Welding Technology

Challenges
With an aging pipeline infrastructure, the trend toward higher grade steel and increased regulatory oversight, pipeline welding is becoming both more critical and more challenging. DNV has the technical expertise and industry experience to address all of your pipeline welding concerns.

Welding Procedures and Qualification
We can support your welding procedure development and qualification needs from beginning to end, with experience not only in writing procedures, but with on-site qualification. We can generate all of the documentation necessary to comply with industry standards such as API 1104, CSA Z662, and ASME Section IX. We have experience with many processes including shielded metal arc welding, gas metal arc welding, flux-core arc welding, and gas tungsten arc welding. We also have experience qualifying in-service repair and hot tap welding procedures, low hydrogen procedures, stainless steel procedures, and procedures for high strength material.

Regulatory Compliance and Best Practices
DNV actively participates in many of the professional organizations that author pipeline regulations. We have an intimate knowledge of these documents and their intent. We can audit welding procedures and operating procedures to ensure they comply with regulations and follow current industry best practices. We also offer an extensive laboratory equipped to handle a variety of research projects.

In-Service Welding
Welding onto an in-service pipeline is advantageous in that it allows cost-effective installation of branch connections (hot taps) and repair sleeves by avoiding the loss of pipeline throughput and contents. There are inherent risks, such as hydrogen cracking and burnthrough, associated with welding onto pipelines that contain pressurized fuel gasses or petroleum products. Errors during in-service welding can at best negate the advantages and at worst can result in costly unscheduled outages, damage to the environment, and injury to personnel or the public. There are many factors to consider when welding onto an in-service pipeline such as wall thickness, material grade, chemical composition, flow conditions, operating pressure, fatigue cycling, the welding process and consumables, the weight of the repair, etc. DNV has unparalleled industry experience working with in-service welding. We have published papers, regularly teach a course on repair and in-service welding, and work with clients on a regular basis with their in-service welding issues.