Industry-leading engineered repair and upgrade solutions

Delayed coking has been in use since before the 1950s. Because delayed coking is a batch process, the components involved see significant temperature and pressure fluctuations during operation that are not common in other refinery assets. These cyclic changes cause low cycle fatigue failure mechanisms in the coker drums of the system. Since these drums are extremely costly to replace and are a critical asset, solutions that extend life, shorten turnaround cycles, and improve operational reliability and safety are of prime importance.

WSI has provided advanced repair options to address the more prevalent coke drum failures for decades. This includes bulging and cracking of the pressure boundary shell, cracking of the support skirt to shell interface weld area, and cladding damage of the lower cone. Today, WSI is the largest provider in the industry of structural repairs for coke drums.

Our unique process consists of installing a highly engineered weld metal overlay to the existing vessel to modify the structure of the vessel to mitigate bulging and cracking caused by the low cycle fatigue mechanisms to which the vessels are exposed.

Because the welding parameters are tightly controlled by the use of closed-loop automated welding systems, controlled deposition techniques (temperbead) are implemented to eliminate the need to perform post-weld heat treatment of the deposit. This approach has been implemented in over 100 coke drums throughout the world with flawless performance.

For support skirt crack repairs, WSI utilizes proprietary welding processes to replace the critical welds and, in some cases, install new sections of skirt, also without requirement for post-weld heat treatment. With dozens of skirt repairs installed throughout the industry without subsequent cracking, this approach has been demonstrated to be superior to conventional methods of repair.

Our long history in the development and implementation of specialty coke drum life extension and repair processes positions us to be your primary source for coke drum reliability.

WSI engineered solutions for coke drums

• Bulge repair and structural shell reinforcement
• Lower cone replacement welds utilizing the HotPulse^® critical weld process
• Shell and support skirt crack repair
• ID cladding damage and defect repair

Specialty machine welding solutions specifically configured to address difficult welds

Product heaters and furnaces are some of the most common components in any refinery. Many refiners are in the process of upgrading the metallurgy of these components to reduce degradation and maintenance costs. Since these replacements involve a large number of orbital welds and these welds are performed in-situ, the high preheat requirements and difficult geometry often cause significant weld failures. Advanced materials are not very forgiving to multiple repairs, which creates a difficult challenge in meeting quality and schedule requirements. WSI has developed HotPulse^®-enabled specialty machine welding systems specifically configured to make these difficult U-Bend welds. The equipment safely places the operator away from the discomfort of the high preheat and, because of the HotPulse technology, provides an extremely high-quality GTAW weld at high production rates. When high alloy base materials such as 9CrV are used, the mechanical and chemical properties of the welds are also significantly improved over conventional welding.

Watch our U-Bend welding video to learn more about our welding solutions.

Industry leading solutions to protect boiler components against high temperature erosion/corrosion

Power boilers in refineries are often overlooked components–until they have a forced shutdown that affects production. Refinery boilers suffer from the same failure mechanisms as power generation boilers: sulfidation corrosion, thermal fatigue cracking, water chemistry corrosion, flame impingement damage on waterwalls, and high temperature creep. In the power generation field, WSI is a leader in boiler tube overlay and the protection of boiler components against high-temperature erosion/corrosion and other damage. Our weld overlay product has been applied throughout the power generation industry. Our Unifuse® weld overlay shop and field applied products are the most common corrosion protection method for boiler erosion/corrosion.

Superior pressure boundary restoration and corrosion/erosion control

To overcome the potential challenges affecting nozzles in vessels, such as wall thinning, pitting, cracking and corrosion/erosion, our fully automated weld technology and weld overlay solutions offer an onsite solution to address corrosion issues in nozzles from 2 to 24 inches in diameter. Patented Unifuse® processes enable us to build up wall thickness to restore the pressure boundary and to apply an improved metallurgy to reduce the effects of corrosion or the combined corrosion/erosion process, delivering the same high-quality deposit, thus avoiding expensive replacement costs.

Turn to WSI for machine orbital welding services during planned or emergent outages

As operational requirements increase, the use of advanced materials in piping systems has become the norm. Weight reduction, corrosion performance and mechanical failure mitigation in aggressive operating environments facilitated by improvements in materials and construction practices increase profitability and safety. 

WSI is the largest provider of machine orbital welding services for refineries, nuclear plants, and fossil plants. Our revolutionary HotPulse^® enabled orbital welding equipment provides both mechanical properties and volumetric quality better than conventional field welding processes, and with deposition rates competitive with SMAW and FCAW. This recent technology has been implemented on several major piping replacement projects to date, and has exceeded quality and schedule expectations, while being completed safely. That is why more plant operators turn to WSI for machine orbital pipe welding services during planned or emergent outage.