Use of structural lining systems

Although the application of 'inserted form' technology has been available for application to inaccessible pipe for several years, the application of sprayed form' technology in recent years has substantially reduced the cost of correcting degraded inaccessible pipe for structural strength, infiltration barrier, and corrosion/erosion resistance. In early 1999 the ASME approved a B and PV Code Section XI code case that provided the application of the 'inserted form' technology with certain requirements. The application of 'inserted form' technology for smaller pipes (less than four feet in diameter) and 'sprayed form' technology for larger pies (greater than two feet in diameter) can reduce the cost of replacing the buried pipe by a factor of three to ten. In addition the 'sprayed form' technology can be applied relatively quickly, thereby markedly reducing the out-of-service time required for the repair. (author)