HDD are usually installed in areas where the pipe is impractical to repair, so they have to comply with the full design life requirements of the pipeline with no repair option. There are a number of circumstances in which pipe in HDD can not be cathodically protected and can be subject to high rates of corrosion. In spite of this the acceptance criteria for pipe in HDD is of a lower standard than would be accepted for normal trenched construction.
展开▼
