NBBI Inservice Inspector (IS) case studies
NBBI Inservice Inspector (IS) · Put your knowledge to work in context.
The National Board Inservice Inspector (IS) credential is issued by The National Board of Boiler and Pressure Vessel Inspectors (NBBI), the organization whose site lists commissioned inspectors, pressure equipment inspectors, and inspection organizations among its credential and accreditation programs. The IS credential is aimed at inspectors who examine boilers and pressure vessels already in service rather than at the point of new construction, and who must judge whether that equipment remains safe to operate under the National Board Inspection Code (NBIC). The NBBI Inservice Inspector (IS) case studies are 5 cases and about 2,564 words.
1Weeping Crack in a Firetube Boiler Shell Weld
During an internal inspection of a 30,000 lb/hr, 150-psig firetube boiler, the authorized inspector finds a 3-inch longitudinal crack in the shell-to-tube sheet weld at the rear turn-around. The crack is visible with the naked eye, and a small amount of water seeps from it after the boiler is filled for hydro.
572 words, about 3 min2Local Thin Area in a Pressure Vessel Shell Under Insulation
An inservice inspector is reviewing a vertical pressure vessel, 60-inch inside diameter, SA-516 Gr. 70 shell, design 150 psig at 400 degrees F, joint efficiency 1.0, corrosion allowance 0.125 inch.
516 words, about 3 min3Replacing a Small Drain With a Larger Flanged Nozzle
A plant has a 48-inch-diameter, 200-psig horizontal pressure vessel, SA-516 Gr. 70, built to ASME Section VIII Div.
463 words, about 2 min4Steam Safety Valve With High Set Pressure and Excessive Blowdown
A steam boiler has a MAWP of 250 psig and a required relief capacity of 12,000 lb/hr. The installed safety valve is a direct-spring valve with a set-pressure nameplate of 250 psig and a rated capacity of 13,500 lb/hr at 250 psig.
512 words, about 3 min5Welded Patch With an R Stamp but No Repair Records
During an external inspection of an 800-gallon air receiver, the inspector finds a welded patch on the shell near the bottom head. The patch is 8 inches by 10 inches and is welded to the shell.
501 words, about 3 min