FAQ-207: Pro-rating ASME B31.8S intervals (11/10/2005)
Question: If a pipeline operating below 30% SMYS was pressure-tested at 1.5 times MAOP, can the reassessment interval in ASME B31.8S Table 3 be prorated?
Answer: If a hydrostatic pressure test was performed per Subpart J requirements, then the operator may use a seven-year reassessment interval. Extended intervals may be achieved per ASME B31.8S, Section 5, Table 3. If the Test Pressure ratio (or the Predicted Failure Pressure ratio) falls in between the intervals listed in ASME B31.8S-2001, Table 3, straight-line interpolation between the 5-, 10-, 15-, and 20-year intervals is acceptable.
FAQ-235: Use of Guided Wave Ultrasound as part of ICDA
Question: If Guided Wave UT is used as part of the ICDA process, is it considered “other technology” requiring notification to OPS/states?
Answer: Response is under development.
For more information on gas pipeline integrity management FAQ’s, go to: http://primis.phmsa.dot.gov/gasimp/faqlist.gim