremely high pressures and require high-quality, consistent results, like those provided with GMAW or SMAW.

Industrial pressure vessel welding

At Advanced Flow Systems, we offer expert welding services for pressure vessels, including helical coils for boilers and heaters. Our staff has extensive experience in welding complex assemblies to the finest detail. Contact us today for more information about our services.