API 510 Inspection Planning and Scheduling 5 — Questions and Answers
Question 1: When scheduling a pressure vessel inspection that requires entry, which prerequisite is mandated before an inspector enters the vessel?
- Painting the interior surface for better visibility
- Issuance of a confined space entry permit with atmospheric testing and lockout/tagout verification (Correct answer)
- Removal of all insulation from the exterior
- Written approval from the vessel manufacturer
Correct answer: Issuance of a confined space entry permit with atmospheric testing and lockout/tagout verification
Confined space entry permits require atmospheric testing for oxygen, combustibles, and toxics, along with lockout/tagout isolation of all energy sources before any person enters.
Question 2: What is the primary purpose of establishing baseline thickness measurements during the initial inspection of a new or newly installed pressure vessel?
- To verify the vessel meets ASME Section VIII construction requirements at that point
- To provide reference data so future corrosion rates can be accurately calculated (Correct answer)
- To satisfy the vessel manufacturer's warranty requirements
- To document the vessel's empty weight for transportation purposes
Correct answer: To provide reference data so future corrosion rates can be accurately calculated
Baseline readings establish the starting thickness from which future readings are compared, enabling accurate corrosion rate calculation and remaining life prediction.
Question 3: Under API 510, inspection intervals for pressure vessels operating at low temperatures where brittle fracture is a concern should be planned to include:
- Increased frequency of hydrostatic tests only
- Assessment of toughness requirements and review of any excursions below the minimum design metal temperature (MDMT) (Correct answer)
- Reduction in external inspection frequency
- Substitution of visual inspection for UT measurements
Correct answer: Assessment of toughness requirements and review of any excursions below the minimum design metal temperature (MDMT)
Vessels susceptible to brittle fracture require that inspection plans address toughness evaluation and document any operating temperature excursions below the vessel's MDMT.
Question 4: A pressure vessel is reclassified to a higher-severity service fluid. According to API 510, what should happen to the inspection schedule?
- No change is required until the next planned inspection
- The inspection schedule should be reviewed and potentially shortened to reflect the increased risk (Correct answer)
- The interval is automatically doubled to account for the reclassification paperwork time
- Only the external inspection frequency changes; internal remains the same
Correct answer: The inspection schedule should be reviewed and potentially shortened to reflect the increased risk
A change to more severe or hazardous service increases the consequence and potentially the probability of failure, warranting a review and likely shortening of the inspection interval.
Question 5: Which situation would justify postponing a scheduled internal inspection of a pressure vessel per API 510?
- The plant manager requests deferral to reduce maintenance costs
- The inspection engineer documents that on-stream inspection data confirms adequate remaining life and acceptable risk for the deferral period (Correct answer)
- The vessel has not experienced any visible external leaks
- An upcoming scheduled turnaround is only 3 years away
Correct answer: The inspection engineer documents that on-stream inspection data confirms adequate remaining life and acceptable risk for the deferral period
API 510 allows deferral of internal inspections when on-stream inspection results and documented risk assessment support continued safe operation through the deferral period.
Question 6: When planning inspections for a heat exchanger shell classified as a pressure vessel under API 510, which area deserves particular attention due to a common damage mechanism?
- The nameplate attachment weld only
- The shell-to-tubesheet junction and shell inlet nozzle area prone to flow-accelerated corrosion or erosion (Correct answer)
- The foundation bolting
- The lifting lug welds
Correct answer: The shell-to-tubesheet junction and shell inlet nozzle area prone to flow-accelerated corrosion or erosion
The inlet nozzle and shell-to-tubesheet junction areas experience high flow velocities and turbulence that promote erosion and flow-accelerated corrosion, making them priority inspection locations.
Question 7: Per API 510, the authorized inspector is responsible for doing which of the following as part of ongoing inspection planning?
- Setting the maximum allowable working pressure without engineering review
- Maintaining and updating inspection records and ensuring next inspection dates are tracked and met (Correct answer)
- Approving all process changes that affect vessel operating conditions
- Issuing new ASME nameplates when original ones are damaged
Correct answer: Maintaining and updating inspection records and ensuring next inspection dates are tracked and met
The authorized inspector maintains the vessel inspection record, updates it after each inspection, and tracks the next required inspection date to ensure compliance with API 510 intervals.
API 510 Inspection Planning and Scheduling 5
When scheduling a pressure vessel inspection that requires entry, which prerequisite is mandated before an inspector enters the vessel?