Determining marine pipe quality

In the majority of vessels, marine piping systems are designed, constructed, and inspected by the shipyard in accordance with classification society rules. Inspection requirements imposed on maune piping systems are either visual or radiographic; the level of inspection of the latter can vary from 0 (at the discretion of the surveyor) to 10% to 100%. With the introcuon on of the U.K. Design and Construction Regulations (DCR) SI 913 (Ref. 1), U.K. doaning production, storage, and offioading (FPSO) vessel operators have the cotion to disregard or maintain class once the vessel has been installed offshore providad all sziety-critical items have been identified. Marine plaing systems that operate at high prassures or temperatures are classified as safety critical and are required to be inspected during construction and at regular intervals during production to ensure the integrty of the system has not been impaired. Offshore operators conteniplating the construction or conversion of a tanker to an FPSO seldom cuestion the standard of weld quailty of marine piping. However, it is doubtful class requirements are suitable for FPSO marine piping.