How will the pipeline be inspected for build quality and deterioration?
Before the pipeline is tested all welds will have been inspected for defects by ultrasonic or radiographic techniques. The Pipeline Safety Regulations 1996 require National Grid to maintain the pipeline in good repair. The operator will carry out an on line inspection using an inspection tool, known as a pig, which is propelled inside the pipeline by the gas flow. The first inspection will take place early in the life of the pipeline and at scheduled intervals afterwards. Inspection pigs at the size of the Milford Haven pipeline (48 ins) are in use on existing NTS pipelines.
