pipeline test

NDT case study –

fire and sprinkler main installation in large factory

background

In November 2013 a new fire and sprinkler main were installed at a large factory site in northeast England. By November 2014, three failures had occurred on the installation. Impact Solutions were contacted by the main contractor for the factory site to conduct failure analysis on the faulty joints. Impact Solutions visited the factory site to discuss the problems and collected three electrofusion coupler joints and three butt fusion joints for destructive testing to WIS 4-32-08 at their lab. All of the joints tested failed the WIS standard test. This was put down to poor welding practice and a lack of QA/QC procedure. As a result, the contractor was forced to abandon the failed water main and to install a new one for their client.

the solution

Impact Solutions wrote a Quality Control/Quality Assurance procedure for destructive and non-destructive testing (NDT) of the new installation. The contractor stipulated that NDT was to be performed on all electrofusion couplers. In addition to this, the welders were retrained for best practice using impact solution’s external training consultants.

challenges

Due to the poor installation of the first main, the contractor for the factory incurred the cost of installing the replacement pipeline. The factory experienced a cost of £20,000 per minute in downtime because of the failed fire main.

During the new pipeline installation NDT was conducted on 42 electrofusion coupler joints challenges across a number of site visits. Two (~5%) of the 42 joints tested on the water main were identified by impact ndt as high risk and the contractor made the decision to replace them.

This is estimated to have the potential to save the client up to £10m assuming a half day of down time per joint failure.

As a result of the new quality assurance procedures, and the use of NDT on all new joints installed, the main contractor for the site can be sure and provide evidence that the fire main handed over to the client is of a very high standard and is not likely to cause extensive future problems during use.