Weld-After-Backfill (WAB) is a pipe welding process in which a steel pipeline is installed and backfilled prior to the welding operation, the pipe can then be welded at a later date. This keeps the pipe welding out of the critical path of the project and allows both the welding and the installation operation to move forward without being hindered by the other. This method is recognized by AWWA C206 and C604 as an acceptable water pipe installation and welding method.  See AWWA Standards links below.

It is important to note that although WAB is an extremely efficient pipe welding method, it does come with its own set of difficulties that must be considered to ensure the project is a success. Soil condition, backfill material, steel thickness, ground water, and improper installation techniques can all have adverse effects on the efficiency of the WAB process. National Welding has been welding pipe using the WAB method since its inception and has the knowledge and capability to help you successfully through your WAB project. If you would like more information please give us a call.

Project Links:

AWWA C206-17 Field Welding of Steel Water Pipe

AWWA C604-17 Installation of Buried Steel Water Pipe—4 In. (100 mm) and Larger

Related Presentations

Weld-After-Backfill Application on steel pipelines

ABSTRACT; Weld-After-Backfill application is a method to install steel pipelines and  is a growing practice. This short slide show provides photographs of the general steps for this process and provides caution against using incorrect materials for this method. This sequence of pipeline construction was first used in the late 1980’s on a pipeline in Texas.  … Continued


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